BBS02 very stiff and generates power when bike rolled backwards

[drbenjamin]

All
Thanks to all the helpful posts here I regreased my BBS02; opened it all the way, cleaned out old grease and put Mobil SCH100 on the helical/nylon gear and the pinion/secondary. It seemed to go well, the motor is a little quieter. Went for a 14 mile ride w/ no problems. However, the bike now has a lot of resistance when pushed backwards and generates electricity (connected tail lights go on even when battery is disconnected). The pedals themselves freewheel backwards w/no trouble, it’s just sponning the chainring backwards that causes this. Any ideas as to what happened? I didn't do anything to the interior of the nylon gear as I know it's a one way clutch and greasing it can make it slip. I presume it is installed correctly as the motor works fine for forward motion. The bike definitely didn't do this before the teardown, and neither of my 2 other BBS02 motors does this.

Thanks!

 

[drbenjamin]

OK, following up here. I don't know how it is that I've used these motors for 5+ years and never noticed that they generate electricity when rolled backwards - I understand that a motor is also a generator but I thought the controllers in these prevented regen. At any rate, my other motors also light up the tail lights when I roll the bikes backwards and when I put them in identical gears the resistance is not so dramatically different. One still does seem to resist backward rotation more than the other 2, but not by a lot.
Not sure if it's worth reopening it to check on why.

 

[fechter]

That's normal behavior for a BBS02. Going backward, the freewheel clutch allows the motor to spin, which will generate power.
The amount of resistance will depend on the load from the tail light. If you disconnect the lights, the resistance should be less.