Mid-drive Electric
Discussion
Most of the mid-drives I have seen have a freewheel built into the crank. No need to pedal constantly. You would, however, need a throttle to keep the motor spinning as the usual assistance will cease when pedaling stops.
With regard to cadence, the popular 8FUN BBS mid drives have a max crank rpm of around 85. I think they mostly come with a 46 chainring which cannot easily be changed.
The usual "take-off" procedure for a mid-drive would be to start in a low gear to keep the motor spinning fast then change up through the gears. The motor might not like starting off with your proposed 20 tooth rear cog, particularly on a hill.
If I were you I would get onto the "Pedelecs" forum and search "mid drives".
I've just built a rear hub type ebike. The forum was a great help.
http://www.pedelecs.co.uk/
With regard to cadence, the popular 8FUN BBS mid drives have a max crank rpm of around 85. I think they mostly come with a 46 chainring which cannot easily be changed.
The usual "take-off" procedure for a mid-drive would be to start in a low gear to keep the motor spinning fast then change up through the gears. The motor might not like starting off with your proposed 20 tooth rear cog, particularly on a hill.
If I were you I would get onto the "Pedelecs" forum and search "mid drives".
I've just built a rear hub type ebike. The forum was a great help.
http://www.pedelecs.co.uk/
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