Ben's Blog on Discs

[Nooch]

http://serotta.com/the-candyman-vs-momentum-and-inertia/

Interesting read.

[Ahneida Ride]

Bill McDonald did the paint !

[BumbleBeeDave]

Oh, my . . . :eek:

BBD

[jpw]

behold, the future!

I'll take one, and sign the legal liability waiver.

Is that a Serotta fork?

[false_Aest]

Ser-pala
Chev-otta
Ser-vy
Imp-otta

Che-ve?
Pav-vy?

[jpw]

"censored" - what can it be?

[rice rocket]

http://www.reactiongifs.com/wp-content/uploads/2011/05/scarjo_popcorn.gif

[rustylion]

Yes, a newly designed/tested Serotta fork courtesy of Ben/Mike/Scott/Patrick.

Thanks.

behold, the future!

I'll take one, and sign the legal liability waiver.

Is that a Serotta fork?

[veggieburger]

Love the rear seat stay.
Love the orange, silver and black.
The decal work reminds me of a bad bicep tattoo...I can do without it.
Otherwise, nice!

[dd74]

That's cool. I like it.

[jpw]

Yes, a newly designed/tested Serotta fork courtesy of Ben/Mike/Scott/Patrick.

Thanks.

do you know the span of that fork? thx.

[pakora]

Ben's argument that is.

Love my XT hydros on dirt.
Love my Mavic SSCs on notdirt.
I'll totally ride road lever hydro discs for cross and dirt as soon as the price takes a dive.

I had a hydraulic disc brake on my winter bike just because I had some parts I wasn't using and thought it would be funny. The first time I braked on snow on an icy patch heh not funny.

[kevinvc]

This was a really interesting read for me: a newbie who has been looking at road bikes with disc brakes. I might not be 200 lbs., but I am the guy he mentions in the article who does fast descents, tends to ride the brakes too much and doesn't have the best cornering skills.

Thanks for the extra food for thought

[jpw]

Ben's argument that is.

Love my XT hydros on dirt.
Love my Mavic SSCs on notdirt.
I'll totally ride road lever hydro discs for cross and dirt as soon as the price takes a dive.

I had a hydraulic disc brake on my winter bike just because I had some parts I wasn't using and thought it would be funny. The first time I braked on snow on an icy patch heh not funny.

no studded tires? interesting.

[jds108]

Me likey! Maybe we'll see something like this sans the discs...

[pdmtong]

Had to get Rapha in there . . .

Probably not the glory-through-suffering theme Rapha had in mind when they made that kit that just went over the cliff.

Actually I had a nice chuckle when I read that.

I thought it was a good positioning piece that said a lot about the company - technically, philosophically, ethically.

[jpw]

what are those two black bits sticking out under the down tube?

[Bostic]

Wow this bike is beautiful!

Get some Shimano CX75 mechanical disc brakes on that bike! They are much nicer than the Avid BB7s that have been around forever. I'm waiting for Sea Otter before I jump ship. Running BB7's on my Volagi Liscio but want to move to either the Shimano CX75 or the TRP Spyre's.

[timto]

what are those two black bits sticking out under the down tube?

looks like clips/zip ties from holding the full cable housing for the rear brakes to the stops on the dt.

[1/2 Wheeler]

Nice read and it will give the masses a reason to throw Ben under the bus when Serotta offers a Disc road bike in the next year or two.

I think he should have done some testing where they try to over heat the brakes before declaring it a problem.


What I don't understand with the overheating conversation is how they work so well on MTBs. Are the descents shorter off road? Are they less technical so you don't have to ride the brakes as much?

[93legendti]

Like it

[rnhood]

Great looking bike and no doubt its well thought out.

[Bruce K]

I would say that most long mountain descents are longer than MTB ones and that a rider not allowing brakes to cool would be a much bigger issue on the road

Stopping from 50 vs stopping from 25/30 = a big difference

There may be more to it but thus kinda makes sense to me as a potential issue

BK

[Anarchist]

disc brakes on road bikes are the triumph of marketing.

completely unneeded and with the ability to over-brake the tiny rubber conatct patch, a solution where there was no problem.

[1/2 Wheeler]

I would say that most long mountain descents are longer than MTB ones and that a rider not allowing brakes to cool would be a much bigger issue on the road

Stopping from 50 vs stopping from 25/30 = a big difference

There may be more to it but thus kinda makes sense to me as a potential issue

BK

You are mostly likely correct. Top end speed and the force required to slow/stop at higher speeds is most likely the issue.

[Bostic]

I'm 5' 7" 143lbs, have about 3700 miles on my Volagi Liscio with Avid BB7 disc brakes. Currently running Sram Force 2013 levers, had Ultegra 6703 levers before. 160 HSX front, 140 HSX rear heat shedding Avid rotors.

When I first built up the bike it had sintered metal pads. I climbed and descended the most difficult road in Silicon Valley, Bohlman & On Orbit in Saratoga. Constant 14%-21% grades, no issues on the descent.

No issues on the Alta Alpina double century which goes up and down 8 mountain passes, 21,000' climbing. Nothing too steep other than some parts of Ebbet's Pass.

Fast forward to a few weeks ago, I had replaced the pads with Avid juicy organic compound. Did a group ride that went up and down the hardest climb in the East Bay Area, Welch Creek. About the same as Bohlman, a lot of 15%-20% grades. On the descent with the organic pads I was worried. The brakes were squealing and fading, and I wasn't riding the brakes. After that ride I promptly ditched the organic pads and went back to sintered metal.

I've taken the bike to work in a few downpours and other than the Avid brakes and rotors squealing something awful initially, they worked just as well as when on dry pavement.

[54ny77]

nice april fool's bike!

[rwsaunders]

That was a good read from Ben...a little behind the scenes R&D conversation.

[Jason E]

Not preachy or unfounded bravado. Fair and reasonable perspective. Others can disagree, but that sounded less like marketing and more about why SEROTTA is not ready for discs, not that everyone else is a fool.

Interesting read, too.

Thanks Ben!

[Lovetoclimb]

What an excellent review and insight into the mind of a businessman. So incredibly happy with my threaded bottom bracket and standard road calipers!

[the bottle ride]

I am just horrified by the mixing of the Sram and Shimano :)

I like the bike- I would be curious to see it with bigger tires.

[charliedid]

haha

[Cat3roadracer]

I love the concept, but being in a pile up this past Satruday at the local race, no one was sliced by a beautifully machined piece of stainless steel.

[GeekBoy]

I am just horrified by the mixing of the Sram and Shimano :)


At least as it's not Campy and one of the S-brands. *shudder*

[lukasz]

Haven't a lot of tandem riders been using discs for going on 10 years now?

I don't care about them in the slightest on a traditional road bike, but once you get into fat tire territory it is going to be mini-v, cantilever, or sometimes long reach calipers (if you're lucky?). I've seen people say that cantis can stop great but I've never experienced it myself. They stop, but I've not liked the feel and when I came close to getting them set up well the geometry changed due to brake pad wear. That's where I'd prefer road discs.

