Question: do jockeys have to be a certain weight?
Answer: Jockeys must be light to ride at the weights which are assigned to their mounts. ... The weight of a jockey usually ranges from 108 to 118 lb (49 to 54 kg). Despite their light weight, they must be able to control a horse that is moving at 40 mph (64 km/h) and weighs 1,200 lb (540 kg).