Steve and Rich, interesting stuff, and I can believe that raising the gearing might be detrimental. I ride from Portsmouth to London every day, and I have to keep the fuel useage down as much as I can, so I keep it slowish and try to avoid too much throttle work. It makes quite a difference!

I'd still like to know why bikes are comparatively uneconomical (pro rata with cars)though. Actually, I have an idea that it's because the manufacturers mainly sell bikes as toys, and people who run bikes as toys generally don't worry about economy. It's probably also the reason we have to do so many modifications in order to get a bike to last when we ride to the further reaches of the world (no manufacturer other than KTM makes a real purpose-made dirt touring bike). It's probably also why bike cycle parts corrode so readilly when exposed to the weather. If car steel wheels rusted as easily as my Transalp spokes and fastenings there would be an uproar! Please forgive my cynisism, but the bike industry needs a good kick up the bum before it can claim environmental friendliness...... Stig