tandem cycles

[Oldboy913]

why is it that the sproket wheels get smaller towards the rear?

[RATTER15]

Well the bigger the gear on the wheel, the lower the gear, if you had a very large gear wheel on the rear wheel, you would be peddling like hell to get anywhere! a smaller gear wheel is basically a higher drive gear. same as the difference between gears in a car, you wouldn't want to drive around all day in 1st gear.