Disc road bikes - your opinion

[CAMPYBOB]

Bah! *****slapping is mo betta fun!

Retro Grouch has some very cool insights and comments on the hype...er...advertising ******** slung about regarding the 'need' for disco brakes:
http://bikeretrogrouch.blogspot.com/2013/11/hydraulic-and-disc-brakes-again.html


Gems:

From SRAM: "The way people are riding their bikes these days - the consistency - the power - making sure they can ride in all weather conditions, I think it's going to be a great advantage for people. Once you try it, you'll adopt it."

How exactly are people riding their bikes differently these days? And I have "tried it," and I'm not yet convinced.

From Storck: "It's definitely the future."

I can't wait.

From Focus: "There's always an overheating issue with carbon fiber rims and caliper brakes . . . it's one of the main reasons." (for going to disc brakes, that is)

<Me> Hasn't the 'problem' of high temperature carbon resin been already solved? All the manufacturers are advertising their rims as being able to glow in the dark without risk of structural failure. I've yet to see a rim failure at this year's Giro and some of those descent were 1/2 hour in length.

 

[jhuskey]

Originally Posted by CAMPYBOB
Bah! *****slapping is mo betta fun!

Retro Grouch has some very cool insights and comments on the hype...er...advertising ******** slung about regarding the 'need' for disco brakes:
http://bikeretrogrouch.blogspot.com/2013/11/hydraulic-and-disc-brakes-again.html


Gems:

From SRAM: "The way people are riding their bikes these days - the consistency - the power - making sure they can ride in all weather conditions, I think it's going to be a great advantage for people. Once you try it, you'll adopt it."

How exactly are people riding their bikes differently these days? And I have "tried it," and I'm not yet convinced.

From Storck: "It's definitely the future."

I can't wait.

From Focus: "There's always an overheating issue with carbon fiber rims and caliper brakes . . . it's one of the main reasons." (for going to disc brakes, that is)

<Me> Hasn't the 'problem' of high temperature carbon resin been already solved? All the manufacturers are advertising their rims as being able to glow in the dark without risk of structural failure. I've yet to see a rim failure at this year's Giro and some of those descent were 1/2 hour in length.

Sidesaddle?

 

[CAMPYBOB]

Tom Ritchey, noted builder, racer and rider on disco brakes:

On Road Disc Brakes:
The argument for disc brakes is incompatible with the argument for lighter bikes and wheels. But because the UCI-level race bikes are subject to minimum weight restrictions, the bikes often TOO light. This allows the use of a heavier brake system on a bike that’s still right at the weight limit,. The benefit is really all about wet weather braking. It’s an interesting thing for teams. But teams currently have to manage road bikes, spares, time trial bikes and now wet weather bikes. I don’t think top pro riders will want to use disc brakes in dry conditions. Existing road rim brakes are technically large disc brake systems, and are still going to be better than a small disc rotor system in most dry conditions. A 700c rim acting as a rotor manages heat better and has better braking sensitivity… nobody thinks about that. And due to the strength and heat management requirements, disc brakes will add weight to the wheels, where it’s most noticeable. I don’t think racers will want that unless wet conditions demand it. I think that much of the interest for disc brakes is coming from mountain biking, but way you stop on a mountain bike is completely different than how you stop on the road, and there are some trade-offs.

http://www.roadbikereview.com/reviews/2013-predictions-tom-ritchey-of-ritchey-design

 

[CAMPYBOB]

Quote by JH:
"Sidesaddle?"

Now...doesn't that depend completely on the length of your skirt?



Just asking...I'm not from Caleefornya and have never been to the Blue Oyster.

 

[CAMPYBOB]

Which professional racers want discos"

Well...Andy Schleck does, for one...

"Do the pros want discs? Some do and some don't, probably. Andy Schleck does."
http://road.cc/content/blog/96531-shimano-road-discs-final-thoughts-now



Ok..."Mr. I can't shift to save my ass not even widdy da Dura-Ass" Schleck wants discs.

Put a fork in it. It's done.

No discos for me if My Little Pony Bronies want discos.

 

[Colnago62]

Hey, I don't care what brake system you use as long as you don't crash into the back of me.

 

[swampy1970]

Has anyone apart from me ridden an MTB with a good set of hydraulic disk brakes on - or are y'all just putting up comments based on what you've read?