[reggiebaseball]

I think it is nice to see an honest builder not just throwing sh*t on a bike because a dentist asked for it.

[Kirk007]

Flying downhill at Whistler on a fifty pound downhill sled requires some stopping power and I've seen folks overheat rotors up there. And there are some big guys on those bikes. Brake fade when flying towards a gap in some trees at the top of a drop can make you pucker (at least it makes me pucker). The point, I dunno - brake fade can be an issue on a mountain bike and they deal with it with big ass rotors and hydraulics, which for a typical road bike, well, do you want 203 mm rotors on your flyweight climbing bike? On the other hand Dave Kirk recounts spending a good part of a summer flying down Montana passes with his disc prototype and not having a problem (all right Dave's skills are not the ones Ben is worried about).

I think there is a market for this bike for some riders; not all, and I can understand a larger manufacturers' liability concerns.

If nothing else though, I love the lines of that Fork; much better aesthetic in my view than their current road forks, particularly as headtubes get burlier. I hope that design carries over.

[HillDancer]

...do you want 203 mm rotors on your flyweight climbing bike?...
If one can appreciate precise modulation and low lever effort when needed most, then absolutely yes. If one hasn't experienced superior braking performance beyond what one is using, then how can one speculate with certainty it wouldn't be useful?

Stating the obvious, climbing will inevitably lead to descents, it's not just one way going up. My descents usually have a technical component, blind corners, and always the possibility of unpredictable motorist behavior. I have 200mm rotors up front, 180mm in the rear, mechanical calipers with a great pad compound (SwissStop FTW), on my not-so-flyweight road bike. No fading behavior, or noise, or the other imagined drawbacks speculators claim. Two finger braking from the hoods, one finger from the drops. It's much easier for me to control braking at the threshold of lock-up by finessing one finger using disc brakes, than attempting to control multiple muscle groups when grasping a rim brake lever with clinched fist.

[dd74]

Disc brakes aren't the problem, but just another solution. The real issue is knowing how to brake.

I learned how to brake from track days in a race car: prepare to go in deep at a curve, whether or not it's downhill, then pounce hard on the middle pedal at the curve's beginning only to adjust you to the corner and afterwards the machine you're on/in (bike or car)

Afterwards, the tires will scrub off speed depending on how far you decide to lean (a bike), or how hard you turn the front wheels (in a car).

Trailing the brake just wears out the materials and shows a rider's (or driver's) lack of confidence of what is at hand.

[jpw]

disc brakes on road bikes are the triumph of marketing.

completely unneeded and with the ability to over-brake the tiny rubber conatct patch, a solution where there was no problem.

rain.

[jpw]

I think it is nice to see an honest builder not just throwing sh*t on a bike because a dentist asked for it.

WHAT a cliche :rolleyes:

[jpw]

what's the biggest 650b tire that fits in that frameset?

what's the size of that head tube?

life is short.

[WickedWheels]

It's a bit of a tough one...

On one hand there is some merit for disc brakes because of:
- rain and foul weather
- rim wear
- not melting tubular glue
- eventually having lighter rims

One the flip side:
- having to beef up a frame and especially a fork to handle the load... and having that affect the ride quality
- having road bike standard that should be modified to deal with this (perhaps through axles on road bikes?)
- most of us simply not needing much stopping power to get a tiny patch of rubber to start skidding over pavement

Would Beloki have had a longer career if discs kept his tubular glue from melting? How many other riders would have had a shorter career from rotor slices in a pile up?

Either way, something like this will take years and years before it can be a truly viable option, but if no one tries it then it won't be developed. So who wants to be a crash test dummy?

Personally, I'm not going to be stocking any or pushing any at my shop for a while. If someone wants it then it will be a "special order" item. But I'm building myself a disc-brake equipped commuter with a belt drive, internally geared hub and a Schmidt generator set up just to try it out. I figured that I should "take one for the team" and see if it has any real merit.

[jpw]

I tell you what Serotta should do.

Offer the disc fork in a standard span as an aftermarket 'upgrade' as a winter option for Legend, Ottrott, and Meivici owners, and then wait for feedback.

[martl]

rain.

True, calipers behave differently in the wet (not necessarily worse, but different). Also true is that calipers provide more than enough stopping power.

Disks have advantages - no rim heating, no rim stress/wear, sometimes better modulation, less weather impact. Calipers also have advantages - wheel interchangeability, weight, cooperation with shift-brake-levers, easy maintenance.

As a retro-grouch, i feel i won't benefit enough from the disks theoretical or practical advantages and i can well live with old style calipers.

Also i don't think too many recreational cyclists do really have the *need* for disk brakes. But as we know, cycling isn't always about pure rationalism, it is also being thrilled by new technologies, at least for some of us.

I'm just sceptic about any new trends and inventions that thwart the simplicity of the bike as a tool, because that is part of its fascination. Reduction to tha absolute necessary minimum. But that's just me. Other folks love to garnish their rides with 3 different computers, rear view mirrors, electronic indicators, and whatnot, and that's also fine :)

[jpw]

True, calipers behave differently in the wet (not necessarily worse, but different). Also true is that calipers provide more than enough stopping power.

Disks have advantages - no rim heating, no rim stress/wear, sometimes better modulation, less weather impact. Calipers also have advantages - wheel interchangeability, weight, cooperation with shift-brake-levers, easy maintenance.

As a retro-grouch, i feel i won't benefit enough from the disks theoretical or practical advantages and i can well live with old style calipers.

Also i don't think too many recreational cyclists do really have the *need* for disk brakes. But as we know, cycling isn't always about pure rationalism, it is also being thrilled by new technologies, at least for some of us.

I'm just sceptic about any new trends and inventions that thwart the simplicity of the bike as a tool, because that is part of its fascination. Reduction to tha absolute necessary minimum. But that's just me. Other folks love to garnish their rides with 3 different computers, rear view mirrors, electronic indicators, and whatnot, and that's also fine :)

I'm all for minimalism. Cycling is an outdoor activity. There are many fair weather cyclists.

This is my formula;

bike + descent + rain = disc:)

[Chance]

Almost all designs have both advantages and disadvantages. Very few things are close to perfection. And that includes disc brakes. In my opinion it comes down to where the scales tip between pros and cons for our particular needs.

No doubt disc brakes offer improved braking under some conditions. Pointing out disadvantages doesn’t invalidate these better-braking claims. Additionally, discs allow for some non-brake bike-design flexibility like fenders and so on. But they do have disadvantages. For my particular needs discs seem unwarranted. Disadvantages outweigh advantages by a significant margin at this time:

More weight
More cost
More maintenance
Lower heat capacity
Too much power
Asymmetrical fork loading
Asymmetrical frame loading
Asymmetrical front wheel
Require non-radial front wheel

These are mostly minor disadvantages, but cumulatively disc braking advantages don’t tip the scale for me. Would be tempted to try them first on a tandem, which may seem counterintuitive.

[the bottle ride]

I don't think you can claim added maintenance for discs - takes me less time to swap pads on disc brakes than on my road bike.

Too much power? I have never heard any moto cat complain that his brembo's worked too well... Same thing for bikes- I never complained once about my magura gustavs having too much power (closest thing to a moto brake).

