Disc brakes to be permitted in peloton in 2017

hampstead_bandit wrote:

Only noise I get from my disc brakes is a tiny tinkle from the Shimano Ice-Tech cooling fins on the brake pads, but no rotor rub - if the rotors were rubbing something has gone very wrong with either the brake or the wheel axle!

Want!

mrmo wrote:

For those commenting on weight saving, light mtb rims weighed c400grams before discs and still weigh c400grams. Think of it like this, Mavic GEL280's how many rims can you buy now that are lighter? do you really think you can make a aluminium structure any lighter if you remove the braking surfaces. (Carbon is a different question)

Modern rims are usually wider, that material has shifted from a thicker sidewall.

The other thing is that the modern rim profiles are also optimised for strength, using the same material from the sidewall.

And I can't recall rims as light as Stan's are when I still used v-brakes, except as very high end racing rims. With a life expectancy of... not much.

Stan's Alpine are 330 grams in 25", and the Crest are 340 grams. The light 29er rims today weigh the same 400-450 grams or so that 26" rims did 12-15 years ago... and those were the light ones. Larger hoops weigh more.

Simmo72 wrote:

Danger of injury from discs in a crash, again specifically within the peleton.

What a bunch of hen-clucking. Might as well get rid of chainrings, after all, they do have teeth.

crazy-legs wrote:

Quote:

Yeah, because a pair of track rims save a good kilo compared to road rims don't they.

Your sarcasm is wasted - track wheels are built for stiffness and aerodynamics, weight is very much a lesser issue in the controlled environment of a velodrome.

Removing the brake track from road (or CX,/MTB etc) wheels is a massive boost to performance, you can build the wheel stiffer, more aerodynamic, stronger, lighter, wider...
All without the constraints and fragility of a parallel machined rim.

It's not solely about weight.

You have just contradicted your own argument there. You say track wheels are built to be stiff and aerodynamic and are heavy despite having no brake track. Next you propose that removing the brake track is going to result in stiffer more aerodynamic wheels that are also lighter.

Furthermore if removing a parallel rim could do all this why has is not been done with track wheels already. That controlled environment would be a perfect place to perfect the rim profile.

jacknorell wrote:

Modern rims are usually wider, that material has shifted from a thicker sidewall.

The other thing is that the modern rim profiles are also optimised for strength, using the same material from the sidewall.

And I can't recall rims as light as Stan's are when I still used v-brakes, except as very high end racing rims. With a life expectancy of... not much.

Stan's Alpine are 330 grams in 25", and the Crest are 340 grams. The light 29er rims today weigh the same 400-450 grams or so that 26" rims did 12-15 years ago... and those were the light ones. Larger hoops weigh more.

Mavic m230 were 380grams and used eyelets? and that was 20 years ago. You mention that rims are wider, so the metal has been relocated.

http://weightweenies.starbike.com/listings/components.php?type=rims

if you look rim weights have actually been fairly static with the odd stupidly light one.

mrmo wrote:

jacknorell wrote:

Modern rims are usually wider, that material has shifted from a thicker sidewall.

The other thing is that the modern rim profiles are also optimised for strength, using the same material from the sidewall.

And I can't recall rims as light as Stan's are when I still used v-brakes, except as very high end racing rims. With a life expectancy of... not much.

Stan's Alpine are 330 grams in 25", and the Crest are 340 grams. The light 29er rims today weigh the same 400-450 grams or so that 26" rims did 12-15 years ago... and those were the light ones. Larger hoops weigh more.

Mavic m230 were 380grams and used eyelets? and that was 20 years ago. You mention that rims are wider, so the metal has been relocated.

http://weightweenies.starbike.com/listings/components.php?type=rims

if you look rim weights have actually been fairly static with the odd stupidly light one.

Sure, some were stupid light back then.

Average rims are about the same weight now. But we don't hear the phrase 'wheel taco' very often anymore... as they're much stronger at the same weight or even lighter.

The Stan's rims are pretty solid, and the 400 gram ones are all-trail ones.

Anyway, the point (not necessarily directed at you) is that rims have got better as in wider and stronger at same weight. And lighter ones are now reliable.

We'll see the same with road rims as discs become commonplace.

