When it comes to riding through the woods with rocks, trees, and other natural things that can shred light weight fabric. Some have this confusion about what they should wear while flying through the woods.
This is where we meet with Rule 18: Know What To Wear. Avoid Kit Confusion.
No baggy shorts and jerseys while riding the road bike. No lycra when riding the mountain bike (unless racing XC). Skin suits only for cyclocross.
This has become a wee bit of a pet peeve. Maybe it was the roadies who brought it over from the road biking world into mountain biking and everyone thinks it was a good idea because they saw Nino Shurtner hammering like Tomes of old. Yet if lycra off road is such a good idea why don’t you see dirt bike racers in say Paris Dakar wearing it?
We have all seen the Tour De France and the crashes they do on paved roads. If crashing on paved road while wearing essentially skin tight easily shredded fabric can almost destroy lycra. Imagine what a good crash in lycra can do on a mountain bike.
Using the motocrosser example they don’t because it will be worse then the road biker pic. May as well find a giant cheese grater and slide that it would have the same effect if they crash at high speed. And the huge bonus being medical attention would be easier to get. And I have heard many times the argument put forward that it helps with wind resistance. You can’t be serious.
Aerodynamics? When was the last time you heard of Trek using a wind tunnel to get one of their mountain bike stars faster? Never. Aerodynamics is an issue facing roadies and not one mountain bikers face.
Unless you are racing in a XC race there is absolutely no reason to only be wearing a thin pair of lycra shorts. When you consider all the possible ways riding singletrack one can destroy lycra the only acceptable choice is baggy shorts over lycra. And think of how much longer your lycra will last with baggy shorts taking the blow.
And we are not savages in mountain biking and we do have some rules because we are civilized. And in a civilized gathering of mountain bikers post ride one cannot look casually relaxed with a beer in hand in lycra.