I will take disc brakes over anything else on long descents- less hand fatigue and less heat on the rim (which I think is a genuine concern on European style alpine roads- seen tubulars roll and seen an inner tube burst from too much heat).

I just need to wear out my Ti IF to justify to get a disc specific bike :)

[spaced_ghost]

that paint is hideous. halloween x tribal collabo. no thanks.

[Chance]

Disc maintenance with hydraulic systems is not limited to replacing pads.

Too much power is a real concern if the front brake can lock-up the front wheel too easily. A startled cyclist could very well end up going over the bars if he/she grabs too much brake. Saw a friend’s rear tire come completely off pavement recently when an animal suddenly ran in front of the bike. A little more speed and it could have been a disaster.

And yes, a “perfectly skilled” cyclist wouldn’t do this at all. But in reality most cyclists are not as proficient as they think they are in a true emergency. And to Ben’s point, these bikes will be ridden by all types of cyclists in all kinds of conditions.

[rugbysecondrow]

I like the bike...give it to me butt naked though. :banana:

[jpw]

I like the bike...give it to me butt naked though. :banana:

yes, the paint distracts from the prototyping.

[oldpotatoe]

Oh, my . . . :eek:

BBD

Ti and internal electronic. Wet discs and the road bike will happen but there will be more than a few who lose their brakes coming outta Ward..for a dry day, enthusiast's bike..even with carbon rims(teeny , tiny part of the market)..expensive, complicated, heavier...sorry, don't get it. Another MTB 'innovation'm trying to get onto a road bike. Tubeless, oversized headtubes, when are thru axles comin?

"I have a disc brake. 622mm rotor, rubber compound pads..works great."

[sparky33]

I'm all for minimalism. Cycling is an outdoor activity. There are many fair weather cyclists.

This is my formula;

bike + descent + rain = disc:)

In this context I'm on board. Otherwise, I give discs a solid *meh*.

[jpw]

In this context I'm on board. Otherwise, I give discs a solid *meh*.

The Poggio looked quite lethal this year.

[rustylion]

Last night, Scott and Mike reached out to me after reading my post in this thread.

I am retracting my "yes, that's a new fork" statement.

Yes, we have several new forks in testing and/or completed for bikes that are in development and/or close to commercial release.

No, the fork on the PAVE is not one of them because, as Ben has written about recently, the PAVE is not "for Serotta's prime time" yet.

So, egg on my face and another reminder to me to remain in my sandbox and publicly venture outside of it with care.

Sorry I caused confusion and thanks.

[BenSerotta]

There have been several comments about the fork...
As we were not yet committed to the project we used an Enve fork for the prototype. The span is 39.5CM with 4.7CM rake. Everyone agrees it's a pretty nice looking piece of work. Should we go forward with a similar bicycle, we'll likely be producing our own fork. I'm not implying anything here, other than our preference is to manage the ride stem to stern.
Regards,
Ben

[rugbysecondrow]

There have been several comments about the fork...
As we were not yet committed to the project we used an Enve fork for the prototype. The span is 39.5CM with 4.7CM rake. Everyone agrees it's a pretty nice looking piece of work. Should we go forward with a similar bicycle, we'll likely be producing our own fork. I'm not implying anything here, other than our preference is to manage the ride stem to stern.
Regards,
Ben

Thanks. I like it as a concept and look forward to seeing how it develops. Very cool and exciting.

Cheers

[jpw]

There have been several comments about the fork...
As we were not yet committed to the project we used an Enve fork for the prototype. The span is 39.5CM with 4.7CM rake. Everyone agrees it's a pretty nice looking piece of work. Should we go forward with a similar bicycle, we'll likely be producing our own fork. I'm not implying anything here, other than our preference is to manage the ride stem to stern.
Regards,
Ben

Ah, so it's a cross fork, and at 395 x 4.7 is exactly like my super stiff Wound Up, one I don't recommend unless the rider is BIG.

Thanks for the clarification.

P.S. was there a technical reason why you didn't fancy using the Enve road disc fork at 367 x 4.3 for 28mm tires (not sure when it came out)?;

http://www.enve.com/forks/road-disc.aspx

[FlashUNC]

As a lay person, I love seeing these kind of test mules (though maybe that's not entirely the right word) from companies, whether its cars or bikes or whatever.

Gives you the kind of insight into what Ben and the folks are thinking about not only where we are, but possibly where we're going.

[jamesutiopia]

I think Ben is tilting against windmills, but am in total agreement on this. Disc frames always need to be stronger than a normal (symmetrical) frame. For my money, I want a frame that is as strong as it needs to be, and no more.

On tandems and city bikes I don't really care about weight, so disc brakes all around.

[BumbleBeeDave]

The basic road bike is the fruit over over 100 years of optimization . . . I think Ben is tilting against windmills, but am in total agreement on this. Disc frames always need to be stronger than a normal (symmetrical) frame. For my money, I want a frame that is as strong as it needs to be, and no more.

On tandems and city bikes I don't really care about weight, so disc brakes all around.

I always thought tilting at windmills meant attacking imaginary enemies, or fighting unwinnable or futile battles. I don't see what they are doing with this test bike as being that at all. to me it's only tilting at a windmill if you have given up hope of every improving on the design of road bikes simply because they have been refined over 100 years. Just because the road bike has been refined over 100 years doesn't by any means imply that it is perfect, or at the end of its evolution.

New innovation--and verification of current market driven "innovation"--takes place only because people like Ben are going out and building test bikes like this. It also means to me as a customer that if I am buying one of his bikes that he has personally either tested himself or supervised the testing that means the features on his bikes really ARE innovative because they benefit me as a rider, not just because some marketing guru has decided that we need something new in order to justify selling more bikes.

BBD

[Wayne77]

Forgive my ignorance here...so I'm going to ask what might be a dumb question. I keep hearing talk of discs being too powerful/grabby/whatever, presenting an unsafe situation for less skilled riders who grab too much brake in a dicey situation. Shouldn't that be an easy problem to solve? Can't they be de-tuned somehow? use a smaller rotor? compounds that are less grabby?

Just wondering...I don't know much about disc tech, other than having XT hydros on my commuter and 29er and love 'em (I've used them in below freezxing temps for a few hours without issue too). Anyway - Thanks for educating me :-)

Personally, I think they are fugly on road bikes, but look great for the burly utilitarian look of mtb's, some all-road bikes, etc. They offend my aesthetic sensibilities, but then again this discussion isn't about aesthetics is it?

[redir]

A few years back I replaced the canti brakes on my mountain bike with V-brakes and that was quite an eyeopener in terms of performance. Then I got a new mountain bike with disk brakes... Wow. One little pull with the fragile end of a single digit and I was stopping on a dime. So I was thinking why in the world don't they put them on road bikes? After reading this article and several others on it I've turned back to thinking it's not such a great idea especially for myself at 6'4" 200lbs.

I guess the jury is still out. Like most things it's best to just wait and see what happens to it when it's in the wild for a while.

