Originally Posted by
sequoia78
Anyway, seriously, when cross racing began there were no obstacles, and few riders dismounted.
Ahem. I am guessing that you are unfamiliar with this website:
http://www.blackbirdsf.org/cx/
The photos of the guys with fenders are from a 1921 article by Eugène Christophe in which he states, for example:
The beginner imagines that he must stay on the bike at all costs, under the pretext that he will be faster on the bike than on foot. But he often confuses speed with haste, and while believing to be gaining time, he loses it, because he falls or because he damages his machine. One should also not take the opposite course to what I have described, and run like a cross-country running specialist. A cyclocross racer makes use of cycling and running interchangeably, as its name ["cross-country cyclo-pédestre"] indicates.
The above-mentioned website also includes these excellent photos of pre-war cyclocross racing:
