Disc brakes and road bikes -- any insight... [Archive]

Joellogicman

10-21-2009, 05:52 PM

probably better than most alternatives in the slop and wet. They can over heat. Discs will warp and require turning if not replacement. Disc pads seem to last longer than rim brake pads.

I don't see how discs, especially hydraulic, can ever be lighter than modern rim brakes. Even mechanical have a lot of extra parts and require additional braze ons.

Here is a picture of my former disc brake road bike. I gave it away recently as a result of frustration with the Rohloff. The disc brakes were great, although I had to turn them twice in two years.

http://www.oswaldcycleworks.com/mjolwhole.jpg

quattro

10-21-2009, 05:59 PM

http://forums.roadbikereview.com/showthread.php?t=190708
Here you go, everything you always wanted to know about disc brake road bikes, enjoy.

weaponsgrade

10-21-2009, 07:14 PM

Leiphiemer has a Landshark built road bike with disc brakes. Should be pics somewhere on the Landshark site.

xjoex

10-21-2009, 08:03 PM

I have disc brakes on my cross bike and mountain bike. Simply put they are the jam. I have never had to turn my rotors. I have had a rock smash into one on my mountain bike, but never from heat have they warped.

I used to use hydraulic brakes, but switched to Avid bb7. My next road bike will have discs too. They just make too much sense.

-Joe

nahtnoj

10-21-2009, 08:14 PM

http://forums.roadbikereview.com/showthread.php?t=190708
Here you go, everything you always wanted to know about disc brake road bikes, enjoy.

Not to act like one of those elitist dicks from across the hall, but that isn't across the hall...

:D

Joellogicman

10-21-2009, 08:44 PM

but switched to Avid bb7.

I just was not as lucky. I don't see it as a problem. Things go wrong with rim and drum brakes too.

My next road bike will have discs too. They just make too much sense.

I liked the discs on the Oswald. The Rohloff was my issue. I am having a new light tourer - every day bike built for me. It will have discs.

Joellogicman

10-21-2009, 08:45 PM

Not to act like one of those elitist dicks from across the hall, but that isn't across the hall...

:D

I guess I have to ask. I have been posting here for while but have not a clue where you all mean by across the hall.

paczki

10-21-2009, 08:52 PM

I guess I have to ask. I have been posting here for while but have not a clue where you all mean by across the hall.

Velocipede Salon

Why didn't you like the Rohloff? Got sick of the 7 to 14 jump?

Dekonick

10-21-2009, 08:53 PM

www.velocipedesalon.com = across the hall

Joellogicman

10-21-2009, 09:17 PM

Velocipede Salon

Why didn't you like the Rohloff? Got sick of the 7 to 14 jump?

I had maintenance issues and no one - leastways in Chicago - (and certainly not me) could figure out how to properly address them.

Last straw was this summer. A seal broke and most of the oil leaked out. Rohloff voids the warranty if you do not use theirs. Turns out Rohloff pulled its U.S. distributor and my LBS could not get any replacement oil for two months.

In any event, there must have been some disconnect between my Serotta fitter and Oswald as I could never get comfortable on the bike. One of the LBS mechanics liked it so I let him have it.

Joellogicman

10-21-2009, 09:19 PM

www.velocipedesalon.com = across the hall

Now I know a new place to spend way too much of my off the bike time!

Louis

10-21-2009, 09:28 PM

They just make too much sense.

For me the big disk (rim) makes more sense if you're talking efficiency of load paths.

paczki

10-21-2009, 09:31 PM

For me the big disk (rim) makes more sense if you're talking efficiency of load paths.

Not in the wet and muddy. I love disc brakes!

rudetay

10-22-2009, 08:25 AM

I have a front disk on my road/cross bike:

http://velospace.org/files/Steelman_change_1.jpg

It's great for trails and cross, but riding in dry weather there isn't much advantage. The modulation and brake feel is great though.

The pads do last impressively longer than normal rim pads, and if you ride in really grimy conditions they'll save you from wearing through your rims.

If disk brakes on road bikes take off I could also see a wave of ultra light weight disk specific rims, as there is no need for a braking surface and less material can be used. On MTB rims this difference can be pretty large ~100g between Stans disk brake specific race rims and standard rim brake rims. Looking at my BB7 roads I could also see how these things could be lightened up A LOT, they weigh a ton, but it seems like all the weight is in the shell. In a road specific environment I imagine they could cut this down to a minimum and get it very low, even using traditional materials.

Disks also allow a lot more flexibility in wheel/tire size. For your road bike you could have a go fast 700c wheel set with 28c tires, and then a comfort set for the towpath in 650b and larger tires, no adjustment of the brake necessary. Note that I don't say 23c tires, you're not going to get much advantage of the increased power without some slightly larger rubber. I found my 33mm tires to be great.

sashae

10-22-2009, 08:30 AM

Here is a picture of my former disc brake road bike. I gave it away recently as a result of frustration with the Rohloff. The disc brakes were great, although I had to turn them twice in two years.

http://www.oswaldcycleworks.com/mjolwhole.jpg

Joe, sorry to hear you had issues with your Rohloff bike! I actually had a Co-Motion built that was partially inspired by your Oswald, using discs and a Rohloff. I actually love mine... I've got two Rohloffs now, and have fortunately not experienced any issues.

As for discs, I've got hydraulics on a cargo bike, and Avid BB7 mechanicals on my Co-Motion. The hydros are VASTLY stronger, but the mechs have been great. On a couple of rainy rides with friends, I found them to stop much better than their rim brakes, and had generally good experiences with them. I would certainly go with discs again.

http://farm3.static.flickr.com/2478/3657043990_9dceb585bf_b.jpg

http://farm4.static.flickr.com/3616/3657040438_83bcdf78c1_b.jpg

RPS

10-22-2009, 09:18 AM

UCI at one time banned disc brakes on pro road racing bikes. I recall reading they had safety concerns but who knows what they really wanted.

IMO it�s hard for new technologies to be adopted by the masses unless racers are using them. Disc brakes may be a different case because they were first proven in MTB applications.

DfCas

10-22-2009, 09:39 AM

Disc brakes require a sturdier fork, degrading the ride quality of a rigid fork. I woud also be afraid of a low spoke count wheel under the forces a front brake can generate on a dry surface.

I had a commuter/cross bike with Mavic Speed City wheels/disc brakes, and under heavy braking the rim would flex to the left at the top of the arch by 15mm or so. It was scary to watch.

I've had disc brakes on my mtb since 2001, and belive that is a great application for them, along with the 3 tandems we had. A commuter is also a good place, but for a lighweight, quick roadbike , I think they cause more problems than they solve. Heavier hubs, heavier wheels,heavier brakes, and degraded ride quality from the fork are deal breakers for me.

For those that say the rim brake is a larger disc brake, you are leaving out the actuation ratio of the rim brake pads compared to the disc brake pads. Disc brake pads have a much higher leverage ratio, compensating for the reduced rotor size. Both work well in the dry, but the disc works well in rain, snow, and I have never had icing issues with disc brakes. I have had ice on the rims.

Joellogicman

10-22-2009, 09:46 AM

Joe, sorry to hear you had issues with your Rohloff bike! I actually had a Co-Motion built that was partially inspired by your Oswald, using discs and a Rohloff. I actually love mine... I've got two Rohloffs now, and have fortunately not experienced any issues.

I am not completely turned off on Rohloffs.

The current U.S. distributor situation is a problem. One hopes Rohloff gets a new U.S. distributor in place soon if they have not already.

I live in a condominium with limited space for the bikes I use. I could not justify keeping a bike with an open ended service issue.

Joellogicman

10-22-2009, 09:47 AM

sashae

10-22-2009, 10:07 AM

I live in a condominium with limited space for the bikes I use. I could not justify keeping a bike with an open ended service issue.

I got my hub serviced at Rohloff US once (to convert from non-disc to disc) but have mainly been dealing with SJS Cycles in the UK for service parts. It's a hell of a lot easier than waiting for Rohloff US to get them ;)

konstantkarma

10-22-2009, 10:13 AM

Not to act like one of those elitist dicks from across the hall, but that isn't across the hall... :D

Nope THAT'S the wrong side of the tracks....the Dark Side of the hall, if you catch my drift. :cool:

Acotts

10-22-2009, 10:13 AM

I think they make a ton of sense on a CX bike. For sure, they will be on my next CX bike. Disk brakes are the biz. Canti are the suck.

dd74

10-22-2009, 11:37 AM

Yeah, maybe I can see them more on a CX bike or a road bike with more relaxed dimensions; something to ride in inclement weather - which we do get in this so-called (ahem) paradise. :rolleyes:

