I use "thingie" in the title to not give anyone a false impression of
what I do or don't know.

I'm working with a client who's using one of these in his specialized
bike:

https://www.amazon.com/dp/B01KYKEP2Y...xx_P1400_1000?
tag=dradisplay-20&ascsubtag=c73ee0e485a804ac76001596b2b029f4_S

He's currently using the 250W version, but we're having problems of
insufficient torque -- this is partially due to re-purposing a board, and
we're on top of that part, but I'm thinking ahead (well, borrowing
trouble, in proper engineering fashion). So we thought -- hey! We'll
use the 350W version (that's the one in the link).

The problem is that the 350W version actually has a lower current-to-
torque constant -- it gets its higher power through pulling more current
for the torque, and delivering more speed.

So -- any thoughts on an easy way to gear the thing down? I just
recommended to the customer that they put two chain rings on the crank,
so that they can drive the pedals at one speed and the bike at another.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com