[pdmtong]

Haven't a lot of tandem riders been using discs for going on 10 years now?

certainly the issues with discs on road bikes would also appear in spades on tandems.

however, my guess is that they aren't to the fore of all the debate because
- discs on tandems will never be as ubiquitous as discs on cx or road
- the number of disc tandems in the real worlds is miniscule
- no captain with any kind of survival instinct is going to pilot his wife/stoker down 5 miles of 10% at 55mph.

I love going fast as much as anyone. But I also have to tell you that when my wife and I are letting the speed increase on our mtb tandem, the main thing on my mind is don't do anything that will lead to a crash. and I have 203/185 discs with 6-pistion calipers.

[GRAVELBIKE]

I commute almost daily on a disc-equipped Salsa Vaya (brakes are BB7, levers are Campag Centaur 10s). Tires range from 28mm to 32mm. I weigh 195, and the bike holds probably 10 pounds of gear. In rain and snow, the discs are an absolute godsend. In truly horrible weather, however, the brakes are not the limiting factor to remaining upright.

[jpw]

I commute almost daily on a disc-equipped Salsa Vaya (brakes are BB7, levers are Campag Centaur 10s). Tires range from 28mm to 32mm. I weigh 195, and the bike holds probably 10 pounds of gear. In rain and snow, the discs are an absolute godsend. In truly horrible weather, however, the brakes are not the limiting factor to remaining upright.

belt and braces, discs and studs.

[spiderman]

I think a disc option
Would help me solve problems
I have inherent with every day riding...
I have often thought at least a front disc
Would salvage the uniscasi for winter riding
Or an all conditions machine...
But the new design I find very, very attractive!

[Chance]

Forgive my ignorance here...so I'm going to ask what might be a dumb question. I keep hearing talk of discs being too powerful/grabby/whatever, presenting an unsafe situation for less skilled riders who grab too much brake in a dicey situation. Shouldn't that be an easy problem to solve? Can't they be de-tuned somehow? use a smaller rotor? compounds that are less grabby?
..............


See report below from one user. If brake can stop on a dime with one pull from a single finger, what comes next? Road bikes have relatively short front centers so they can flip over when pushed to the limit. With road calipers you have to pull pretty hard to do this (although it can still be done), but with some powerful discs it doesn't take much effort to stand a bike on its front wheel. More than that in a panic could lead to a beginner getting hurt badly. If the brake is detuned to make weaker, would people still like them as much? It's doubtful since much of what is reported is based on lots of stopping power. Also as noted below.

......Then I got a new mountain bike with disk brakes... Wow. One little pull with the fragile end of a single digit and I was stopping on a dime. ........

[oldpotatoe]

I don't think you can claim added maintenance for discs - takes me less time to swap pads on disc brakes than on my road bike.

Too much power? I have never heard any moto cat complain that his brembo's worked too well... Same thing for bikes- I never complained once about my magura gustavs having too much power (closest thing to a moto brake).

I will take disc brakes over anything else on long descents- less hand fatigue and less heat on the rim (which I think is a genuine concern on European style alpine roads- seen tubulars roll and seen an inner tube burst from too much heat).

:)

Have you seen a disc brake fade to the point of being gone on a long alpine descent? Cuz you will. They have not figured out the heat issue with road discs and that's why the wet road brakes weren't introduced at interbike by sram.

Plus teeny patch on a road bike tire. Grab a couple of fingers of wet disc brake and you are going to skid the tires..rear, not a big deal, front, big deal. YES, brakes CAN be too strong. The maguras I installed on a 115 pound girl's tri bike were way too strong. Comparing it to a 400 pound, many HP, plus or minus 'moto' rig makes no sense. Lotsa cooling cuz it doesn't have to be teeny, plus a wee bit more energy involved at 500+ pounds traveling at 90 MPH.

[HillDancer]

The disc brake system does not require hydraulic actuation to have superior modulation. Sufficient rotor mass to dissipate heat + appropriate pad + mechanical caliper + intelligent usage = no fade, and that's just with currently available components. If your cantilever brakes are weak, most likely you will adjust the straddle wire, change pads, or seek better mechanical leverage. The same approach to optimization applies to disc brakes, put forth a little intelligent effort, and reap rewards.

The tire is the limiting factor in available friction. One will not fly over the handlebars with some spastic grasp of the brake lever.

[Chance]

........

The tire is the limiting factor in available friction. One will not fly over the handlebars with some spastic grasp of the brake lever.

Will call BS on this. On dry pavement most road tires have enough grip that the front wheel will not skid before the bike will first lift the rear tire off the pavement, followed by rider flipping over the bars if he/she doesn't release brake instantly. It's easy enough to test and confirm. Sheldon Brown wrote about how to avoid this problem by practicing repeatedly to learn when bike was about to flip.

[spaced_ghost]

just go try to skid on your front tire on dry pavement without flipping the bike or at least lifting the rear wheel and see what happens. i mean, don't actually, because it won't work. and if it does, your front wheel will likely go sliding out from under you to the left or right and then you have the same result- face to pavement.

[Peter B]

certainly the issues with discs on road bikes would also appear in spades on tandems.

however, my guess is that they aren't to the fore of all the debate because
- discs on tandems will never be as ubiquitous as discs on cx or road
- the number of disc tandems in the real worlds is miniscule
- no captain with any kind of survival instinct is going to pilot his wife/stoker down 5 miles of 10% at 55mph.

I love going fast as much as anyone. But I also have to tell you that when my wife and I are letting the speed increase on our mtb tandem, the main thing on my mind is don't do anything that will lead to a crash. and I have 203/185 discs with 6-pistion calipers.

I think you hit a key point here WRT discs on tandems; rotor size. Most road/cross setups seem centered around 160/140 rotors which dissipate much less heat. Most tandems I've seen are only running a rear disc, again at 203 or greater.

Based on many responses in this thread discs can and do work for skilled folks on the road. But the prudent manufacturer knows that what they produce ends up on the floor of showrooms and anyone (of any skill, size or weight) can ride one out the door so long as they simply meet the minimum cost of entry. So the product has to be fairly well foolproof to minimize their liability. And the manufacturer's wisely feel that the current crop of road discs are not yet to that 'set and forget' level. Factor in the weightweenie mindset (always smaller & lighter) and in my mind they are clearly justified in their cautiousness.

[Kirk007]

If one can appreciate precise modulation and low lever effort when needed most, then absolutely yes. If one hasn't experienced superior braking performance beyond what one is using, then how can one speculate with certainty it wouldn't be useful?

Stating the obvious, climbing will inevitably lead to descents, it's not just one way going up. My descents usually have a technical component, blind corners, and always the possibility of unpredictable motorist behavior. I have 200mm rotors up front, 180mm in the rear, mechanical calipers with a great pad compound (SwissStop FTW), on my not-so-flyweight road bike. No fading behavior, or noise, or the other imagined drawbacks speculators claim. Two finger braking from the hoods, one finger from the drops. It's much easier for me to control braking at the threshold of lock-up by finessing one finger using disc brakes, than attempting to control multiple muscle groups when grasping a rim brake lever with clinched fist.

