I have one of these as well as road bikes. Up until today the bike has been fine. The problem is it is 'slipping'. I have stripped it down and checked everything, re-greased etc... The pedal end is no different to a standard road bike with bearings. That is turning ok and transferring to the front fly wheel, but there is still some slipping. The only thing I can think that might be the problem is to do with the resistance setting/mechanism? Any advice/solutions please.