UCI-approved road bike disc brakes coming in 2016, says WFSGI's bike man

Thanks @adamthekiwi for answering that nonsense. Armchair experts are creeping out of the woodwork. Having ridden discs on MTB for some 8 years or so, I'll quite happily state that anyone who claims changing a disc braked wheel is slower than a rim braked one is speaking drivel. In fact, discs are QUICKER since they do not have to be released and then reset like side-pull or v-brakes.

The only time the pads will close is if someone pulls on the brakes while the disc wheel has been removed: the sort of tyro mistake no competent race mechanic would make.

Either many of the response come from people who don't use discs a lot or they don't maintain their bikes well. I went to discs on the MTB very early on and regularly swap wheels around as its quicker than changing tyres. Can't remember ever having to spread the pads, just like I don't on the dozens of motorcycles I have had with discs.
As the stupid UCI have imposed lawyers lips anyway I can't see through axles being much of a handicap. It is a shite idea though as pulled axles can contaminate if dropped in the gravel and they are really just a solution that isn't really finished yet. Not needed at the back IMO.
Both my road bikes have discs. From experience (how much of the above is?) they are no more likely to lock up. Indeed possible less in poor conditions as when you are fighting a wet braking surface your are not having to pull as ahrd.
Re amateurs. so what. They can change when they want to.
Discs can be safer. I get a bit of arthritis and my hands ache on long descents. Discs mean I brake less and with less effort. Quite possibly that poor girl who died recently, Devon? not the one in Winnants might be alive as the verdict suggested cyclist's palsy.Maybe the other one might have not had problems either. Guess work of course.
Looks. Well road bikes went to shit when black came away from the tyres.
Of course many people don't need discs, good luck but some do.
Can't see it being a problem in races. Any injuries are going to be trivial. A hot disc will burn but so does gravel rash.

There's an awful lot of cr@p on this thread, most of which seems to be promulgated by people who have never ridden discs.

Badly set up disc brakes suck, but slightly less hard than badly set up rim brakes.

Contrary to popular belief, disc brakes *do not* provide significantly more braking power than rim brakes - it's just more reliable, more controllable and works as well in the wet as in the dry. If anything, hydraulic discs offer much more modulation, and hence control, than rim brakes, so lock-ups become *less* likely, not more.

Changing wheels is trivial with discs, once you're used to having to line up the rotor and caliper first - I've no idea where the myth that the pads automagically close up without any lever-squeezing unless there is a rotor between them has come from - mine have never done this.

BigBear63 wrote:

Disc brakes will make wheel changes slower. Pads have to be opened up before a new wheel can be inserted. All very time consuming. Which is why motor cycle racing generally doesn't bother, a bike swap is the only option.

What a load of rubbish. Pads do not need to be opened unless the brake lever has been compressed. Motorcycles don't change wheels because they don't have quick releases, they have large through-axles and no chain-tensioning derailleur cage to release the chain.

Correctly working bicycle disc brakes should neither drag or need to be opened up to fit a wheel. Not sure where you're getting that impression from.

There are good reasons why the pro-peloton won't use disc brakes but much of it will come down to perception rather than proven fact. For instance, Disc brakes are much heavier than rim brakes. Though weight could be shaved off elsewhere to compensate and still comply.

Disc brakes will make wheel changes slower. Pads have to be opened up before a new wheel can be inserted. All very time consuming. Which is why motor cycle racing generally doesn't bother, a bike swap is the only option.

Disc brakes generally have a small amount of drag but more than Rim brakes. A bit like having a hub dynamo. Not sure if this will be the case for road bikes but it's true for cars and motorbikes.

When it all comes down to it, as Jens Voigt said, 'who the hell uses brakes going downhill?'.

Okay, he was being a bit extreme as he understands that on hairpins, braking from 80KmH to 15KmH needs brakes but what advantage would discs be to someone who is a very fast descender anyway? The fast descenders are not usually great climbers so they won't want any extra weight on their bike and, generally, won't give a monkeys about slowing down.

It'll be interesting to see how it develops.

Sounds more like a closed system than an open.

Could be some interesting innovation around road discs and the changing of wheels.

Basically they will need to find a way to adjust 2-3mm either way from neutral on the fly. I am sure there will be a way to do that... just needs working out.

I think my only hang up with going over to discs is the wheel change and the adoption rates... as mentioned, two speed braking would not be a nice thing in a race, especially in the wet so it would have to be, one over, all over to discs.

disc brakes look awful on road bikes. they should be kept on mountain bikes

I can however see wheel ejection issues re-surfacing and would like to see more manufacturers adopt the 15mm through axle design from MTBs. Some already are.

I believe phenolic resins don't so much withstand the temperatures as absorb the heat in combustion. They are in fact designed to burn.

My R785s are great though, they pretty much remove all thoughts of anything between your finger and the tyre contact patch with the ground. I did think at first that the braking experience was a little bit exciting and I felt close to locking up, then I went riding with someone else on rim brakes and realised just how late I was braking in comparison. The other week I did lock up on a narrow steep gravelly Welsh lane but found that correction in such circumstanced is a lot easier and less exciting. The rider behind me on rim brakes also locked up. He took a little longer to appear at the bottom of the hill.

Back in the 90s there was a very similar discussion on the value of disc brakes on MTBs, that was when rims were considered a replaceable part. I think before long we will be filing this one away with that and the arguments about carbon fibre being an inappropriate material for the manufacture of bicycles.

I think that this is great news. Just enough time to hopefully have a choice from Shimano, SRAM and Campy but not so long that I can't wait to get a new bike with discs

Not to mention how a compulsory disc brakes will affect grassroots racers, who suddenly have the choice of buying new high end bikes or stop racing.

Because there are legitimate safety concerns as well as a need to keep the playing field relatively even which has to be carefully balanced with the commercial requirement of the sponsors to sell new stuff.

I don't understand why they don't just make them legal now and allow the manufacturers and teams to sort things out themselves. You can guarantee that if there is a performance improvement to be had, many of the issues will be ironed out amazingly quickly.

My Kinesis Racelight T2 will be the last rim braked bike I ever have. One with discs would be perfect.

I'm holding out until we have electronically actuated disc brakes, with an ABS fitted. Even then, I might hold out a bit longer for the chain free bike - a variable resistance dynamo in the crank powering a motorised hub, and do away with such archaic tech like chains. Everyone wins, no more lubes, no more chain wear, infinite gears...

It'll change racing.

I'll change to disc brakes when my Ti frame packs up, i.e. never.
I'm sure they are better but I just don't give a crap, braking is overrated anyway.

"Re changing wheels, taking the wheel off and putting it back on seems no worse than rim. Nothing technically difficult for the likes of Shimano, it's not like disc brakes have just been invented. Normally hydraulic brakes the pads self centre after one operation and the pads pull back when the lever is released, giving clearance."

This may be your experience with a single bike/wheel combo when changing wheels but because the pad clearances are so small this will be difficult even within a team, never mind neutral service. Hubs, frames, calliper position will all need to be maintained to tight tolerances. Rotors do warp/bend slightly. Cable discs will be a no-no for quick wheel changes as the pads need to be adjusted. I used to swap wheels with different hubs on a mountain bike with hydraulic discs and needed to fettle the calliper each time.

This is going to make for nightmare wheel changes in races, not to mention poor bike handlers in pelotons slamming full-on, locking and taking others down too. Not to mention improved brake grip in the wet, when the road surface grip is disappearing.

If it ain't broke...