Someone made the argument that removing the brake track wouldn't lighten or strengthen rims, and that's just poppycock. The flat pressure-tolerant horizontal surface isn't very helpful for the lateral structural strength needed for a rim.

jacknorell wrote:

Someone made the argument that removing the brake track wouldn't lighten or strengthen rims, and that's just poppycock. The flat pressure-tolerant horizontal surface isn't very helpful for the lateral structural strength needed for a rim.

Yeah, because a pair of track rims save a good kilo compared to road rims don't they.

.

millskid wrote:

My advice would be to stay away from a bike with disc breaks.

Totally agree - if the discs are broken, they need to be replaced immediately.

millskid wrote:

I have a mountain bike with hydraulic discs and it causes me no end of problems.

Really? I have 2 mountain bikes and a touring bike with hydraulic discs and I have no problems at all. Mine haven't even needed bleeding, other than at installation - they get fluid replacements about once every 2 years, or thereabouts, and new pads when needed (varies depending on how often and in what conditions they're running). My road bike has cable-operated calipers - they need tweaking more regularly, but no more than cable-operated rim-brakes did. There is some rub on these, but they're single-piston, so that's not so surprising.

Hey ho - YMMV. Don't really understand why disc brakes, more than any other type of component, seem to divide folk into massively happy and absolutely dead-set-against (often without any actual experience of them).

For me, if they're badly set-up and maintained, they as much of a PitA as badly-setup/maintained rim brakes. Well set-up and installed hydraulic disc brakes are a maintainer's dream - they need almost no input - and are reliable, consistent and controllable in all conditions. They're (obviously) tolerant of less-than-perfectly-true rims, and rim life is no longer limited by how thick the braking surfaces are. Overheating is a possible issue for road bikes on long descents - rear-brake-dragging is common for stabilisation, and that's a lot of heat to dissipate from a 140mm rotor. I've never had the "slight lateral movement in the wheel" issue, but then I maintain my bikes.

I'm not certain how much advantage there will be for racers, who have maintenance teams, unlimited rims and new brake pads whenever they need them. More consistent and controllable braking is the only real advantage as far as they're concerned...

millskid wrote:

My advice would be to stay away from a bike with disc breaks. If there is a slight lateral movement in the wheel, the brakes will rub against the wheel. This causes a lot of rolling resistance, the slightest twist in the wheel rim or expansion of the metal will cause problems.

I have a mountain bike with hydraulic discs and it causes me no end of problems.

That is boll@cks, the disc is mounted on the hub. The wheel can buckle to hell and it won't affect the braking. It would need the bearing s or spindle to bend and that could happen to a rim wheel just as easily. But since it a rare occurrence and probably only happens on poorly maintained bikes.

Unless your wheel runs perfectly true through the brake it will rub against the pad (i.e when putting the wheel back on after a flat, if the wheel is not aligned perfectly you will have problems). There is no room for error.

I have Avid Juicy Hydraulic Disc Breaks, trust me they rub. You can ride through the friction obviously, however, that is not the point. My bike is not poorly maintained by the way. A good test is to free spin your back wheel by hand and you will notice even the slightest rubbing. Its good to compare it against a bike without disc brakes.

Go and buy a very expensive road bike with disc breaks and when they start to rub after a bump, or loose nut don't moan about it.

Disc brakes are amazing when working well, I just don't think they are worth the hassle.

millskid wrote:

Unless your wheel runs perfectly true through the brake it will rub against the pad (i.e when putting the wheel back on after a flat, if the wheel is not aligned perfectly you will have problems). There is no room for error.

Eh ? Your disc is attached to your hub. Your calliper is attached to your fork. Which one of those knows you've had a flat ? You'd have to have a fairly fucked alignment to cause an issue.

millskid wrote:

Unless your wheel runs perfectly true through the brake it will rub against the pad

A good test is to free spin your back wheel by hand and you will notice even the slightest rubbing. Its good to compare it against a bike without disc brakes.

I have shimano xt disc brakes, they never rub, no servicing for years. I've had more issues with caliper brakes where the calipers close from both sides, but open up more to one side.

Any misalignment will be more pronounced at the rim than at the brake disc, so if it would rub with disc brakes it will rub on the rim with rim brakes. Really if you push the wheel fully into the grooves it will be aligned sufficiently not to rub on discs.

wycombewheeler wrote:

Any misalignment will be more pronounced at the rim than at the brake disc

True enough. But...

wycombewheeler wrote:

so if it would rub with disc brakes it will rub on the rim with rim brakes.

