View Single Post
Old 02-11-2019, 05:17 PM
Mark McM Mark McM is offline
Senior Member
Join Date: Jun 2006
Posts: 7,829
Originally Posted by Bonesbrigade View Post
Almost all the world tour teams are on disc this season.
I guess that's what the bike company marketers want you to believe (and it looks like you've been drinking the Kool Aid). But when this was discussed a few weeks ago, it was found that the majority of world tour teams are not using disc brake bikes (10 out of 18). Of the other 8 teams, 4 are using a mix of rim and disc brakes, and only 4 are using disc brakes exclusively.

I suspect that it has nothing to do with extra aero drag, and the reason racers use rim brakes instead of discs is similar to why they use tubular tires instead of clinchers:

By many measures clincher tires give a performance advantage over tubulars because clinchers have lower rolling resistance (and also often lower aero drag as well),


The performance advantage of clinchers over tubulars is very small, and because clinchers are more prone to pinch flats and can't be ridden as fast when flat, the risk of losing a lot of time due to flat clinchers is of greater concern than gaining a little bit of time due to their lower rolling resistance.

By many measures disc brakes can give better braking performance than rim brakes, by giving more consistent brake performance over a wider range of conditions.


The time gained due to the braking performance of disc brakes over rim brakes is very small, and because disc wheels are slower to change and disc brake wheels have more interchangeability issues, the risk of losing a lot of time with disc brake wheels in case of flat tire or other wheel problem is of greater concern than gaining a little bit of time due to their more consistent performance.
Reply With Quote