KCvale, while that is a good idea, it doesn't always apply to all bikes sos it's an "if ya can" thang
I agree completely bud ;-}
If you have frame interference due to a short frame and/or low motor mounting you have no choice but to add something in there to re-route the chain path.
But as far as I am concerned, anything in the
drive chain path is a bad fix.
That chain is in constant motion, and noting beats sprocket to sprocket for reliability, wear and strength.
To me, sizing the drive chain to fit perfect with no tensioner (if it can be) first, then messing with the seldom used pedal side chain is the way to go.
With the right combination of chain links and motor mounting you don't need one on either chain like my current build.
At first I just threw in a link pair to the pedal chain to make it longer and put the tensioner on that side.
But it is still a big ugly chunk of metal with a plastic moving part. At least on the pedal side wear, mounting and alignment are not a big factor.
For this situation however all you need is a $1.99 Half-Link on the pedal chain.
The drive chain has about 1/4" of slack with ~25 miles, the pedal chain around 1/2 to 2/3" of play.
As the drive chain stretches from the constant use you just move the wheel back when it gets too sloppy. The pedal chain has slack to spare.
Just my 2¢ ;-}