Derailleaur as Chain tensioner

[jototojo]

Hi guys,
I thought of an idea of using the rear derailleaur of a regular 21 speed or something bike as a chain tensioner.
Could it work?
Somebody did it???
Thanks.

 

[wheelbender6]

Yes. It works well. The derailleur is just a little heavier than a single speed tensioner.

 

[jototojo]

But the chain fits on the sprocket of the derailleur??

 

[Nashville Kat]

Tension the pedal side with the derailleur- you can even add some gears!

then if you have clearance with a cruiser frame and your sprocket is not too large in the back, you realy dont need a tensioner on the motor side- just adjust it back or forward in the dropout.