Yeah and that's why I think these particular rules shouldn't change. Everything else has evolved but lets keep one part of the bike which can tell a bit of the biketrials history. It's a stock bike, it's how the rules have been since the very beginning so why change them. Meh, I'm a conservative when it comes to this sport. If I were to ride proper UCI/BIU comps, I wouldn't complain about this rule. As long as it applies to everybody, it's fair. Also, for the amount of money people spend on comps, I doubt getting a spare comp-legal rear wheel, sis shifter and mech is a big expense. Some things just shouldn't change