...isn't the clearance for rim brakes greater than that for disc brakes? I don't have disc brakes so I don't know for myself.

millskid wrote:

Unless your wheel runs perfectly true through the brake it will rub against the pad (i.e when putting the wheel back on after a flat, if the wheel is not aligned perfectly you will have problems). There is no room for error.

I have Avid Juicy Hydraulic Disc Breaks, trust me they rub. You can ride through the friction obviously, however, that is not the point. My bike is not poorly maintained by the way. A good test is to free spin your back wheel by hand and you will notice even the slightest rubbing. Its good to compare it against a bike without disc brakes.

Go and buy a very expensive road bike with disc breaks and when they start to rub after a bump, or loose nut don't moan about it.

Disc brakes are amazing when working well, I just don't think they are worth the hassle.

Thats tosh!
As stated before, If they're set up well you shouldnt get this.
Ive used HOPE on my MTB since the late 90's and discs on my road bike and have never had this on either. If you are then maybe try a better brand, there's lots out there!

As for losing bolts and rubbing by going over bumps??? In all my years of XC MTB racing Ive never had this and there's been some very bumpy courses along the way. Stating this with regards discs on road bikes is total bobbins. ....jeez, what kind of roads are you riding???!!

thegibdog wrote:

Discs have been allowed in cyclocross for a couple of years now but in the big races you'll only see 1 or 2 of the top riders on discs. It will be interesting to see the level of take up on the road.

The UK-based Hope 'cross team were running discs in 2011 and the riders I spoke to wouldn't want go back to canti brakes.

At the top level Giant's CX riders are all on disc and among the others Helen Wyman is a disc convert (2013 interview). One reason that discs are not universal is because many of the eperienced CX riders are so accustomed to cantis that they are reluctant to change.

glynr36 wrote:

Surely you must understand peoples skepticism on having to get a new frame/wheels/50% of a gruppo to see these benefits some of the industry keeps going on about.

I think Dave was just demonstrating the comparative reactions. Many new models are being sold with discs now and they're hardly any more expensive than the rim-braked version.

Looking at the sheer number of upgrade threads on here there are lots of people with plenty of money to burn on components to save 300g or trying to keep up with the Joneses.

Paul J wrote:

Discs weigh more, have a larger winded area (especially in cross-winds) and tend to rub more.

Same applies to deep section wheels.

Paul J wrote:

What I would hate to see is an aero or weight arms race. Minimise the influence of tech R&D expenditure on racing, please!

You're following the wrong sport. Tech is at the heart of it because the manufacturers sponsor teams. Why? Because it sells. I am not enamoured with the tech 'arms race' but as long as we can still get 7/8/9 speed parts and rim-braked wheels cheaply I'm happy for others to have whatever they can afford.

Re. the 6.8kg limit - I'm not the least bit fussed about the weight limit. It won't change the racing, it's purely about marketing.

Paul J wrote:

watch out when you're buying road 135mm-rear discs. That might not last long as a "standard".

Pure scaremongering bullshit. While 135mm hubs can be bought, like those on many MTBs and 'cross bikes, then 135mm wheels can be built.

thegibdog wrote:

Discs have been allowed in cyclocross for a couple of years now but in the big races you'll only see 1 or 2 of the top riders on discs. It will be interesting to see the level of take up on the road.

In UK and Europe perhaps - try looking at the US races.

fukawitribe wrote:

thegibdog wrote:

Discs have been allowed in cyclocross for a couple of years now but in the big races you'll only see 1 or 2 of the top riders on discs. It will be interesting to see the level of take up on the road.

In UK and Europe perhaps - try looking at the US races.

of the top 16 riders at the CX worlds, six used discs, including the men's and women's elite winners

http://www.cxmagazine.com/podium-ride-tech-analysis-2015-tabor-world-cyc...

Dave Atkinson wrote:

fukawitribe wrote:

thegibdog wrote:

Discs have been allowed in cyclocross for a couple of years now but in the big races you'll only see 1 or 2 of the top riders on discs. It will be interesting to see the level of take up on the road.

In UK and Europe perhaps - try looking at the US races.

of the top 16 riders at the CX worlds, six used discs, including the men's and women's elite winners

http://www.cxmagazine.com/podium-ride-tech-analysis-2015-tabor-world-cyc...

