Because it happened in crash.

How did his LEFT knee get mangled by a disc rotor?

Explain to us how that couldn’t happen then.

He said he just touched the other bike and kept riding, I can’t see how you can get your knee on the disc that way and at that angle. The cut suggests his knee was coming from a direction perpendicular to the wheel.

I didn’t actually fall down: it was only my leg touching the back of his bike. I keep riding.

With any good set of rim brakes on a road bike, braking power is limited by tyre traction, not the brakes.

Actually, on a dry road, it’s limited by the position of your centre of gravity relative to the front wheel contact patch.

Only in a straight line, with clean tarmac and good tyres.

Maybe his shin was abraded by the tyre?

Only in a straight line, with clean tarmac and good tyres.

dunno gm, you ride a hell of a lot more than me, but my braking’s been limited by pivoting over the front wheel on corners (not sharp corner, but well off the vertical), dirt, bracken, road, Schwalbe marathons, Conti mountain kings, V brakes and discs. This week.

Front wheel loosing grip has been off the brakes on roots, UK slop and grime, and loose corners.

I have contacted all the Pro teams who are running disc brakes to offer my services, i will, at my own expense collect all the bikes that now have this illegal technology and…erm…dispose of them.
i will also open this offer up to anyone who privately owns one of these death traps, just email me the Make, Model and spec, and i will arrange collection, free of charge of course.

otsdr – Member
He said he just touched the other bike and kept riding, I can’t see how you can get your knee on the disc that way and at that angle. The cut suggests his knee was coming from a direction perpendicular to the wheel.

I didn’t actually fall down: it was only my leg touching the back of his bike. I keep riding.

He also wrote: “I’ve got to break [brake] but I can’t avoid crashing against the rider in front of me”

His story is full of query, inconsistency and conjecture. Not saying it didn’t happen, just saying there’s not proof enough there to say to me that it did.

Further – as well as present the facts as he saw them, he’s acted as judge and jury (and pushed the UCI into being the executioner) without querying his version of events; worse than that he cited another example of a similar injury as being ‘obviously’ caused by another disc brake which in turn I think we’re all reasonably clear in accepting wasn’t which degrades his opinion further.

Put it all together – you can still argue about whether discs are a hazard to the peloton, whether that risk is a risk that is small enough to accept, whether the advantages of discs are enough to outweigh those risks, just as we are. That’s all still a debate that will rage. But in the specific question of ‘look what a disc rotor did to my knee!’ I don’t see his evidence as sufficient to convict.

I think it’s pretty clear that most (not all, I know) recreational riders, when considering a new bike purchase, want discs. This suggests that what the pros ride isn’t perhaps as important as some people advocate (as, der… the pros don’t ride discs)

This puts bike manufacturers in an interesting position I think, as the market (us) is choosing bikes that the pros don’t use (or even want to, it appears).

With any good set of rim brakes on a road bike, braking power is limited by tyre traction, not the brakes.

I do wish people would stop spouting this crap. It’s nothing to do with absolute power, it’s to do with how that power is applied and the modulation and control that you can have.

I have a rim braked road bike (Dura Ace calipers on alu rims) and a disc braked CX bike. Put the same slick tyres on them, wind it up to speed and the CX bike will stop far more quickly than the road bike with no lock up.

I’ve never unintentionally locked a wheel up on either although it’s easy enough to do on both bikes if you try.

You can lock up the wheels on a car with drum brakes but no-one says discs are pointless. You always want more braking power than you can actually use (subject of course to that power being contrrollable).

We’ve been saying that for ages crazy-legs but they just aren’t listening.

Yes, it’s also been shown in video on youtube too.

You can lock up the wheels on a car with drum brakes but no-one says discs are pointless.

Drums are more powerful in fact, due to self-servoing. Disc brakes can dissipate heat much more effectively, though, which is why they are used (along with brake servos in most cases even delving back to pre-ABS days). Drum brakes are actually better on the handbrake as this is never servo’d. I used to compete in autotests and people would try and avoid disc brakes at the rear for this very reason (and the fact that there’s not much heat buildup in an autotest!).

It could be argued that the rim (particularly an alu one) is better for heat dissipation, but the reality is “it depends”, and to the pros both systems are adequate. I think there is a perception in some quarters that rim brakes will be inadequate, but they simply aren’t (if they’re good and set up well) for road riding, except for wearing through rims, which isn’t an issue for the pros.

