Hi i'm new here , not sure if anyone else has had the following issue.
i fitted bafang HD motor to my On One Fatty (a 2014 fattire bike) . Due to the miss-alignment of the chain wheel, using the stock bafang chain wheel, I could only use a few of my highest gears. Test rode the bike and even with just he high gears it gave me loads of assistance, plenty to get up the big hill to my house in Nelson bc.
But as I wanted full gear use, I ordered the Lekkie 40T replacement chain ring, also fitted their replacement motor cover and followed all the instructions including filing down part of the motor housing to make it all work correctly. So that solved the alignment issue but I figured I could still do with lower gears, so I fitted a 11-46tooth replacement cassette, along with new derailleur, shifter, gear cable and new chain of the correct lengh for the new set up. So i'm now running a 40:46 ratio in my lowest gear.
However I now seem to have very little torque assistance when I test ride the bike. on bike stand the motor is kicking in and seems to be working. But when I ride the bike I get very little assistance when I pedal ( if any) , but when I press thumb throttle at the same time I do get a bit of assist but still seams really weak.
So what did I do wrong. has anyone else had this issue. I wonder if I maybe put in too much or not enough grease? it's like a sensor or something isnt working. So maybe I got grease on the contacts I saw near the pinion cog when I had it apart?