If belts had more efficiency at over 150 watts, we'd almost certainly see them at the TdF. I certainly don't maintain over 150 watts when pedaling my bike. There is a member over at MTB.com, NurseBen, and like all of us he has some pretty specific beliefs about what will and won't work on his bikes. First, he wanted a gearbox with a belt, as he is a long-term fit mountain biker and wasn't concerned about a few watts. Mud kept packing up on his belt and the bike was throwing belts. I also think it kept squeaking. So, then...