Racing for lardy boys?

Hello all. Does anyone know of a road bike race or time trial that instead of classifying riders by age, one that riders are selected into groups by weight?

I mean, if this isnt done at the moment, why not? Could have a set of scales at the signing on and finish line to measure both bike and rider. Its something I’d be keen on doing, though its unlikely I’d win unless it was a 200m sprint 😕

Anyway, just thought I’d ask. Thanks.