Calm now Hill Dancer. I have a roadish bike with mechanical discs that I use in Seattle wet; I've used powerful hyrdaulics on my downhill bike. But I've also dragged my ass up 20+ kilometer climbs all over the Alps, and plunged down the other side. For those rides I'll take a lighter bike and Campy sidepull brakes for the foreseeable future. I don't seem to have any trouble coordinating multiple muscles or suffering from clenched fist syndrome.

[FlashUNC]

Bike rumor had an enlightening post about cooking his brakes on a less than epic descent, and having to bail at a decent rate of speed.

It'll be ready for primetime at some point. But my fat butt may wait before making the plunge.

[Peter B]

Bike rumor had an enlightening post about cooking his brakes on a less than epic descent, and having to bail at a decent rate of speed.

It'll be ready for primetime at some point. But my fat butt may wait before making the plunge.

The cause was overheating and boiling off the fluid. Two key component ingredients: small, ultralight rotors and 1st gen Parabox brakes, particularly the small rear caliper and pads. Coupled with heavy application of braking on a steep descent and voila--no brakes! And it would seem he's not a beginning cyclist.

The majors are being careful releasing mass market road discs for good reason.

[HillDancer]

...On dry pavement most road tires have enough grip that the front wheel will not skid before the bike will first lift the rear tire off the pavement, followed by rider flipping over the bars if he/she doesn't release brake instantly...
Please share your personal experience with this type of braking event, and your personal experience using disc brakes on a road bike too.


just go try to skid on your front tire on dry pavement...your front wheel will likely go sliding out from under you to the left or right...
Bingo! That's why braking limits should be tested & practiced, to learn recovery technique and file away to become an implicit response later when needed.



I can do an intentional front wheel mini stoppie on my rim brake bikes as well as the road bike with disc brakes, so what.

These assertions that a person's innate sense of survival & avoidance of harm can't be trusted (except in the case of Bike Rumor's journalist), and brakes can be too good, are absurd.



Calm now Hill Dancer...I don't seem to have any trouble coordinating multiple muscles or suffering from clenched fist syndrome.
Good for you.
...It's much easier for me to control braking at the threshold of lock-up by finessing one finger...
And, I would put two 200mm rotors up front if I could.

[jpw]

I've been riding a Legend with front disc braking for the last three years and NEVER have I felt anything other than in complete control under braking in all conditions and most circumstances.

People who brake with discs and end up on the floor are not competent cyclists.
Become familiar with your equipment and learn good technique.

[tigoat]

A lot of fad for nothing!

ENVE already has a road disc fork and of course also a CX disc fork in the market for a while now. Calfee has sold a boat load of bikes with disc brakes for long time. Volagi was formed to sell disc equipped road bikes for a few years. Colnago is making a road race bike with disc brakes. Salsa just released a road bike with disc brakes. Foundry is also making a road bike with disc brakes. Specialized also is making a road bike with disc brakes. So is Lynskey. The list just goes on and on... So much for not jumping on the bandwagon! Who cares!

[BumbleBeeDave]

Will call BS on this. On dry pavement most road tires have enough grip that the front wheel will not skid before the bike will first lift the rear tire off the pavement, followed by rider flipping over the bars if he/she doesn't release brake instantly. It's easy enough to test and confirm. Sheldon Brown wrote about how to avoid this problem by practicing repeatedly to learn when bike was about to flip.

I've done it. First year I had my Serotta, did the MS ride and somebody cut in front of me and I grabbed both brakes and wasn't used to the new ones yet. I ended up doing a circus clown balancing act on the front wheel.

BBD

[shovelhd]

did the MS ride

That was your first mistake :)

[spaced_ghost]

Bingo! That's why braking limits should be tested & practiced, to learn recovery technique and file away to become an implicit response later when needed.



dont edit my post to make it fit your agenda. I said you would likely flip over first, and that your wheel WOULDN"T slide. FYI, i've seen a lot of flipping over headfirst wrecks in NYC from people with front brake only fixies trying to stop on a dime, I don't think people's "avoidance of harm" is quite as strong as you think. or actually, I think it is, but I think fear overrules practice and common sense.

[VA-Scooter]

It is hard to believe that serious cyclist are talking about the front brake flipping you over the handlebars. Yes it is possible-as are many other things if you do not pay attention & use your skills. I have disc brakes on my road bike & live in the mountains-I really like the brakes-Smooth,quiet & powerful. I do not think they are any better than top of the line road calipers but I think they are a real good choice if you like to run a variety of wider tires. I have used 700x25 road tires,700x33 CX tires & my favorite 700x32 Gran Bois Extra Leger. The combo of wider tires & disc really feel great on long fast descents. ATMO-I have ridden thousands of miles in the mountains on road disc & love them.

[lukasz]

dont edit my post to make it fit your agenda. I said you would likely flip over first, and that your wheel WOULDN"T slide. FYI, i've seen a lot of flipping over headfirst wrecks in NYC from people with front brake only fixies trying to stop on a dime, I don't think people's "avoidance of harm" is quite as strong as you think. or actually, I think it is, but I think fear overrules practice and common sense.

I've never seen someone go over the bars while trying to stop. You'd have to be quite a special person or, like a lot of NYC fairweather fixed-gear riders, have a non-setback post with the saddle set all the way forward for that "T-rex" look. You might go over the bars when most of your weight is teetering very close to them, I guess.

Discs can get pretty powerful, but the kind that are going on road bikes are comparable to sidepull rim brakes. Like I said before, the main advantage on a road bikes is not having to use cantis with fat tires.

[Mark McM]

I've never seen someone go over the bars while trying to stop.

Then you haven't been around enough cyclists for long enough. Due to the relatively high center of gravity and short front center of most bikes, it only takes about 0.5 - 0.6 g of deceleration to lift the rear wheel and send the bike end-over-end. With a good set of brake pads and hard squeeze of the lever, even an old single pivot side-pull brake can do this. (Note: the traction limit of bicycle tires on clean, dry pavement is near 1.0 g, so under straight line hard braking the bike will end-over before the front tire losses traction.)

[oldpotatoe]

I've never seen someone go over the bars while trying to stop. You'd have to be quite a special person or, like a lot of NYC fairweather fixed-gear riders, have a non-setback post with the saddle set all the way forward for that "T-rex" look. You might go over the bars when most of your weight is teetering very close to them, I guess.

Discs can get pretty powerful, but the kind that are going on road bikes are comparable to sidepull rim brakes. Like I said before, the main advantage on a road bikes is not having to use cantis with fat tires.

Not even close, no more comparable to wet discs on a MTB when compared to the MTB sidepull, called V Brakes. The mechanical advantage with effort required for a hydraulic brake and rotor is much higher than a side pull brake.

[Nooch]

I've never seen someone go over the bars while trying to stop. You'd have to be quite a special person or, like a lot of NYC fairweather fixed-gear riders, have a non-setback post with the saddle set all the way forward for that "T-rex" look. You might go over the bars when most of your weight is teetering very close to them, I guess.

Discs can get pretty powerful, but the kind that are going on road bikes are comparable to sidepull rim brakes. Like I said before, the main advantage on a road bikes is not having to use cantis with fat tires.