It’s probably worth saying as well, that maximum stopping power (and thus control of that power) comes when the brake pad/surface is up to temperature. In an emergency, a disc does this VERY quickly, whereas a rim doesn’t usually do this in anywhere near as timely a fashion.

I had someone open a car door on me this week, at 24kph and just passing the rear of the car, I still managed to stop before hitting them. A similar situation in the evening just a few weeks before (on my rim braked Kona) when a lady pulled out in front of me, I had twice the stopping distance/reaction time but still had to swerve in front of the car to avoid an impact. In neither situation did I lock a wheel, but came close with the discs.

[Quote]I do wish people would stop spouting this crap. It’s nothing to do with absolute power, it’s to do with how that power is applied and the modulation and control that you can have.[/quote]yeah. You’re right, you might be better off with discs if you don’t have the experience or dexterity to modulate caliper brakes.

You’re right, you might be better off with discs if you don’t have the experience or dexterity to modulate caliper brakes.

I can manage with caliper brakes just fine, thanks. I’m also capable of using downtube shifters and clips & straps.

Same here. Not sure what sort of point you’re trying to make though.

Same here. Not sure what sort of point you’re trying to make though.

The point is that hardly anyone uses them, because newer alternatives are preferred.

Lol.

I doubt that the adoption of road racing discs is going to be ended on the basis of one injury. The leisure market appears to be moving to discs, and manufacturers will want to standardise on one type of brake, so I think they will continue to lobby for their introduction. Pro teams will just ride what their sponsors tell them to.

I’ve been using discs on a road bike for 13 years now, for touring, commuting and winter training and have not had any issues with braking or tyre performance. They work OK. I think there are some issues to sort out for racing use, like compatibility, wheel changes, etc, and the transition period between rim and disk brakes in the peloton will be a bit awkward, but none of that is insurmountable.
Caliper brakes might stay on a bit longer for TT aero reasons.

yeah. You’re right, you might be better off with discs if you don’t have the experience or dexterity to modulate caliper brakes.

So calipers are harder to use and less ‘modulate-able’ than discs?

In breaking news….

More disc brake injuries..

If they are set up badly, or the rider isn’t practising enough.

I mean, this whole thread is about what the pros use. Not what sport riders want to use.

Maybe that’s why everyone is so upset about this. They want discs so they can have one do it all bike, but they also want to look like the pros.

Some pros already have to use massive long and/or negative rise stems to get their position sorted on “standard” frames. Which the head tubes are longer than needed. So why not force them to use discs, that they don’t really need or want.

ghostlymachine – Member
Maybe that’s why everyone is so upset about this. They want discs so they can have one do it all bike, but they also want to look like the pros.

I’m not sure anyone on here (advocate or otherwise) really gives a toss about looking like the pros, nor are most particularly concerned with needing a specific bike to race on. What people are saying is that discs do offer an improvement in performance. I can hand on heart say this to be the case. I sold my Litespeed with rim brakes after riding my PnF (with discs) on road for a good while in spring last year. Getting onto the Litespeed in the summer felt…dangerous, to be frank. I’m sure I’d again adapt to it like I now do with the Kona, but still, there’s no doubting the difference.

Some pros already have to use massive long and/or negative rise stems to get their position sorted on “standard” frames. Which the head tubes are longer than needed. So why not force them to use discs, that they don’t really need or want.

It’s probably worth noting that neither team using discs in the Paris Roubaix were sponsored by Shimano/SRAM so the teams themselves chose to use discs.

I genuinely believe that in a Peloton in which all bikes use discs, that you’d see less riders on the ground after a crash.

Maybe that’s why everyone is so upset about this

The person most exercised about this issue appears to be you.

Maybe that’s why everyone is so upset about this. They want discs so they can have one do it all bike, but they also want to look like the pros.

Some pros already have to use massive long and/or negative rise stems to get their position sorted on “standard” frames. Which the head tubes are longer than needed. So why not force them to use discs, that they don’t really need or want.
I think there’s more than an element of truth to this.

Personally, as per F1, I want the pros to be on bikes that, within reasonable safety limits, represent the pinnacle of the sport.

To draw parallels with motorsport, a lot of the time these days when you read about some Le-Mans winning racecar, the journalists comment about how intuitive and friendly it is to drive, as it’s been made to be driven fairly fast lap after lap, not to extract an amazing qualifying time. This kind of disappoints me.

