My brother has just signed up to do the Kielder 100. He is intent on improving his fitness levels, and with his Birthday coming up I'd like to buy him something useful. I was hoping to get him a HRM for his mountain bike, preferable one that can do the distance and speed thing too (that's the cadence bit I have found out?) but they all seem really pricey. Almost bought the Polar100 until I read 1 review saying they are rubbish for off-road riding. Any helpful comments appreciated, I am no biker and don't want to waste my money on something that isn't worth it. It'll be some bum grease if not!