I think I may have uploaded these before but I can't find them so here they are again. I suppose if the powers that be reckon they're worth it, they'll make them a sticky.
The first is a chart showing wheel rpms in 5 mph (8 kmph) increments for different wheel sizes. Say you wanted to go 20 mph and you have 26" wheels on your bike. The table says the wheel rpm is 259, so you can use that to help you decide the sprockets you might need.
The second table has to do with friction drive. What matters in fiction drive is the diameter and rpms of the driving spindle or wheel. As long as there is no slippage between the driving and driven wheel, the size of the bicycle (driven) tire doesn't really matter. Say again you want to go 20 mph. If your friction drive setup uses a 6" scooter wheel on top of the rear tire, you'll want that to turn at 1121 rpm to get 20 mph - jd
The first is a chart showing wheel rpms in 5 mph (8 kmph) increments for different wheel sizes. Say you wanted to go 20 mph and you have 26" wheels on your bike. The table says the wheel rpm is 259, so you can use that to help you decide the sprockets you might need.
The second table has to do with friction drive. What matters in fiction drive is the diameter and rpms of the driving spindle or wheel. As long as there is no slippage between the driving and driven wheel, the size of the bicycle (driven) tire doesn't really matter. Say again you want to go 20 mph. If your friction drive setup uses a 6" scooter wheel on top of the rear tire, you'll want that to turn at 1121 rpm to get 20 mph - jd
