Value of rim brakes...

[oliver1850]

Originally Posted by Cicli

Heck, we have hills here. Not mountains but hills.
There is a 15-20 member group here in town that rides 25-35 miles four days a week. 100 on the weekend if you want. Year round. These people just get out and ride and have fun. Some gravel, some pavement. Nobody has discs. Some have bikes with as good as 105 on them. One guy really gets with it and he is on an alloy Nashbar bike with Sora.
Really puts it in prospective. Sometimes you can still ride a bike with a 9 speed cassette, rim brakes and cheap alloy frame. He has a blast and the bike dosent seem to be holding him back from having fun.
My rim brakes work fine.
BB30 was a fad at one time as well.

Lots to like in this post, especially the Sora.

Hillier where you are than where I am but it's still easy to go faster than I want to on lots of downhills here, considering animal traffic. Friend once surprised a guy on a Harley by passing him. He's always trying to hit 50 mph. Too many close calls with deer and squirrels for me, broken bones and really ugly contusions from racoon contact (twice).

I've yet to have discs on a road bike. Think they would be great for loaded touring.

[fogrider]

Originally Posted by oliver1850

Lots to like in this post, especially the Sora.

Hillier where you are than where I am but it's still easy to go faster than I want to on lots of downhills here, considering animal traffic. Friend once surprised a guy on a Harley by passing him. He's always trying to hit 50 mph. Too many close calls with deer and squirrels for me, broken bones and really ugly contusions from racoon contact (twice).

I've yet to have discs on a road bike. Think they would be great for loaded touring.

animal traffic on the roads? how slow are these animals? if they're a hazard to cyclist, there must be road kill from cars all over the place! my top speed yesterday was 43 mph and I didn't run over any animals or die with rim brakes...

I'm fine with rim brakes and they have come a long ways from when I started riding...

[dddd]

One thing seldom mentioned is the different load path of braking forces between rim brake and disc brake setups.
Having the full wheel braking torque change from being resolved symmetrically along both fork legs at a distance of 31cm to being resolved asymmetrically by one leg at a distance of just 8cm involves a huge change in the required strength and stiffness of the left half of the fork.

Then there is the same torque being resolved down to a distance of just 2.2cm or less(!) where the disc joins the hub, meaning that the peak force is now 28 times higher versus any part of a rim brake bike's braking system.

That enormous increase in peak loading must also resolve itself through the axle, hub and spoking to the rim, requiring a lot of redesign and reinforcement along the way.
There are frequencies that can excite that elastic load path into chatter just as a normal road bike's elastic fork can elicit the same sort of chatter, but the traditional road bike gets the benefit of some increase in ride quality from that flex originating in both fork legs instead of in the more complicated and concentrated load path of the disc braked bike.

So that detriment to ride quality and added weight of reinforcement must then be made up for with wider tires and rims made of lighter materials that allow lower air pressure (which admittedly offers the benefit of improved traction on loose and/or rough surfaces).
The wider tires then need more clearance, and the whole "mess" now needs much added attention to the frontal area aerodynamics.

The weight and cost of braking tracks added to an aero-shaped rim is minimal based on my shopping for carbon rims that are offered in both configurations, and the newest performance levels of Mavic's carbon rim braking should continue trickling down to the lower price points.

It is said that road bike sales are down, and I get the feeling that the media-driven push for disc braked road bikes is biased in order to stimulate road bike sales. I meet a lot of riders who are shopping for a new bike only because they want to get on board with the latest fashion, not because they have any actual need for disc brakes around here where it seldom rains. So they would not be buying a new bike at all except for the way that "fashion marketing" has influenced their thinking. Some of these riders who have made their purchase have told me how heavy that their new bike is, and I can only recall that "I told you so" but actually keep my mouth shut. I've noticed that some of these riders who didn't let go of their old bike are still often riding their old bike, and say that they like it better.
There are many exceptions to all that. But unless one is riding in the wet a lot, or riding off road with huge tires, discs may come at too dear of an overall price and that is the story not told by the cycling press.

[Burnette]

Originally Posted by dddd

One thing seldom mentioned is the different load path of braking forces between rim brake and disc brake setups.
Having the full wheel braking torque change from being resolved symmetrically along both fork legs at a distance of 31cm to being resolved asymmetrically by one leg at a distance of just 8cm involves a huge change in the required strength and stiffness of the left half of the fork.

Then there is the same torque being resolved down to a distance of just 2.2cm or less(!) where the disc joins the hub, meaning that the peak force is now 28 times higher versus any part of a rim brake bike's braking system.

That enormous increase in peak loading must also resolve itself through the axle, hub and spokes to the rim, requiring a lot of redesign and reinforcement along the way.
There are frequencies that can excite that elastic load path into chatter just as a normal road bike's elastic fork can elicit the same sort of chatter, but the traditional road bike gets the benefit of some increase in ride quality from that flex originating in both fork legs instead of in the more complicated and concentrated load path of the disc braked bike.

