My question about gear ratios was really directed at knowing the ratios in gear inches available. For example, my Merc has ratios of 45, 60 and 79 on its larger chain ring delivered through the SRF3 hub. Knowing the overall range of the hub in question as provided on the website, doesn't tell me whether I will be able to pedal it up the local hills. That is all a matter of the ratios available through the front and rear pulleys and the internals of the hubs. Giving the final ratios from pedals to wheels is helpful.
By the way, I'd have thought belts of the type that operate camshafts in car engines would vastly out perform traditional straight cycle chains. The camshaft, fuel pump and water pump in a VW diesel like mine, all driven by a toothed belt consumes several horsepower - about ten I am told. They get replaced between 40 and 60 thousand miles, or about a thousand hours - call it 10,000 hp/hrs. That kind of technology ought to outlast most bikes, I'd have thought. I couldn't deliver that kind of effort in the rest of my life, riding at I do at about 1/10th of a hp. It would take me 100,000 hours to deliver all that energy. That's 600 weeks solid or eleven and a half years of non-stop riding at 12 miles an hour. I'm not an engineer, but even if I'm out by a factor of ten which I am not, the belt is a good option.
Last edited by EvilV; 10-22-08 at 12:04 PM.