So 10 didn't?

mrmo wrote:

Dave Atkinson wrote:

fukawitribe wrote:

thegibdog wrote:

Discs have been allowed in cyclocross for a couple of years now but in the big races you'll only see 1 or 2 of the top riders on discs. It will be interesting to see the level of take up on the road.

In UK and Europe perhaps - try looking at the US races.

of the top 16 riders at the CX worlds, six used discs, including the men's and women's elite winners

http://www.cxmagazine.com/podium-ride-tech-analysis-2015-tabor-world-cyc...

So 10 didn't?

So 3-6 times as many as posited by thegibdog. From

http://www.bicycling.com/cyclocross/powers-and-compton-keep-national-cyc...

Compton opted to ride her Trek Boone, equipped with disc brakes rather than her preferred cantilevers. She spoke with us about her gear decision for the muddy course: "I pre-rode on my cantis and they were just clogging up, and I had my discs here so I decided to ride them. They were perfect."

Like Compton, Powers elected to run disc brakes—as did all of the top racers. While he prefers canti brakes in most conditions, he said, "The disc brakes were super good for me, especially on those steep, fast descents. I never felt like I was out of control.”

Interesting from Powers, pragmatic too.

mrmo wrote:

Dave Atkinson wrote:

fukawitribe wrote:

thegibdog wrote:

Discs have been allowed in cyclocross for a couple of years now but in the big races you'll only see 1 or 2 of the top riders on discs. It will be interesting to see the level of take up on the road.

In UK and Europe perhaps - try looking at the US races.

of the top 16 riders at the CX worlds, six used discs, including the men's and women's elite winners

http://www.cxmagazine.com/podium-ride-tech-analysis-2015-tabor-world-cyc...

So 10 didn't?

yup, 10 didn't. that's for the top four riders in each category, i don't know what the overall splits were, probably a lesser percentage of discs overall

roadie.ronan wrote:

I hope in road the industry keeps it simple not like what is happening in the mtb side of things with about 5 different thru axle standards for a rear wheel its a joke.

Why would they keep it simple? The business people at the manufacturers are *salivating* over the chance to "segment" the market by having lots of different standards. The manufacturers DONT WANT ONE STANDARD. The more standards there are, the more opportunities there are to sell you more products.

E.g., if there was one standard, you might buy one set of race wheels and one set of training wheels for your road bikes. Or you might carry your old set of wheels over when you buy a new bike. With multiple standards, the more standards there are, the more likely it is that you will need to buy *multiple* wheels for your different bikes. This means more money for the vendors.

The more "standards" there are, the more sales opportunities for the vendors. They *love* this.

The only downside is creating the standard takes upfront investment, as can getting other vendors to adopt and ship significant amounts to make the costs worth it. That's been the only check on things.

Look at bottom brackets and the explosion of press-fit bearing standards. (Hilariously, there is now that new bottom-bracket which fits into press-fit cups, but screws the 2 sides together through the bottom bracket, to address the squeaking issues).

Paul J wrote:

Why would they keep it simple? The business people at the manufacturers are *salivating* over the chance to "segment" the market by having lots of different standards. The manufacturers DONT WANT ONE STANDARD. The more standards there are, the more opportunities there are to sell you more products.

yes I agree, I think though possibly with road racing and how common/important the replacement of wheels is. I'm hoping they just stick with a quick release. Again Giant are using this and have stated there is no need for anything else.
I don't buy specialized purely because of all their weird little standards. Their bikes are already expensive. I am mainly a mountain biker and they always have some non standard fitting like shocks to the bike or whatever and then when you want to get a part you cant get in touch with them. For this reason I think my next road bike will be Giant.

gazman428 wrote:

One the rims don't have pads pressing on them, rim design will move on and get lighter and the wheels will get better as weight at the rim is the worst place on a wheel imo.
I'm installing tubeless this afternoon on as soon as shimano release the std and it is accepted I will be getting a bike with it!

They won't, though. That bead holding your tyre onto the rim is the limiting factor, not the brake track.

My main concern, one that I'll need to see proven beyond doubt before I buy, is how they'll tackle brake fade on the lighter and lighter rotors the road industry will demand. Heavy rotors aren't really an issue on the other examples mentioned - but if a long descent can generate enough heat on a rim to burst tyres as was the case in Oman recently, I don't feel too optimistic about discs right now.