I had a customer pick up a roubaix last year -- sram apex. not the strongest brakes on the market. came back after a couple weeks, he'd wrecked when a car pulled out in front of him and he panic braked, pulled just the front with full force, went over the bars. I'm not sure if there was something else in play to help get the rear of the bike up (a pothole, maybe), but yeah -- an inexperienced cyclist in a panic situation can grab too much brake. It's these people that Serotta is worried about putting discs in their hands.

[shovelhd]

I broke my collarbone on a track bike with a front brake. I was training for districts on the road with it. I was going downhill approaching an intersection and the light changed quickly. I could not slow down fast enough through the pedals so I hit the brake. Up. Over. Down. Ouch. Walk home. Have the GF take me to the hospital.

[Kirk007]

And, I would put two 200mm rotors up front if I could.

Why? Please explain why you would do this?

I mean, it's apparent from your first four posts that you are a big fan of discs on road bikes. Fine, nothing wrong with that. I am too, on some road bikes. But postulating that those who question the application "haven't experienced the superior performance" and therefore no not of what they speak, calling others' positions absurd and then throwing up a relative absurd assertion given that you need dual rotors when you can already stop your bike with the discs you have with a single finger... well, the conversations here tend (or at least used to) to have a more congenial and nuanced tone than some other places on the 'net. Most of us don't do well with condescending smack right out of the box.

[TimD]

Let me offer a visual representation of my views on this subject :)

[Volant]

LOVE discs on my road bike, since 90% of spring riding is in the rain, and a lot of that is with long descents. I've never had an overheating problem as I don't ride-my-brakes. Those must be the same people I see smoking/glazing their brakes on their cars because they never give 'em a rest.

I've pulled the levers to the bar with my std. dura ace brakes and carbon hoops on a long wet descent, and that was actually scary as I couldn't scrub speed fast enough!

[spiderman]

i am back to wondering why is it do i think i even need brakes anyhooo...
:banana:
sorry...after phase 3 of our electronic medical record
my feel like ive been run over by a bike:bike:

[jbay]

certainly the issues with discs on road bikes would also appear in spades on tandems.

however, my guess is that they aren't to the fore of all the debate because
- discs on tandems will never be as ubiquitous as discs on cx or road
- the number of disc tandems in the real worlds is miniscule
- no captain with any kind of survival instinct is going to pilot his wife/stoker down 5 miles of 10% at 55mph.

I love going fast as much as anyone. But I also have to tell you that when my wife and I are letting the speed increase on our mtb tandem, the main thing on my mind is don't do anything that will lead to a crash. and I have 203/185 discs with 6-pistion calipers.FWIW, the majority of the tandem models (http://www.co-motion.com/index.php/tandems/models/all_tandems) offered by Co-Motion these days have disk brakes. Only their lightest, most race-oriented models have rim brakes.

For my/our own part, we got disks on our tandem because we like to ride lots of dirt and gravel roads which require fat tyres and to do so in all kinds of conditions. The obvious rim-brake alternatives that work well with those fat tyres have their own issues (pad-dive with cantilevers and pad-rise/tyre sidewall slashing with centrepulls) when doing lots of descending in bad conditions. Add to that the possibility of needing to replace rims after just one ride (think Green Mountain Double in the rain) or a couple of wet weeks in the Alps, and disks start to seem very attractive - in my book, at least. The immediate braking response in the wet is not to be sniffed at either, while I'm almost ashamed to say how much I appreciate the lack of filth when fixing a puncture on a wet day.

We have toured loaded in the Pyrenees on its predecessor (with a disk on the front only) and bombed descents all over New England on this one and have felt very comforable doing so. However, I would also agree with other commenters that I would consider disks more appropriate for technically savvy riders and competent descenders and less suitable for beginners. Mind you, I would almost say the same about cantilevers...

-- John


https://lh6.googleusercontent.com/-_NjFzeB3pWU/T8aMGdScCkI/AAAAAAAAEjU/fPuglkz9TiM/s1784/DSC01611.jpg

[nahtnoj]

Let me offer a visual representation of my views on this subject :)

Installing a fork with a ~390 A/C height on a bike designed around ~365 is a fantastically bad idea. Have you noticed how poorly your bike handles while descending at high speed in the rain?

I have two words - ceramic rims.

[pdmtong]

FWIW, the majority of the tandem models (http://www.co-motion.com/index.php/tandems/models/all_tandems) offered by Co-Motion these days have disk brakes. Only their lightest, most race-oriented models have rim brakes.

For my/our own part, we got disks on our tandem because we like to ride lots of dirt and gravel roads which require fat tyres and to do so in all kinds of conditions. The obvious rim-brake alternatives that work well with those fat tyres have their own issues (pad-dive with cantilevers and pad-rise/tyre sidewall slashing with centrepulls) when doing lots of descending in bad conditions. Add to that the possibility of needing to replace rims after just one ride (think Green Mountain Double in the rain) or a couple of wet weeks in the Alps, and disks start to seem very attractive - in my book, at least. The immediate braking response in the wet is not to be sniffed at either, while I'm almost ashamed to say how much I appreciate the lack of filth when fixing a puncture on a wet day.

We have toured loaded in the Pyrenees on its predecessor (with a disk on the front only) and bombed descents all over New England on this one and have felt very comforable doing so. However, I would also agree with other commenters that I would consider disks more appropriate for technically savvy riders and competent descenders and less suitable for beginners. Mind you, I would almost say the same about cantilevers...

-- John


I completely understand and agree with your point, If I could ever get my wife off dirt and onto pavement I would buy a co-motion disc tandem in an instant.

my postulation though was with all the discussion about disc road, why has this never come up regarding disc road tandem?

a road tandem has more weight both bike and riders than any single road bike. fork is beefier, rear stays too. but perhaps not by THAT much. so why not the same concern about fade etc. for tandems?

[Peter B]

I think most disc-equipped tandems, at least the one's I've seen, are running mechanical setups and run significantly larger rotors than what I see on single bikes. With mechanical calipers there's no fluid to boil off and with larger rotors there's more surface area for both braking power and heat dissipation.

[pdmtong]

I think most disc-equipped tandems, at least the one's I've seen, are running mechanical setups and run significantly larger rotors than what I see on single bikes. With mechanical calipers there's no fluid to boil off and with larger rotors there's more surface area for both braking power and heat dissipation.

peter...I think you nailed it. yes, its avids and generally 185/160 oh duh on my end

as noted my ventana has 203/185....when my wife and I are pitching down some section that is so steep she can see over my shoulders and over the front wheel no problem, it is quite reassuring that with one finger I can stop. as you kow, tandem wheelbase so long endo not possible. so the stopping (and front tire traction) become the issue. I run a 2.4 in front. that seems to be the balance between being just a pig and hassle to pedal, and not worring about washing out

[zap]

Tandem rider for years. Newest tandem has bb7 discs that I never cared for until I swapped avid disc rotors for Shimano ice. Fade with avid roundagon and g3 was a problem even on short descents were I would slam on the brakes at the bottom. Then the avid discs would get bent out of shape and make stupid noise until they cooled about 2 miles later.