Similarly, I don’t want to see pros on heavier, slightly slower bikes that are a bit more friendly to ride (i.e. brakes that are easier to modulate when the pros have learnt to brake with the current – fairly powerful if we’re being honest – rim brakes no bother). I don’t want to see them on bikes that are not as fast as one you or I could (given a large chunk of spare money) go out and buy.

Similarly, I don’t want to see pros on heavier, slightly slower bikes that are a bit more friendly to ride (i.e. brakes that are easier to modulate when the pros have learnt to brake with the current – fairly powerful if we’re being honest – rim brakes no bother). I don’t want to see them on bikes that are not as fast as one you or I could (given a large chunk of spare money) go out and buy.

Yebbut, we all spent years riding bikes that were well suited to pro racing, with massive gears and requiring contorted body positions. Those bikes are rather less useful for a social Sunday morning club run.

I genuinely believe that in a Peloton in which all bikes use discs, that you’d see less riders on the ground after a crash.

I doubt it would make much if any difference when a crash happens in a bunch it is like dominoes, you hardly have time to realise what is happening let alone touch the brakes.

Getting onto the Litespeed in the summer felt…dangerous,

Really you must have rubbish calipers. I’ve just ridden my race bike after months on the winter bike with discs and I was pleasantly surprised how good calipers are.

dragon – Member

Really you must have rubbish calipers.

DA7900 on aluminium rims – so no, not really.

Going back to this original incident. I may be a bit dense here but I still don’t understand how this incident is supposed to have occurred. As I understand it, he crashed into the back of someone without falling off. How does his left leg come into contact with someone’s disc on the left hand side of their bike? It seems a strange scenario to me.

Just read an excellent dissection of these crashes on the road.cc site.

No actual evidence linking injuries to disc brakes. One crash didn’t even involve either of the teams riding with discs.

All very strange.

So they should be fine then, not as good as hydro discs but certainly not dangerous.

Really you must have rubbish calipers. I’ve just ridden my race bike after months on the winter bike with discs and I was pleasantly surprised how good calipers are.

+1. Jumped straight from my disc commuter to my carbon rim- braked summer bike, and the brakes were the last thing I noticed (and if they felt different it wasn’t worse).

Why are some people who dont race and dont ride in groups so keen that those who do, use a different technology that adds complexity, adds compatibility requirement, add additional cost, adds additional risk, when no one asked for them and the users dont want them.

If they are so much better you won’t need to argue about it, the users will demand them, no one will buy rim brake bikes and it’ll be the new standard, like say, tapered head tubes, there better so people demand them.

However withh disc brakes whilst I know lots of people spending a lot on new bikes especially now as we are going into summer and they are not buying disc bikes.

I’m not arguing that people should be forced to use them, it’s choice.

Or rather it isn’t, because someone had a crash, decided on the basis of somewhat sketchy if not outright unreliable evidence that an injury was caused by discs, and on that basis has forced the UCI to rule against them. So there is no choice.

In answer to numerous points.

Why do riders want discs banned, unless they think they are unsafe? (This doesn’t make riders right, but surely they’re not kicking up a stink for a laugh?)

Other risks. Motorbikes on the course. They are a different issue, and (arguably) there would be no race without them. There can be a race without disc brakes. And we are talking about introducing a risk unnecessarily, not managing a risk already there and longstanding.

You can always go wide however good your brakes are – the only thing for sure is that the better your brakes are the later you will brake.

I generally don’t buy new bikes, but as someone who has ridden road bikes for 8 or 10 years and MTBs for the best part of 30 years I can’t imagine riding an MTB with rim brakes and I have to this day never considered why on earth I’d need discs for the road. I have no problem with people choosing to ride discs. I wonder whether this issue will come up in club rides?

“Why are some people who dont race and dont ride in groups so keen that those who do, use a different technology that adds complexity, adds compatibility requirement, add additional cost, adds additional risk, when no one asked for them and the users dont want them.” Nail. Head. Surely the key thing is what the pros want, after all they are the most important thing.

“I’m not arguing that people should be forced to use them, it’s choice.” By giving people that choice you are also denying others the choice of being able to race in a pro peloton that hasn’t just introduced technology that is not proven safe (in the pro peloton).

How do you prove something safe unless you use it for a prolonged period, until either you gather COMPELLING evidence of injuries or find that you don’t (which would ‘prove’ the opposite)?

At the moment it’s being declared unsafe on the basis of one distinctly unproven incident, and opinion.

Why do riders want discs banned, unless they think they are unsafe?

Do they? Some do, but is it the vocal minority or is it genuinely the mass opinion?