*Edited*

I agree with all the comments relating to the journo’s poor braking technique. However, I think he has a valid point as brake / bike manufacturers won’t be able to control how users apply their brakes. Some will use them in short hard bursts that allow heat to dissipate while others will drag them. If dragging leads to fluid boil then it could easily result in accidents.

I know that you can over heat a rim brake and blow tyres off the rim etc. but I think the point he is trying to make is that disk should make the risk of an accident lower, i.e. the chances of being able to boil your fluid should be less than the chances of being able to blow a tyre of the rim.

Road disc brakes: a dangerous solution to a problem that doesn’t exist.

I like this article… Last time I think we had a bit of a barney about whether it was the parts, or technique, then eventually someone noticed that he chose all the parts himself and they weren’t designed for the job. So that’s human error, or human error.

But we still had an argument about whether it was human error or human error.

Road disc brakes: a dangerous solution to a problem that doesn’t exist.

Surely, the argument over disks on road bikes reflects a move from replaceable alloy rims with worn braking surfaces, to nice carbon rims with (shudder) irreplaceable surfaces and questionable efficacy in the wet. Swapping out a worn rotor has to be easier than replacing the rim on a Hyperon Ultra. It’s a solution to a problem that the move to carbon has brought upon us. And lighter rims are always nice 😀 .

a dangerous solution to a problem that doesn’t exist.

what’s dangerous about them?

Roadie: 80kg rider and bike descending at 40mph (17.88 m/s). = 0.5*80*17.88^2 = 12787J

The skinny roadie has nearly 3 times the kinetic energy!

80kg ain’t a skinny roadie … that’s a roadie that would get dropped up most hills )

SCIENCE
The skinny roadie has nearly 3 times the kinetic energy!

My point was that mountain bikers are fat. Nothing more than that. And I’m aware the physics of it don’t add up, but that distracts from my point that mountain bikers are fat.

Funny. I’ve been using disc brakes on a road bike since 2006 and I’m somehow still alive.

Correction…Mountain bikers are fat AND slow.

And lighter rims are always nice

But heavier frames,heavier brake calipers,heavier hubs,higher spoke count and stronger(heavier)lacing patterns are’nt.

Funny. I’ve been using disc brakes on a road bike since 2006 and I’m somehow still alive.

but if you lived in the Alps you’d be dead FACT!

My point was that mountain bikers are fat. Nothing more than that. And I’m aware the physics of it don’t add up, but that distracts from my point that mountain bikers are fat.

No, you said:

I’m not sure about the 1/2mv^2 thing…

80kg ain’t a skinny roadie … that’s a roadie that would get dropped up most hills )

80 kg includes the bike, bottles, clothing, shoes, tube, pump, tool.

shouldn’t that be “and tool” or is it meant as pause… tool ?

80kg ain’t a skinny roadie … that’s a roadie that would get dropped up most hills

Quite handy up some Belgian hills as I recall…

Only cos they are really short. He gets dropped pretty soon on big alpine climbs.

*facepalm

What’s wrong with your face and/or palm?

I thought Indurain was 80kg. Theworry is of course not pros but the lardy have a go brigade like me….

I can’t really see how it can be Ok to sell road bikes where the brakes will fail if dragged. Aluminium rims are a much bigger heat sink

Will the UCI allow discs. Having followed 3 stageaces this year crashes are clal a fact of life. i wouldn’t fancy being onone of those multi bike pile ups with hot discs taking the skin off everyone.

If carbon rims are crap for braking then ban carbon rims or add alloy braking surfaces. The bikes wouldn’t way more as they are all easily getting to the limit anyway

Crashes? I’m still more worried about the 53 tooth ring doing 120 rpm rather than a disc rotor doing 30 rpm.

I wasn’t thinking about the spinning, more the hot enough to remove skin aspect….

I’ve been using mechanical discs on a road bike since 2003. All weather, all year commuting, winter training and a few months touring, which included several alpine descents with full camping kit. No problems. Very practical for a working bike, especially when the filthy winter rim grinding conditions arrive. Having said that, my 11 year old DA rim brakes still beat the discs for feel and full on stopping power.

Never come across anyone using brake dragging as a braking technique for long hills on the road (tandems excepted). Usual road braking technique would be to pump the brakes progressively to scrub off speed when required, and let the bike run (or pedal) in between. Contrary to what some people appear to believe, cyclists have been successfully descending long hills very fast for many years!

i used to use v brakes on my mtb (road and trail use) never had any problems. switched over to discs a few years ago, and they are better, not because of the power, but because of the consistency.
i used to use caliper brakes on my road bike, never had any problems.
switched over to discs a few months ago, and . . . . . im not convinced they are a lot better, although they do continue to work in the wet.
my set up, tiagra sti levers, tektro lyra calipers, shimano deore 160mm rotors, all fettled to the max to give a fantastic solid lever feel, but honestly not that much power.
as someone who has bought, and used them, im not completely convinced tbh.
(with the mtb i was convinced after 1 tug of the brakes)

’nuff said.

Someone suggests that dragging brakes on the road is unusual. Hmm. Maybe on light race bike in a hurry but on a laden touring bike where speed is unwanted you have to. Eg The Devils Staircase road has long drops heading west to the sea. Within a few seconds my loaded touring bike went to near 40 mph freewheeling! I wanted sub 20. Dragging was the only way to achieve this as accelerate/brake didn’t keep the speed down. I still think that discs will be the eventual answer but not yet.
As to an answer with no problem, well maybe, just like we said about suspension, discs on MTBs, more than 10 gears, STI/Ergos etc.

Modern tandems now are moving to disk brakes without issue.

Is that what he is up to, thought he had been quiet round here, be telling us next he has seen the benefit of a helmet as well 😉

My tourer has disk brakes. I’d rather drag them and heat up a rotor than heat up a rim and cause a blow-out.

Had Avid Ultimates with 160mm rotors on my Roadrat for 5 years with no problems, perhaps as I’ve installed, bled and serviced them based on my MTB experience of disc brakes it has been the cause of no issues at all?

I will add that I think that the experience of using disc brakes off road on loose slippy muddy surfaces means small contact tyres on tarmac are a piece of piss to control and not lock up in comparison.

I’ve been over 70kph and and heaved on them and stopped in plenty of time despite being a fat bugger, so can’t wait for road bikes in general to have the kit/mounts to fit them.

Like it are not 2014 will see a load of road bikes with thru axles and hydro discs.

I think the conclusion we can draw from this is that those Aishima rotors are shite.