Thankfully the Shimano ICE discs solved that nonsense. Runs cooler even after 10 mile descents with a few twist and turns.

The main reason for our desire to have discs on the tandem is to eliminate inner tube blowouts. Foul weather too.

Yes, wife and I have speed past rv's on blue ridge parkway in NC......something north of 55mph. That was on our first tandem (which we still have) with Avid TriAlign canti brakes.

[Peter B]

<Snip>

The main reason for our desire to have discs on the tandem is to eliminate inner tube blowouts.

I rode a 2-tandem team on FC508 in 2009. Captain of the other tandem had a front tube blow on the nighttime descent down Towne's pass at >55mph. He hauled it to a stop and kept it upright, much to the stoker's delight.

Two years later Smead and I overcooked his rear wheel coming down Howell Mtn into Pope Valley on the Knoxville Double. Realized later we'd partially melted the rim tape, but not before flatting 6 more times during the ride, including one at speed coming down Cobb Mtn. He kept us off the pavement and out of oncoming traffic. The rear rim didn't fare as well. Still, after bending and filing the sidewalls true and begging another tire we managed to limp to the finish some 40 miles on.

Both events were cause for major pucker factor and motivate serious consideration of discs. Smead did subsequently fit a large rear rotor and BB7 caliper. We rode it again on a speedy 200k last month and the added power and shift in heat concentration were welcome.

But for a tandem, again, I recommend large rotors.

[pdmtong]

I put an avid 203 on the front end of our first ventana tandem. it worked ok. better than v-brakes for sure. our second venyana is the one with hope mono ti 6-piston caliper on the 203 rotor up front.

NO COMPARISON.

for dirt, hydraulics are the only way to go. needed because more demand for immediate speed modulation.

for pavement, I can see the avid would be good enough - have you tried the the avid solid housing conduit for the front brake?

[Chance]

Then you haven't been around enough cyclists for long enough. Due to the relatively high center of gravity and short front center of most bikes, it only takes about 0.5 - 0.6 g of deceleration to lift the rear wheel and send the bike end-over-end. With a good set of brake pads and hard squeeze of the lever, even an old single pivot side-pull brake can do this. (Note: the traction limit of bicycle tires on clean, dry pavement is near 1.0 g, so under straight line hard braking the bike will end-over before the front tire losses traction.)

Thank you.

It can not only happen easily in theory as you've pointed out, it happens in practice too. Doing max braking drills to get a feel for maximum available deceleration also confirms it.

[jpw]

Installing a fork with a ~390 A/C height on a bike designed around ~365 is a fantastically bad idea. Have you noticed how poorly your bike handles while descending at high speed in the rain?

I have two words - ceramic rims.

who is still making worthy (no flaking or pitting please) ceramic rims?

I had a wheelset with Mavic ceramic rims (T520s). The braking surface of the front rim remains in perfect condition, but the rear rim's braking surface flaked and pitted very badly. I stopped using it.

I like ceramic rims, when they're made right. They have a definite advantage in the wet over alu. Better than carbon I can imagine, but not as good as discs.

[jpw]

Let me offer a visual representation of my views on this subject :)

Wow.

Wouldn't you be better off with one of these?;

http://www.enve.com/forks/road-disc.aspx

367 span, 28mm tire.

It only has a 35 cm steerer tube and 4 cm max stack height though.

[Chance]

Why? Please explain why you would do this?

I mean, it's apparent from your first four posts that you are a big fan of discs on road bikes. Fine, nothing wrong with that. I am too, on some road bikes. But postulating that those who question the application "haven't experienced the superior performance" and therefore no not of what they speak, calling others' positions absurd and then throwing up a relative absurd assertion given that you need dual rotors when you can already stop your bike with the discs you have with a single finger... well, the conversations here tend (or at least used to) to have a more congenial and nuanced tone than some other places on the 'net. Most of us don't do well with condescending smack right out of the box.

Agree his tone is way too aggresive and condescending to deserve a reply. Personally would have not corrected him in the first place if it didn't involve safety. That's where we should all draw the line. If something/idea/concept or whatever is suggested that could get a fellow rider hurt we should point it out.

By the way, there are a lot of misunderstandings about the physics of bike braking limits. Being able to flip over the bars (due to rider error) is pretty much accepted common knowledge. No more need to beat it to death.

Notice on this thread that someone :rolleyes: brought up the disc mass as a means to keep them cool. While that may work initially to slow heat buildup, in very long descends the discs will approach steady state temperature. Heat capacity at that point doesn't help. The solution of course has been to make the disc larger in diameter in order to dissipate more heat (as in to transfer heat to surrounding air), but that can make them even more powerful if the same caliper is used. They get heavier too.

Second misunderstanding is that braking with both front and rear wheels at same time will prevent a bike from flipping over in a panic stop taken to an extreme. Not so. As the rider applies brakes harder and harder the total weight will shift forward into it is mostly over the front tire, making the rear tire lock up and skidding first, followed by it lifting and bike flipping over. Please don't read into this that somehow this suggest we shouldn't use the rear brake. Not saying that. Just that using the rear brake in combination with the front doesn't prevent a (single) bike from going over.

The greatest one mentioned here is about human behavior in panic conditions. Apparently some here are too young to remember what "typical" drivers did with car brakes before ABS, right? Before ABS, most panic stops ended up with driver locking up the tires and skidding. Experienced drivers may have known to avoid this because it actually lengthens the stop, but when faced with a wreck even most experienced drivers added more brake until the skid occurred. This is the kind of "typical" human reaction some manufacturers may be worried about. There is a difference between what we know we should do and what we actually do under panic conditions. Not all, but some.

[TimD]

Bike rumor had an enlightening post about cooking his brakes on a less than epic descent, and having to bail at a decent rate of speed.


The cluelessness demonstrated by the rider and the author of that article was more than epic.

[TimD]

Installing a fork with a ~390 A/C height on a bike designed around ~365 is a fantastically bad idea. Have you noticed how poorly your bike handles while descending at high speed in the rain?


Have you ridden my bike, Dr. Frist? No, you haven't.

[TimD]

Wow.

Wouldn't you be better off with one of these?;

http://www.enve.com/forks/road-disc.aspx

367 span, 28mm tire.

It only has a 35 cm steerer tube and 4 cm max stack height though.

I'm using about 325 mm of steerer. This is a winter bike and I'm interested in less saddle-bar drop over the winter.

Yes, the Enve fork would be a better technical choice. I looked at it. It is more than double the price of the Tange Prestige. I wasn't willing to pay the difference given the purpose of this bike and the amount of use it gets.

[zap]

But for a tandem, again, I recommend large rotors.

Agreed, we have 203 front and rear. But here again, based on my testing, regular one piece steel rotors are insufficient for fast tandem teams that ride in hills, much less mountains.

I'm also looking for new mechanical calipers for our S&S travel tandem. I think it's TRP that should have one out soon. Avid BB7 is such a basic design that it makes optimal setup with the best rotors difficult.

