Some downhillers will were a cup. You get whacked in the coconuts enough times by the saddle, you’ll give it a good long thought. A friend of mine slipped a pedal at winter park and, quite rudely introduced, his testicles to the top tube. The cup discussion came up again. A cup isn’t a needed a feature for me. I ride very low on the bike. About once a year I’ll take shot in the gonads. Usually there is more shock and terror than pain. I have taken the saddle hard enough, to lower abdomen, for bruising. I don’t want to imagine how bad a bruised testicle hurts. I guarantee after you bruise one, you’d were a cup.
If you ride over the rear axle, versus the saddle, you definitely need something to hold all of your manhood up. I buzz my ass with the rear wheel about a half dozen times a season. It’s shocking enough on my bum. I can imagine how terrified I would be if I buzzed my nuts instead. I would probably crash because of the panic. Depending on the boys age, a jock strap and rugged shorts makes more monetary sense than some over priced MTB gear. Personally, I ride utility trousers with UnderArmor compression shorts.
Hey, remember when we used to ridicule people for wearing helmets while skateboarding and biking. Those pansies. Real men don’t wear helmets. Right?