Belt drive fixed

This post reminded me that I was admiring one of those Treks a couple of weeks ago, and think they are a fantastic idea. I understand that chains are something like 99% efficient. Has anyone done an experiment to see how efficient belt drives are?

it's not hard to able to see that belt drive are plenty strong enough for human powered machine, if it can withstand a motorised machine, it defintely can deal with weak human legs.

expect maybe Chris Hoy, he might able to snap it.