weeksy – Member
Surely if you’re a chunk

Don’t even go there…. 🙂

In MTBing generally, when trying to go fast, a huge amount of energy is expended accelerating after having to brake for something. Particularly true on windy twisty XC courses. Heavy wheels make a huge difference in this situation. Much more so than when simply climbing.

Do you have proof/evidence/studies of that or is it just your opinion?

I did some calculations once. It’s pretty easy to work out how much extra energy larger or heavier wheels require to get up to speed. The only subjective part is estimating how many times you brake and accelerate during a race. And that of course depends massively on the course and how you are riding it. At a Gorrick for example where it’s flat and you have to keep a lot of speed in the singletrack, there can be a lot more late braking and stamping on pedals than somewhere you are settling into long climbs at threshold.