Belt drive fixed

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.

Human legs are not weak. Human legs can put out more lb/ft of torque through a bike than a performance car can generate.
Although I am not doubting the belt is strong enough to cope with it :-)