TwoTired
New member
My 7 speed ebike with a BBSHD and shift sensor worked OK down shifting, but when upshifting the motor turned back on before the shift was complete with the smaller sprockets. I think this happens because upshifting is done by spring action and so is slower than cable pull.
As far as I know the off interval of the gear shift sensor is not programmable so a few weeks back I decided to try something like the front freewheel system (FFS) Shimano made back in the 1970s. Shimano used a rear freewheel with increased friction that kept the drivetrain moving so shifting can be done while coasting.
The BBSHD has a chainring freewheel so all i needed to do was increase the friction in the rear freewheel. To do it I used a piece of cardboard wedged between the sprockets and the chain guard (see photo). The cardboard interfered with the large sprocket but I was careful not to use it during the first 20 mile run. It took a while to get used to shifting this way. Stop pedaling, shift and resume pedaling is something you just don't do with a BBSHD. Shifting went smoothly, without nasty sounds coming from the drivetrain. Since then I've replaced the cardboard with a piece of flexible plastic pushed farther down so I can use first gear.
To test the system, all anyone has to do is wedge a piece of cardboard as in the photo. For those who try it and decide it works for them I have set a web page with instructions and photos for a more permanent system at http://lce.org/ebikes/ebike-shift.html .
As far as I know the off interval of the gear shift sensor is not programmable so a few weeks back I decided to try something like the front freewheel system (FFS) Shimano made back in the 1970s. Shimano used a rear freewheel with increased friction that kept the drivetrain moving so shifting can be done while coasting.
The BBSHD has a chainring freewheel so all i needed to do was increase the friction in the rear freewheel. To do it I used a piece of cardboard wedged between the sprockets and the chain guard (see photo). The cardboard interfered with the large sprocket but I was careful not to use it during the first 20 mile run. It took a while to get used to shifting this way. Stop pedaling, shift and resume pedaling is something you just don't do with a BBSHD. Shifting went smoothly, without nasty sounds coming from the drivetrain. Since then I've replaced the cardboard with a piece of flexible plastic pushed farther down so I can use first gear.
To test the system, all anyone has to do is wedge a piece of cardboard as in the photo. For those who try it and decide it works for them I have set a web page with instructions and photos for a more permanent system at http://lce.org/ebikes/ebike-shift.html .