So that detriment to ride quality and added weight of reinforcement must then be made up for with wider tires and rims made of lighter materials that allow lower air pressure (which admittedly offers the benefit of improved traction on loose and/or rough surfaces).
The wider tires then need more clearance, and the whole "mess" now needs much added attention to the frontal area aerodynamics.

The weight and cost of braking tracks added to an aero-shaped rim is minimal based on my shopping for carbon rims that are offered in both configurations, and the newest performance levels of Mavic's carbon rim braking should continue trickling down to the lower price points.

It is said that road bike sales are down, and I get the feeling that the media-driven push for disc braked road bikes is biased in order to stimulate road bike sales. I meet a lot of riders who are shopping for a new bike only because they want to get on board with the latest fashion, not because they have any actual need for disc brakes around here where it seldom rains. So they would not be buying a new bike at all except for the way that "fashion marketing" has influenced their thinking. Some of these riders who have made their purchase have told me how heavy that their new bike is, and I can only recall that "I told you so" but actually keep my mouth shut. I've noticed that some of these riders who didn't let go of their old bike are still often riding their old bike, and say that they like it better.
There are many exceptions to all that. But unless one is riding in the wet a lot, or riding off road with huge tires, discs may come at too dear of an overall price and that is the story not told by the cycling press.

Ride quality isn't just wheels in isolation, the frame, sear post/saddle, bars and you all play a role along with those wheels and tires and so disc brake bikes can ride just fine thank you very much good sir.

In the aero department disc provide a tad more surface and room to develop different shapes because they aren't hampered by rim brake caliper limits and the design can go to the tire bead, so there's that.

"want to get on board with the latest fashion, not because they have any actual need " describes 99% in every "latest purchase thread ever and who here is without such guilt? Ha!

"Some of these riders" does not equate everybody who bought a disc brake bike, very small sample size and local anecdotal evidence is just that. The OP says more and more guys are showing up with disc at the group ride so there ya go, means nothing either definitive way.

And as far as weight goes you can get a disc bike down to legal limits and below if that's your thing.

Hey, ride what ya like and enjoy, both types of braking systems are valid IMO, it comes down to personal preference like all of our gear.

To the Op's question, it has always been a buyer's market in the used bike game and yes, I too believe it has been hotter than usual. To accredit it to disc brake bike popularity, I cannot say. But I have seen so many nice rim brake bikes even in my small size of late that it does make you wonder.

[Kontact]

Originally Posted by Burnette

Ride quality isn't just wheels in isolation, the frame, sear post/saddle, bars and you all play a role along with those wheels and tires and so disc brake bikes can ride just fine thank you very much good sir.

I don't know what you're getting at, here. Forks have definitely gotten much stiffer so they don't fail from hub braking. A fork can't be stiffer and still have the fine ride qualities it used to have.

[Burnette]

Originally Posted by Kontact

I don't know what you're getting at, here. Forks have definitely gotten much stiffer so they don't fail from hub braking. A fork can't be stiffer and still have the fine ride qualities it used to have.

Disc brakes and a good ride can go hand in hand.

[Kontact]

Originally Posted by Burnette

Disc brakes and a good ride can go hand in hand.

How does a fork that flexes less ride as well as one tuned to act as suspension?

[Burnette]

Originally Posted by Kontact

How does a fork that flexes less ride as well as one tuned to act as suspension?

If you can ride and do like a modern carbon road bike you can ride one with disc brakes.

[Kontact]

Originally Posted by Burnette

If you can ride and do like a modern carbon road bike you can ride one with disc brakes.

That isn't an answer to my question. That is Koolaid talk.

[Burnette]

Originally Posted by Kontact

That isn't an answer to my question. That is Koolaid talk.

Fine, if that's what you wish to believe.

[dddd]

I'll have to say that it is at least half of an answer, and actually a good point given that high-performance (strength/weight) structures generally leave less in the way of design freedom for that ride-tuned ability to absorb big hits.
My carbon bikes (Scott CR1, Orbea Orca and Colnago CX-zero) never had quite the ability to absorb road defects like a steel bike, but the Scott came closest so I would say that there are significant differences between brands.
Most of the pre-disc carbon bikes from 2000 on were more noticeably stiff in front than classic bikes, but I never had issues with a jarring ride at the saddle. When discs enter the picture it's pretty much a given that there won't be much compliance at the front end, unless a Lauf fork or suspension stem is added on. I generally like stiff bikes but the occasional hit at the front wheel sometimes leaves me with a bruised palm or two. I use relatively compliant saddles and ride light in the saddle so again no problems in back.
I get that these are first-world issues, and today's bikes are great regardless, but I do think that there is a cross-over point where a disc-braked road bike might or might not be the best choice in terms of performance per dollar.
That point is different for different riders doing different things in different areas.
I don't think that the UCI weight limit offers much of a validation for the added weight of disc-brake architechture, both because many riders aren't doing UCI races and because comparisons should be made at similar price points. One could speculate or might know why the UCI imposed such limits despite wide disparity in rider weights, but I think that cost considerations may have had a lot to do with it.
Again, pretty much all of today's road bikes are great imo, and buyer choice is a great thing and I'm glad that people enjoy their bike purchases whatever they choose.
I subscribe to Road Bike Action at the moment and became surprised at some point how much favor that they wrote about disc brake performance, but ignoring any more critical reviews of it. So it seems like the industry with advertising dollars counts a whole lot more than the subscription cost paid by the readers. They have since been more inclusive in their reviews of rim-brake models so I am at least hopeful that well-balanced comparisons might be made at some point as the trends mature. Specifically I would like to see similarly priced disc and rim brake models compared in comprehensive tests using same-sized bikes that can be exchanged back and forth between riders over familiar test loops and on longer rides over a range of road surfaces.

