Originally Posted by
Doge
USA Cat 3, 2, 1 and International (kids < U17).
Here is an example you can move through the fluff and see where / how the kids are riding. They typically slow on corners (using breaks just like the 20 posts before mine talk about using breaks) and jump out. They do have 52X16 gear restrictions.
I don't know about Belgium, but USAC does not specify gear restrictions by gear combinations. USAC suggests 52/14 as the maximum Junior gear, but the letter of the law is the 26' rollout (road, track is different). Wheel and tire sizes vary. The smart Juniors have their rollout correct to within 2-3mm. I measure them twice to be sure, but after that if I recognize them and they roll out that close again, there's no need for a second check. I've had riders give up 1/4 crank's worth of rollout, which can be 2-3 feet. Do your son a favor and dial in his rollout.