Tobias

10-22-2009, 05:04 PM

For me the big disk (rim) makes more sense if you're talking efficiency of load paths.
+1

Makes most sense to me for a performance road bike. It's hard to beat the simplicity and lower weight of a rim brake. Costs are relatively low too. About the only down side for me is rim wear and that's not enough of an issue to justify going to discs. Stopping power hasn't been an issue since the introduction of dual pivot calipers and V brakes.

dawgie

10-23-2009, 09:18 AM

dogdriver

10-23-2009, 09:27 AM

Sweet bike, Sashae...

salem

10-24-2009, 08:06 AM

I was happy to see I'm not the only one running a disk in front and cantis out back, although mine is a mountain bike. This makes a lot of sense for me, with the lighter brake setup in back, and the disk in front where physics of weight transfer (the harder you brake, the more weight, but not mass, there is on the front tire) allows for the greatest stopping power.

Of note, I am using a cable disk on front, v-style long cable pull levers for both, and cantis in back with a super short straddle cable to correct for the lever/cable pull geometry. Regarding that last bit, one thing I love about canti brakes in that you can tune the feel and power by adjusting the straddle cable length.

But getting back to the front of the bike (no pun intended, really), the aspect of disks that I like but rarely see mentioned is consistency. I'm around 140 pounds and can lock up just about any type of brake, so power isn't so much and issue, but with the generally cleaner rotor (vs. a rim) and the hard, abrasive disk pads (that would eat through an aluminum rim in no time), the braking from disks is very consistent from application to application and around the full rotation of the wheel. This allows me a to brake harder without a lock up when the pads grab more at some time or place along the rim.

That said, out of all my bikes (enough that I don't know the count), I have only half of one with disks. For the rest, weight, simplicity, and price win the day.

Tobias

10-24-2009, 02:16 PM

Of note, I am using a cable disk on front, v-style long cable pull levers for both, and cantis in back with a super short straddle cable to correct for the lever/cable pull geometry. Regarding that last bit, one thing I love about canti brakes in that you can tune the feel and power by adjusting the straddle cable length.
Doesn't this depend largely on type of canti used?

tuscanyswe

10-24-2009, 02:40 PM

I haven't used disc brakes but have cantilever brakes on my commuter/touring bike. Canti brakes provide more stopping power than caliper brakes and have some distinct advantages over discs. Wheels with disc brakes are not compatible with other bikes with caliper or canti brakes, so you can't swap wheels. Disc brake wheels are also more expensive. It can be hard finding a rack to fit on bikes with disc brakes.

The main advantages to disc brakes are that they provide better stopping power in wet condition and with heavy loads. Canti brakes are nearly as good in that regard, and much simpler technology and less expensive. You don't need an extra stout fork with canti brakes, so your bike will ride better.

If live somewhere like the NW where it rains all the time, then disc brakes might be a good option. Otherwise, I would opt for cantis if you want more stopping power and/or room for larger tires.

I keep hearing ppl say that. Cantis provide more stopping power than road calipers.. When where what cantis are you all using??? Ive never felt that road calipers were lacking stopping power. Not even the Zero gravitys i have that are definetly weaker than record for example, however every canti bike ive had seem to be so bad i consider them dangerous in traffic.

For a non racing cross bike or touringbike i think discs are the only way to go. For roadbikes i fail to c the point since ive never had issues with calipers.

Marcusaurelius

10-24-2009, 05:13 PM

I've had disc brakes on a cyclocross for some time now and they work great in the wet stuff. The cantilevers on my touring bike work fine but after going through a large puddle there's definite momentary loss of stopping power.

Also rim brakes wear out rims quickly in the monsoon conditions that last all winter here.

I've never had problem with ride quality with the front fork which happens to be carbon. It's stout and smooth. I've riden other bikes with disc brakes and steel fork and the ride was just as good as non disc fork.

I would say I see more and more disc brakes on hybrid 700c commuters in fact I'd say it's rare not to see disc brakes on city bikes.

At some point soon I will switch to 700x25c tires on the red demon. I will also add fenders and maybe a rear rack.

salem

10-24-2009, 06:44 PM

Doesn't this [straddle cable length] depend largely on type of canti used?
The brake design, as well as the distance (width) between the posts will affect what straddle cable length you want, but regardless of the brake, varying the straddle length will affect the brake feel and power. Aside from speed and ease of assembly for a bike shop, it is a shame to use the new splitter style straddles and give up this tuning ability.

djg21

10-24-2009, 07:17 PM

I always wondered what disc brakes are like on road bikes. Are they more powerful than standard brakes? Lighter? Easier to maintain?

