I am considering fitting an 8Fun motor to my tandem. I would be interested in knowing what's invoved in fitting the movement sensor before going ahead. Is it easy?

 

Another concern is the length of cables: I assume it would be simple to extend as necessary.

I take it you mean the rotating pedelec sensor? These fit onto one side or the other of the bottom bracket, quite easy to do. With a tandem the best place is probably on the front bracket, this will dictate where the controller and battery will be located unless you can extend the wires.

 

The cables from battery to controller to motor should be kept as short as practically possible. Normally the battery to controller with be easy as these two items tend to be in close proximity of each other. The motor cable length will depend on where you intend to mount the battery and controller and if its front or rear wheel drive.

It's dead easy as long you use the thin sensor with magenets. Some of the older kits used an optical sensor that was much thicker and on most bikes there isn't room for it without further mods. The magnetic ones look something like these ones:

PAS--Pulse Padel Assistant Sensor - BMSBATTERY

1:1 assisant sensor for bike [bH-CG001] - $1.50 : EV Assemble, All for Electric Vehicle!

Hi OTH,

Hope I am not trying to teach my granny how to suck eggs here:o

 

You will need to remove the crank arms and bottom bracket to fit a pedal assist sensor.

 

The non moving part of the sensor with metal ring is normally sandwiched between the bottom bracket shell and the bottom bracket, the rotating disc part just slides on between the crank arm and bottom bracket and should be fitted with the arrow pointing the direction of rotation.