I am pretty much resolved to purchase a staton crank or gear-drive kit.I would as I have said before LOVE a frame mount kit.I found this which is about half the price, I hear these motors are very good, looks like a 142 f.Anyway, will this gearbox hold up ?? I would be putting around 100-150 miles/week on the bike in the desert here in az, all street stuff commuting.I hear the gear box/belt drive is the weak link.How often do they have to be replaced,etc........Thanks