How to enable reverse chain direction with mid-motor

MrE

1 µW
Joined
Oct 9, 2021
Messages
1
Greetings from Holland.
I am hoping to get some direction for a project I am working on. I am designing a multi-functional road/waterbike. The plan is to use a standard mid-mount e-bike motor for pedal assist on the road as well as on water.  An angle gear will be used to convert the pedal/chain motion and drive axle to boat prop.
This is my challenge...when in water-mode I want to be able to reverse the vehicle so I need to reverse the chain/prop direction. I recall seeing a video of the BBS02B, when pedaling in reverse this did not move the chain due to the freewheel in the main chain wheel. The BBS has my preference due to the compatibility with standard frames, easy install, power and throttle option.
I can think of a few options to discover (disclaimer: electronics and e-motor mechanics is not my strongest point :))

1. Change/modify the freewheel so the chain direction can be reversed by pedaling backwards. Is there a kit available or directions how to do this? Something tells me that moving the chain backwards will conflict with the assist mode (using the throttle), or would this work if I set the assist to 0 and not use the throttle when reversing?

2. Option 1 combined with a reverse switch? Is it even possible to reverse the direction of these type of motors via a switch or programming via computer? Or does this require a special type of controller/motor combi?

3. Buy a different type/brand that does allow for chain reversing. Recommendations are welcome (750W, 48V, 17.5A)

Much appreciated!
 
G'day MrE, greetings from Australia.
Unless you're set on using a BB mid drive, the setup I have on my chopper might give you a new idea.
chopmid1.jpg
That's a small geared hub motor with 2 sprockets. 1 from the pedals, 1 to the rear wheel.
View attachment 1
The sprocket nearest the motor is a fixie to the wheel, the outer one is a freewheel to the pedals.
The freewheel acts as a locknut for the fixie since motor torque tries to undo it.
You could use a direct drive hub motor since geared motors can't drive in reverse, & a fixed rear wheel sprocket. Reverse the motor, the wheel runs in reverse.
No more drag than a standard direct drive hub motor in wheel setup.
Only problem you'd have is that the pedals would drive backwards in reverse.

AussieRider
 

Attachments

  • chopmid2.jpg
    chopmid2.jpg
    370.8 KB · Views: 515
Back
Top