[Burnette]

Originally Posted by dddd

I'll have to say that it is at least half of an answer, and actually a good point given that high-performance structures generally leave less in the way of design freedom for that ride-tuned ability to absorb big hits.
My carbon bikes (Scott CR1, Orbea Orca and Colnago CX-zero) never had quite the ability to absorb road defects like a steel bike, but the Scott came closest so I would say that there are significant differences between brands.
Most of the pre-disc carbon bikes from 2000 on were more noticeably stiff in front than classic bikes, but I never had issues with a jarring ride at the saddle. When discs enter the picture it's pretty much a given that there won't be much compliance at the front end, unless a Lauf fork or suspension stem is added on. I generally like stiff bikes but the occasional hit at the front wheel sometimes leaves me with a bruised palm or two. I use relatively compliant saddles and ride light in the saddle so again no problems in back.
I get that these are first-world issues, and today's bikes are great regardless, but I do think that there is a cross-over point where a disc-braked road bike might or might not be the best choice in terms of performance per dollar.
That point is different for different riders doing different things in different areas.
I don't think that the UCI weight limit offers much of a validation for the added weight of disc-brake architechture, both because many riders aren't doing UCI races and because comparisons should be made at similar price points. One could speculate or might know why the UCI imposed such limits despite wide disparity in rider weights, but I think that cost considerations may have had a lot to do with it.
Again, pretty much all of today's road bikes are great imo, and buyer choice is a great thing and I'm glad that people enjoy their bike purchases whatever they choose.
I subscribe to Road Bike Action at the moment and became surprised at some point how much favor that they wrote about disc brake performance, but ignoring any more critical reviews of it. So it seems like the industry with advertising dollars counts a whole lot more than the subscription cost paid by the readers. They have since been more inclusive in their reviews of rim-brake models so I am at least hopeful that well-balanced comparisons might be made at some point as the trends mature. Specifically I would like to see similarly priced disc and rim brake models compared in comprehensive tests using same-sized bikes that can be exchanged back and forth between riders over familiar test loops and on longer rides over a range of road surfaces.

You can go a few threads down from here and to a great many other posts in the general forum and read fellow members here wax poetically about the great ride carbon bikes have, even those with disc brakes, it's not an issue for most. Again, if you can ride a modern carbon bike you an ride one with disc brakes.

For the bruised palms I can't help but feel a fit issue is there as too much is on your hands but I'm humble enough to say that you surely should know your body and fit better than I. Sounds painful though, I sincerely hope you find a solution that works for that.

The weight limit assertion I made was to only point out that some disc brake bikes are sold new already light weight off the rack if that's a want and the disc ready frames certainly can be built up as light as a wallet can handle.

I too agree with you that it's great that as cycling consumers we are saturated with great choices and if a person really likes their rim brake bike I of course think that's great. I'm in no way anti rim brake, that's absurd.

I use to catch a copy of Road Bike Action and I must say that I was always under the impression that most such magazines (car mags too) were as much advertisement pieces than anything so we agree there. I enjoyed them more for the news on new stuff. The internet of course does a quicker/better job so I don't get the mags like I use to. I will tell you this though, it's not marketing hype that some prefer disc and that they work great. So do rim brakes. Again, it's a personal preference thing.

This is where I land, at the end if the day both brake types work and are indeed valid and I can see where a cyclist could choose either according to his or her needs and wants and be fine with the decision.

[ColonelJLloyd]

Originally Posted by Kontact

How does a fork that flexes less ride as well as one tuned to act as suspension?

Horses for courses.

I find it hard to believe fork blade flex has much perceptible suspension value when I am rolling on 415g, 51mm (actual), tubeless slicks at 30psi. Not sure how much experience you have on a road bike with light, high volume tires like that, but it's substantially different than 23mm tires at 110psi.

[Kontact]

Originally Posted by ColonelJLloyd

Horses for courses.

I find it hard to believe fork blade flex has much perceptible suspension value when I am rolling on 415g, 51mm (actual), tubeless slicks at 30psi. Not sure how much experience you have on a road bike with light, high volume tires like that, but it's substantially different than 23mm tires at 110psi.

Yeah, I don't think about the ride qualities of MTB forks either. But 30 psi tires have more drag and are heavy, so I choose 25c tires for actual road bikes.

[ColonelJLloyd]

Originally Posted by Kontact

Yeah, I don't think about the ride qualities of MTB forks either. But 30 psi tires have more drag and are heavy, so I choose 25c tires for actual road bikes.

Cool, man. Sounds like you've got it all figured out.