 

[AyeYo]

Originally Posted by CAMPYBOB
Tom Ritchey, noted builder, racer and rider on disco brakes:

On Road Disc Brakes:
The argument for disc brakes is incompatible with the argument for lighter bikes and wheels. But because the UCI-level race bikes are subject to minimum weight restrictions, the bikes often TOO light. This allows the use of a heavier brake system on a bike that’s still right at the weight limit,. The benefit is really all about wet weather braking. It’s an interesting thing for teams. But teams currently have to manage road bikes, spares, time trial bikes and now wet weather bikes. I don’t think top pro riders will want to use disc brakes in dry conditions. Existing road rim brakes are technically large disc brake systems, and are still going to be better than a small disc rotor system in most dry conditions. A 700c rim acting as a rotor manages heat better and has better braking sensitivity… nobody thinks about that. And due to the strength and heat management requirements, disc brakes will add weight to the wheels, where it’s most noticeable. I don’t think racers will want that unless wet conditions demand it. I think that much of the interest for disc brakes is coming from mountain biking, but way you stop on a mountain bike is completely different than how you stop on the road, and there are some trade-offs.

http://www.roadbikereview.com/reviews/2013-predictions-tom-ritchey-of-ritchey-design

Exactly what I've been saying since the first post.

Originally Posted by swampy1970

Has anyone apart from me ridden an MTB with a good set of hydraulic disk brakes on - or are y'all just putting up comments based on what you've read?

Yes and I shared my experience with their heat handling ability vs. rim brakes on the same hill.

 

[swampy1970]

Heat in disk brakes isn't an issue unless you mystically get off the bike and play "hug the disk" If you like making your fingers toasty I'd also suggest grabbing the disk on a bike trainer with magnetic resistance, a soldering iron or just putting your digits into a fire Overheating a rim when you have clincher tires or a craptastically glued on tubular tire = not good. Rollin, Rollin' Rollin, rawhide! Literally.

 

[AyeYo]

Overheating the disc is a huge deal because vaporized fluid means loss of brakes. That's why cars have thick, vented discs with cooling vanes, unlike bikes that have solid, thin light weight discs. Light weight disc brakes should be an oxymoron. Overheating an aluminum rim is exceedingly difficult not currently an issue.

 

[oldbobcat]

Originally Posted by AyeYo

Overheating the disc is a huge deal because vaporized fluid means loss of brakes. That's why cars have thick, vented discs with cooling vanes, unlike bikes that have solid, thin light weight discs. Light weight disc brakes should be an oxymoron.

Overheating an aluminum rim is exceedingly difficult not currently an issue.

Shimano rotors for road disc are of three-layer construction, stainless steel on the outside for durability and friction, and aluminum on the inside for heat dissipation. And the calipers and pads are vented. Shimano put a lot of work into this to get it right for performance riders who will use their brakes strategically and turkeys who will drag their brakes at 28 mph all the way down the mountain.

I don't yet know what SRAM and Campagnolo are up to, but I'm sure it's homework.

I'm not saying that everyone should go out and buy road disc brakes. I am saying that the technical objections have been addressed. Except the tiny contact patch of a 700c x 23 mm tire.

 

[swampy1970]

Overheating the disc is a huge deal because vaporized fluid means loss of brakes. That's why cars have thick, vented discs with cooling vanes, unlike bikes that have solid, thin light weight discs. Light weight disc brakes should be an oxymoron. Overheating an aluminum rim is exceedingly difficult not currently an issue.

I know what the theoretical heat issues are - vapor lock and brake fade. You don't need whacking great big brake rotors that are vented like cars have. This is a pair of really skinny disks on a factory Yamaha superbike - a bike that regularly sees 190mph on the track. Judging by the tires, someone has been having some fun.

A lot of these "issues" will already have been addressed by the decade or so of disk brake use by the lads on mountain bikes. The last really good ride I had on a mountain bike with hydraulic disk brakes was in 2006 and those were absolutely fecking phenomenal. I've not had chance to have a hard ride one of the latest road bikes with disks such as the Volagi's or Colnago.

 

[AyeYo]

When is the last time you rode a disc mountain bike on slicks down a large hill at high speed? There's a big difference between using brakes at 15mph on loose dirt and 50mph on pavement.

 

[swampy1970]

I wasn't on slicks then - but wasn't on full downhill knobblies either. Top speed was only about 35mph but that was down a nicely surfaced road at 1 in 5 (20%) with a hairpin at the bottom. Braking was very late and very controlled. The slightly knobbly tires squirmed a bit but it was all good fun.

If discs got so hot that they caused all manner of mayhem they'd start to melt, or at least cause to fail/deform, the aluminum mounts on MTB suspension forks. I've not heard of that happening. I've heard people say that rain will evaporate nearly instantly of a hot caliper and that rotors have discolored indicating that things have got mighty hot...

... then again, HED won't sell their Vanquish carbon rims despite the rims not failing under braking - the tires do. Apparently repeated heating to 400F and cooling causes tires to fail. I don't like tires failing. Heat seems to be an issue with most carbon rims, even tubulars (note Andy Schlecks comments), but due to the benefits of carbon hoops such as aero and comfort, I don't see them going away anytime soon.

