Strange problem: power through one pedal only

[Madiba]

I recently crashed my electric bike (Cyclotricity Stealth 1000W). I have just started cycling again (after many weeks off nursing my broken pelvis). The cycle seems okay, but I notice that the motor only functions when I push down the right pedal (that is, the motor keeps going on and off, depending on whether I push the right or left pedal).

Any ideas?

 

[Benjahmin]

Did you, by any chance, break the left side of your pelvis? The spec on the Cyclotricity site doesn't say but I'm guessing the bike is a torque sense. In which case, if you can't bear down on the left side as much as the right, the motor won't respond as much.
Shooting in the dark here.

 

[Madiba]

Blimey, yes the left pubic rami (little bones at the bottom left of the pelvis). Which means, yes, my left leg is a bit weaker, but on the bike this makes little difference and I am pushing through pretty well with both. However, I will push ready hard with my left leg tomorrow (pain permitting), to see if this has an effect.

 

[Fordulike]

I recently crashed my electric bike (Cyclotricity Stealth 1000W). I have just started cycling again (after many weeks off nursing my broken pelvis). The cycle seems okay, but I notice that the motor only functions when I push down the right pedal (that is, the motor keeps going on and off, depending on whether I push the right or left pedal).

Any ideas?

You might have damaged the PAS sensor disc on the bottom bracket.
If it has been forcefully moved out of place, it might be rotating a bit wonky or at an angle. Then the disc might only be activating the receiver intermittently , causing the on/off symptoms you describe.

 

[Madiba]

Thanks. I am going to take it in to a very good cycle repair shop in Sheffield tomorrow most likely (if the problem persists), so will bear that in mind.

 

[Madiba]

Actually, the bike does not appear to have a PAS sensor disc.

 

[Madiba]

Oh wait on, it does have this disc. You can tell I am new to this electric bike malarkey.

 

[Fordulike]

Oh wait on, it does have this disc. You can tell I am new to this electric bike malarkey.

Both the disc and the sensor with the cable should be nice and clean.
Check that as the pedal rotates, the disc passes the sensor in an even and uniform manner, and that it's nice and close but not touching the sensor.
Also make sure the disc is nice and secure. If the plastic is cracked, it may be moving about as you pedal.

 

[Madiba]

Well, I fiddled around with the disc and sensor last night. I am not sure whether that had any effect, but today the motor is working perfectly, no stopping and starting. So, all sorted. Thank you guys for all your input.