Why no disc breaks on road bikes?

[gaz]

the thing to look at is the background of racing bikes and the uses of disc brakes.
Racing bikes are designed and made to race. Parts are lightweight and anything that isn't needed, isn't put on the bike.
How many times, on average, does a cyclists need to stop during a race? the only advantage discs have over rim brakes for a racing situation is stopping. When all racers need to do is scrub speed off occasionaly, which the canti's are great for.

Disc bakes are known for their stopping power. Great on MTB's and trials bikes where you may have to stop quite quickly. Due to their position they are also less affected by mud and water.

I'm looking for a new commuting bike. i've got to stop a lot en route and sometimes in heavy rain. discs with drop bars is what i'm looking for

 

[MacB]

I'm looking for a new commuting bike. i've got to stop a lot en route and sometimes in heavy rain. discs with drop bars is what i'm looking for

Well I'm awaiting my Pompetamine frame and forks, Avid BB7's, headset, stem, bars - I already have the hub gear disc wheelset, chainset, saddle, seatpost, rack, etc - still to bite the bullet on a SON28 front disc wheel and dynamo lights, and I'm there.

The plans for a disc brake road bike continue, as it would be a fairish weather beast I'm undecided between Burls titanium or Roberts steel. The temptation is for an Alfine 11, dynamo front, titanium for night riding and foul weather, plus a lightweight steel derailler for day rides and nice weather. Just struggling to justify two nice bikes rather than one, I'm sure I'll manage, but then I need to justify it to the external powers that be....not so easy

 

[John the Monkey]

When all racers need to do is scrub speed off occasionaly, which the canti's are great for.

If you're talking about Cross here (you mention cantis, so I assume you are) disks would, in theory, allow you to carry more speed into the corners - as I said in posts passim, in sports with lapped courses, improvements in brake technology = faster lap times. Cross happens on lapped courses that are muddy (often) ergo I can see disks being significant.

For road racing, very much less so (assuming current technology &c)

 

[PaulSecteur]

I really didnt expect this thread to go more than a page!

All usefull input and thanks for replying.

Paul

PS- I was genuinly curious as I thought discs were superior. Im sorry if some of you took it that I was insulting your rim brakes.

 

[fossyant]

Callipers on road bikes are powerful enough to put you over the bars anyway, even old quality 'single' pivots......

Road bikes are about design and beauty - you can't stick fugly stuff on them..... OK with MTB's as they aren't 'pretty'.....

 

[xpc316e]

I recently bought a second-hand MTB with Quad QHD1 hydraulic discs, and one of the main reasons I got this particular model of bike were the reviews of the brakes. I have not been disappointed with them: they offer fantastic power, ease of use, and tremendous modulation. I have a road bike with well set-up Ultegra brakes and recently frightened myself when descending a very steep local hill. I found that the brakes were nowhere near as effective as I would have liked when I tried to stop from over 30 mph while still going downhill.

I will not be at all upset by the arrival of road bikes with decent hydraulic disc stoppers. I did have a nice recumbent that had Magura hydraulic rim brakes, and they were also very good indeed. Once you experience the degree of fine control offered by hydraulic actuation, there is no reason to go back to awful Bowden cables.

 

[dellzeqq]

The weight argument is a bit of a red herring, I did some rough calcs on differences using Avid BB7 with 160mm rotors as a comparison. Including accounting for heavier frame and forks I couldn't get more than about a 700g weight penalty. This is without allowing for weight savings on rims not needing a brake track. Also they claim that pro riders already add weight to their bikes to reach the required limit.

700 grammes! Having spent an extra fifty quid to get Dura-Ace pedals because they're a few grammes lighter than Ultegra???!!!

 

[HJ]

linky

Ah but are they STi compatible? That just shows them being used with chicken levers...

 

[HJ]

I'm looking for a new commuting bike. i've got to stop a lot en route and sometimes in heavy rain. discs with drop bars is what i'm looking for

Best get a Genesis Croix de Fer

 

[gaz]

Ah but are they STi compatible? That just shows them being used with chicken levers...

They where designed to work with drop leavers

Best get a Genesis Croix de Fer

Might i add i want a hub gear. The day one is on my list