Imagine MTB brakes on a World Cup downhill race getting so hot that the oil in the suspension forks spooged out under pressure. Ace stuff! Death by boiling oil - Esmeralda, the bells, the bells!!

If a World Superbike motorcycle can survive on the track with 320mm rotors then I'm not going to be overly concerned with running 160 mm or 180mm rotors on a push bike. WSB, unlike MotoGP, has to use steel or alloy brake rotors that are surprisingly similar in design to the floating units that Shimano make.

 

[CAMPYBOB]

Quote by OBC:
"I don't yet know what SRAM and Campagnolo are up to, but I'm sure it's homework."

SRAM? Well, they are up to a recall. Just like shimaNO. With the customer/consumer being the Beta Crash Test Dummies testers.

 

[swampy1970]

If disk brakes take off, it'll take Campagnolo about 10 years to get a system ready unless the pay AP Racing or Brembo a ton of money... ... It took them what, two decades to get EPS ready? Like with most things, once you get the Pros on board then serious development will happen - unless the lads from Giant Shimano get forced into using them during winter training

 

[CAMPYBOB]

Quote by Swamped:
"... It took them what, two decades to get EPS ready?"

One can not rush perfection. EPS just crushed the malfunctioning shimaNO **** at the Giro. Again.

That Campy disco pictured above was out almost a year ago and developed for the Colnago C59 disco. Scheduled commercial sales are for the 2015 model year.

Only two recalls behind shimaNO!

 

[alfeng]

Originally Posted by swampy1970
I wasn't on slicks then - but wasn't on full downhill knobblies either. Top speed was only about 35mph but that was down a nicely surfaced road at 1 in 5 (20%) with a hairpin at the bottom. Braking was very late and very controlled. The slightly knobbly tires squirmed a bit but it was all good fun.

If discs got so hot that they caused all manner of mayhem they'd start to melt, or at least cause to fail/deform, the aluminum mounts on MTB suspension forks. I've not heard of that happening. I've heard people say that rain will evaporate nearly instantly of a hot caliper and that rotors have discolored indicating that things have got mighty hot...

... then again, HED won't sell their Vanquish carbon rims despite the rims not failing under braking - the tires do. Apparently repeated heating to 400F and cooling causes tires to fail. I don't like tires failing. Heat seems to be an issue with most carbon rims, even tubulars (note Andy Schlecks comments), but due to the benefits of carbon hoops such as aero and comfort, I don't see them going away anytime soon.

Imagine MTB brakes on a World Cup downhill race getting so hot that the oil in the suspension forks spooged out under pressure. Ace stuff! Death by boiling oil - Esmeralda, the bells, the bells!!

If a World Superbike motorcycle can survive on the track with 320mm rotors then I'm not going to be overly concerned with running 160 mm or 180mm rotors on a push bike. WSB, unlike MotoGP, has to use steel or alloy brake rotors that are surprisingly similar in design to the floating units that Shimano make.

FWIW. For those who may be arithmetically challenged ...

Half the diameter of a given circle, one quarter the surface area ...

I only mention it because it would seem that the inference was otherwise such that the 160mm-or-180mm rotors could-or-would have half the capabilities of the 320mm rotors exclusive of caliper/lever considerations.

 

[swampy1970]

FWIW.  For those who may be arithmetically challenged ...              Half the diameter of a given circle, one quarter the surface area ...  I only mention it because it would seem that the inference was otherwise such that the 160mm-or-180mm rotors could-or-would have half the capabilities of the 320mm rotors exclusive of caliper/lever considerations.

Effective surface area with regards to braking is governed more by pad size. Not sure if anyone will every want an 8 pot caliper on a bicycle but it'd look cool. Reducing the size of the rotor does not give a proportional reduction in braking amongst different applications due to different materials used based upon heat and friction requirements. You could probably run a pad on a bicycle that would be chewed up in seconds on a motorcycle.

 

[swampy1970]

Quote by Swamped: "[COLOR=181818]... It took them what, two decades to get EPS ready?"[/COLOR] [COLOR=181818]One can not rush perfection. EPS just crushed the malfunctioning shimaNO **** at the Giro. Again.[/COLOR] [COLOR=181818]That Campy disco pictured above was out almost a year ago and developed for the Colnago C59 disco. Scheduled commercial sales are for the 2015 model year.[/COLOR] [COLOR=181818]Only two recalls behind shimaNO![/COLOR]

Looks like Campag braking is at the usual **** poor standard and they're still working on "perfection" then as the Colnago seems to come with Formula calipers and rotors...