Video: Get Your XC On In Nove Mesto

 well to be fair there are rollers that require you to anchor your bike , as mtbdude explains ^, and there are trainers on which you simply put yout bike and pedal. The first cathegory gives you the option of increasing the intensity of the training, and are more expensive. It's a chance for both the trainer and bike manufacturer to put on display more than just the rider's racing kit .

I remember seeing a photo from one of last year's DH races , from one of the top team's tent ( it may have been Atherton GT ) , and the riders were using 7-8k $ am bikes , with enve parts front to back, just for training on rollers.

 I think trainers are best to use with slick tires without knobs, so another reason for another bike

 Slick tires work a lot better on turbos/ rollers, as well as the gearing being more suitable for a warm up on a road bike since you'll push bigger gears on a trainer than you would riding a world cup XC course

 Gwin could perfectly train on his demo ! haha just NO

 Run a knobby on a trainer and it'll sound like that air raid siren

 I think trainers also wear down mtb tires quickly.

 And vice versa. ..