I'm of the opinion that fast road singles should have 165 for lighter riders and 185 for everyone else up front. Braking forces on roads is much higher than on dirt.

[jpw]

I'm using about 325 mm of steerer. This is a winter bike and I'm interested in less saddle-bar drop over the winter.

Yes, the Enve fork would be a better technical choice. I looked at it. It is more than double the price of the Tange Prestige. I wasn't willing to pay the difference given the purpose of this bike and the amount of use it gets.

what's the span of the Tange fork?

[jbay]

I have two words - ceramic rims.Been there, done that, burned the t-shirt.

On the tandem again, we had a piece of ceramic flake off the sidewall after hitting a pothole on a rough descent. We didn't get a pinch-flat or, to put it another way, we didn't hit anything that hard. However, the missing piece of ceramic rendered that brake unusable - and this was on day one of a two week loaded tour...

On another occasion, we also managed to completely melt the brake pads in one solitary hard stop, when a road was blocked on a descent. That also happened in the middle of a trip, but we were carrying spare pads so we were able to continue. However, I switched back to regular rims ASAP after returning from that trip.

All the above was with Sun ceramic rims, BTW.

-- John

[jbay]

Tandem rider for years. Newest tandem has bb7 discs that I never cared for until I swapped avid disc rotors for Shimano ice. Fade with avid roundagon and g3 was a problem even on short descents were I would slam on the brakes at the bottom. Then the avid discs would get bent out of shape and make stupid noise until they cooled about 2 miles later.

Thankfully the Shimano ICE discs solved that nonsense. Runs cooler even after 10 mile descents with a few twist and turns.I'm not trying to scare you when I write this, but there was an account in an English cycling magazine about a tandem couple melting the aluminium portion of an IceTech rotor. I suspect they dragged the brakes down a 33% descent in the Lake District but, even so, just bear it in mind.

-- John

[svelocity]

I'm not trying to scare you when I write this, but there was an account in an English cycling magazine about a tandem couple melting the aluminium portion of an IceTech rotor. I suspect they dragged the brakes down a 33% descent in the Lake District but, even so, just bear it in mind.

-- John

How about some carbon rotors? According to their literature they don't heat up like metal ones...

http://kettlecycles.com/

[rice rocket]

How about some carbon rotors? According to their literature they don't heat up like metal ones...

http://kettlecycles.com/

Physics-defying rotors?!

[jbay]

How about some carbon rotors? According to their literature they don't heat up like metal ones...

http://kettlecycles.com/John Ferguson posted his first impressions of them here (http://ridingthecatskills.com/2013/03/14/kettle-cycles-sfl-siccc-rotors-first-rides/). The idea is intriguing, but I won't be beta-testing them on the tandem.

-- John

[HillDancer]

...Notice on this thread that someone :rolleyes: brought up the disc mass as a means to keep them cool. While that may work initially to slow heat buildup, in very long descends the discs will approach steady state temperature. Heat capacity at that point doesn't help. The solution of course has been to make the disc larger in diameter in order to dissipate more heat (as in to transfer heat to surrounding air), but that can make them even more powerful if the same caliper is used. They get heavier too...
Criticisms of disc brake weight, and power, are valid for those with different cycling priorities than mine. When I need to stop or slowdown, I want to stop or slowdown very badly, and at that time of need it matters not the weight nor aesthetic of the braking system.

Excessive high thermal stasis is a non-issue with large steel rotors for most but a few outliers, it's one of the best reasons to use them. This is not a bad thing.

Larger rotors provide less lever effort for the same work. Another, this is not a bad thing.

Another benefit of large steel rotors for paved riding is improved modulation. The aspect of modulation most important to me is the ability to predictably hold the brakes at the threshold of lock-up. Note these reports of endos are on rim brake bikes. There's guess work involved when gripping hard with rim brakes; will they be forgiving or will they lock? Once the wheel is locked all the work is done, the ability to lock the wheel is not a valid criteria for evaluating a brake system. Of course there will be the usual idiosyncratic objections; can't avoid that.

My reality testing, for 170,000 feet of elevation gain (short & steep climbs, no mountains) spanning a 10 month period, I experimented with Avid steel rotor sizes 140-160-180-200mm, brake pads of hard and soft ceramic, Avid Metallic and organic, and SwissStop multiple compound green pads. The pad experiments also involved pairings of different pads inboard & outboard. The bottom line of the results: for the short, steep, high speed, technical descents these rotors & pads were used on, 200mm front & 180mm rear sizes provided the best performance, no pad glazing, no rotor distortion, and no heat induced fade. The 140mm rotor mounted on the rear failed on all counts quickly, the 160s mounted on the front and/or rear also failed to be problem free over time. SwissStop green pads offered the most consistent modulation in dry weather, with low noise as an added bonus. Each of the pads and parings had their good & bad side.

The current technology of bicycle disc braking systems is gaining ground on addressing weight & heat concerns. As mentioned above, carbon based disc brake rotors for bicycles are available and will be improved upon, carbon based pads for bicycles are in the development phase and have great promise. We already rely on these technologies when modern large passenger jets land.

[jpw]

So, what is being "censored" in Ben's blog post? Electromagnetic braking?

[zap]

I'm not trying to scare you when I write this, but there was an account in an English cycling magazine about a tandem couple melting the aluminium portion of an IceTech rotor. I suspect they dragged the brakes down a 33% descent in the Lake District but, even so, just bear it in mind.

-- John

I'm aware of the potential issue. It was reported that Tour magazine melted an icetech disc. I guess if a team is heavy enough and drags a brake.......

[Peter B]

<snip>

My reality testing, for 170,000 feet of elevation gain (short & steep climbs, no mountains) spanning a 10 month period, I experimented with Avid steel rotor sizes 140-160-180-200mm, brake pads of hard and soft ceramic, Avid Metallic and organic, and SwissStop multiple compound green pads. The pad experiments also involved pairings of different pads inboard & outboard. The bottom line of the results: for the short, steep, high speed, technical descents these rotors & pads were used on, 200mm front & 180mm rear sizes provided the best performance, no pad glazing, no rotor distortion, and no heat induced fade. The 140mm rotor mounted on the rear failed on all counts quickly, the 160s mounted on the front and/or rear also failed to be problem free over time. SwissStop green pads offered the most consistent modulation in dry weather, with low noise as an added bonus. Each of the pads and parings had their good & bad side.



What is your height and weight so that we have some additional context within which to understand your objective testing and experience/results?

[Lazer]

This bike is comically ugly. As someone said, it looks worse than '90's tribal arm band tattoo. Hope Serotta's new blood realize they are out of touch and over-priced. Can we get that headtube any taller/higher? I don't want to use a +17 stem. pfffffffft.

[zap]

This bike is comically ugly. As someone said, it looks worse than '90's tribal arm band tattoo. Hope Serotta's new blood realize they are out of touch and over-priced. Can we get that headtube any taller/higher? I don't want to use a +17 stem. pfffffffft.

psssssst :rolleyes:

[HillDancer]

What is your height and weight...
5'8" 185lb

[jpw]

is the prototype bike 130mm or 135mm in the rear axle?