Originally Posted by
JeffOYB
I'd think the most impt things for racing cross are first the fit then the tires. Once you have those two things, what's next? Does a better frame help you move up in places? I could see something like the frame having more of an effect on the hour-race dudes. They are out there a long time and subtle things could really add up. Could moderate Masters types also feel the difference of a better frame? Maybe in frame design you start to get more into preference rather than outright works better.
Would the next significant thing for race results be going from a 18/19-lb bike to a 15/16-lb?
???
Answer: 6.7%*
My experiment was with the purest form of cycling: Velodrome. I went from a decent steel bike (~20lbs) with normal components to a new aluminum track bike with some top shelf components (UCI min weight: 6.8kg)
The difference: It was literally like shifting gears. The weigh and responsiveness were like shifting from a 16t cog to a 15t cog.
A lot of it was weight and responsiveness. Track is such a tight discipline – the differences were easy to consistently see and measure.
For CX, the same applies – weight, acceleration, responsiveness. I think the geometry has to be pretty far off to cause a problem as people are pretty adaptable. But weight and components can make a big difference. Its just that, not riding in a paceline, its hard to see where the bike will cause me to get dropped or loose significant time.
Material:
I like steel, but find it too heavy and noodly to be effective for racing. It’s a nice ride though.
Aluminum: Stiff and light, I like racing with it. I use my tires and seat post to take a stiff responsive aluminum frame and make it cush and comfortable
Carbon: Stiff and uncomfortable used to be in fashion, but these days it’s all about vertical compliance and lateral stiffness. Makes for a nice race bike.
I don’t find carbon to be faster than aluminum per se, unless the carbon is designed to give you a steel like ride (which is hard to do with Aluminum). Still, brands like Salsa say their new AL bikes are as stiff and more compliant than their previous generation Ti bikes.
*And then there is this measurement.
Road bike vs gravel bike: 6.7% faster
Old bike vs new bike 10.1%