Disc Brakes - First Look

[MichaelB]

....
It has been proven, they give little or no advantage in dry conditions. .....

Do you have a source ?

They don't always race in the dry.

I haven't seen anyone do a proper REAL WORLD comparison to show/quantify the real advantage or not. There are some wind tunnel tests that are one-sided, innaccurate or do not actually reflect real world riding. Wind tunnel tests without a rider mean nothing. As most people know, wind is not always in one direction for a single rider, and then there is the effects of the peleton.

All of the naysayers tend not to have ridden them, so there is lots of supposition and long bow drawing.

Mind you, if you don't like it, then that's fine. I do, as they are at worst pretty much on par, or miles better. They are no worse at all.

[Calvin27]

It has been proven, they give little or no advantage in dry conditions. It is all about feel and product tech sales.

What people feel is pretty important. It is usually linked to performance characteristics of some sort - it's just that most people are not educated on the matter enough to understand how to translate the 'feel' to an actual diference. people pay good money for feel, I wouldn't say it is game changing but neither are things like 'compliance' they just make life easier.

Back on topic. I like the look of the campy calipers, very clean design and the flat mount is pretty flush.

[hedgehog]

peloton fork flexes under braking,no load at all.

i'v done the same on some of my bikes,i even took the tire of one of them.
all the forks flex,i have in the past done some heavy breaking down descents.
i can only see advantages in disk brakes,i chose mountain bikes because of the disks.
i'm now thinking of a road bike,pedaling against the wind is more easy.

[softy]

I never said they were worse.

I agree in the wet they are far more consistent, but i have seen a couple of vids on the net testing them. GCN did one and nothing was in it. I saw another, can't remember the name, but also very little in it. Where discs fool you is they are lighter in the hand so they appear to by more powerful.

What i see as the big negative is to build a "race roadie" you need to build a whole new bike, you can't carry any component over. The wheels are going to be heavier, and wind tests have shown at certian angles they create more drag.

I have some pretty nice roadies now, with ultra light wheels, just to stop a wee bit sooner (very wee) i just can't warrant the expense of a 10+k bike.

[Duck!]

Where discs fool you is they are lighter in the hand so they appear to by more powerful.

There's no foolery at all; hydro discs are more powerful, and better-controlled than cable brakes. The kicker is tested using a single finger on the brake lever; the hydros are streets ahead of the cables & only a whisker behind any brake with full-hand application. The vastly more efficient transfer of the rider's effort into the brake means you can achieve the same performance for a lot less input effort.

The wheels are going to be heavier

Not necessarily. The rims are lighter due to not having the sidewalls beefed up as much to accommodate a sacrificial braking track. The brake rotors, especially if composite steel/aluminium construction don't add much weight at all, and nor are hubs particularly heavier.

[softy]

Just because you are using hydralics to to make the application of less hand force to the level of braking, doesn't mean the bike stops quicker.

A disc brake front wheel has far more force (rotational) applied through the spokes when stopping, why you can't use radial construction and need more spokes. We will see if they can make the wheels as ultra light as a set of Reynolds MVT ul 32 at 1040grams?

The wheels may be able to be deep dish and more aero due to not worrying about the brake track but that is the only advantage i can see.

I still think we are talking about tiny braking advantages for spending a heap of money.

[hedgehog]

uci ready to change the 6.8kg weight limit.
by cyclingtips.
interesting article.

[RonK]

Team Roompot-Oranje Peloton seem to have been a little disingenuous about their adoption of disc brakes. Or perhaps the "issues" have been greater than expected.

Before the season started and again in the video I posted it was stated that the team would use only bikes with disc brakes.

But in the Dwars door Vlaanderen Roompot's Jesper Asselman in the breakaway group was clearly riding a rim-braked bike .

So much for Roompot's committment to discs.

[RonK]

Hmmm, just noticed Roompot's Huub Duun in stage 3 of the Volta is also using rim brakes.

[Thoglette]

I still think we are talking about tiny braking advantages for spending a heap of money.

And the irony being the guys racing are those least likely to be in the rain with pyscho traffic - where I can see the benefits of discs.