And if anyone has any photos of a disc brake setup on a road bike, please post them if possible.

Thx.

Why? They are heavy, ad to the rotating mass of the wheel, and unecessary unless you're on a tandem or weigh a lot and ride downhill exclusively. If you want to stop in the wet, get a good brakeset, some ceramic rims and good pads .

IMO, discs would be dangerous in a pack situation where you need a light touch and the ability to modulate to trim speed while staying smooth.

On edit -- the OP was asking about road use, and not use on a CX bike, or on trails, etc.

paczki

10-24-2009, 08:00 PM

Why? They are heavy, ad to the rotating mass of the wheel, and unecessary unless you're on a tandem or weigh a lot and ride downhill exclusively. If you want to stop in the wet, get a good brakeset, some ceramic rims and good pads .

IMO, discs would be dangerous in a pack situation where you need a light touch and the ability to modulate to trim speed while staying smooth.

On edit -- the OP was asking about road use, and not use on a CX bike, or on trails, etc.

They rotors add mass in the middle of the wheel, meaning less of a problem than the rim, and they are light. Most of the mass is the brake itself, which is not on the wheel.

As to braking in a pack, it's all how you set them up. My disc brakes modulate very well and I don't set them too tight.

I have very good rim brakesets with good pads, and they don't compare to discs in the wet.

rugbysecondrow

09-07-2010, 08:53 PM

I am reviving this due to a recent project I have coming up. I sent in my deposit for a new Bedford today and I am looking for something a little different. It will be a fat tire'd SS, road disc bike. I am thinking Paragon Sliding drops to accomodate any alignment issues with the disc/braking mechanism. I like the idea of the road disc brakes and it sounds like most people who actually use them are happy with them, with most of the nay-sayers being folks who have not.

I am thinking Avid BB7 road brakes? Anybody have any insight into wheels? I am just thinking 29er wheels since they are strong, disc compatible and take wider tires well.

Is there anything to add to this discussion from those who use these brakes? Any road disc experiences in general aside from what has been expressed?

Thanks

firerescuefin

09-07-2010, 09:05 PM

Rugby,

http://velonews.competitor.com/2010/09/news/eurobike-report-more-cyclocross-bikes-from-across-the-pond-including-hankas-disc-brake-equipped-stevens_139068/attachment/eb2010_across_round2_22

New Stevens Cross bike w/discs as seen on the front page of Velonews today....says their using Shimano discs. May be of interest, although different application

oldpotatoe

09-08-2010, 08:10 AM

I always wondered what disc brakes are like on road bikes. Are they more powerful than standard brakes? Lighter? Easier to maintain?

And if anyone has any photos of a disc brake setup on a road bike, please post them if possible.

Thx.

Good for tandems and cross. Heavier, more expensive, more complicated, requires a different rear triangle and fork for a standard 'enthusiast's' racy type bike. An answer to a not asked question for a road bike that isn't ridden in the wet/mud/rocks. Dual pivot brakes rubbing on a bicycle rim works so well, is so simple, can be so cheap and still be effective.

xjoex

09-08-2010, 08:27 AM

...

I am thinking Avid BB7 road brakes? Anybody have any insight into wheels? I am just thinking 29er wheels since they are strong, disc compatible and take wider tires well.

Is there anything to add to this discussion from those who use these brakes? Any road disc experiences in general aside from what has been expressed?

Thanks

I built wheels for my bike, I bought XTR centerlock hubs and laced them to open pros. I ride it a ton and have never knocked the wheels out of true.

http://i62.photobucket.com/albums/h85/boulderjoe/bikes/100_0565-1.jpg

I am riding BB7 roads with Ultegra STI levers.

-Joe

Lurch

09-08-2010, 03:13 PM

I am thinking Avid BB7 road brakes? Anybody have any insight into wheels? I am just thinking 29er wheels since they are strong, disc compatible and take wider tires well.

Thanks

Like Joe, running Avid BB7s with Ultegra STI's. Targeted a bit beefier wheels since I wanted to use them as backups for my 29er, so I built up some White Industries MI16s with Salsa Delgado Cross's. Still on the lighter side, but I can run 25's up to 2.3's and gain a lot of utility.