Checking In on Electric Trike Conversion

About a year ago I finished the second iteration of the torque arm for the electric motor on Lisa’s HDQE. Since that time the trike has seen about 500 miles including a trip along the Trail of the Couer D’Alenes. I recently removed the motor to see how the new torque arm is doing. There is some wear in various places but overall it seems to be holding up well.

My biggest concern was that the stainless steel pin would elongate the hole in the aluminum torque arm in which it rests. I see very little wear where the inner diameter of the pin meets the torque arm so that doesn’t appear to be an issue. However the outer shoulder of the pin seems to be carving a chunk out of the torque arm. This is happening because the shoulder protrudes slightly beyond the suspension arm. This wouldn’t be so bad except the end of the pin is very close to the brake rotor. In fact you can see where the pin is beginning to cause a very light scratch on the rotor. It looks to me like the wear on the torque arm slot is pretty much finished and the impact with the rotor is minimal, I don’t see this as a problem moving forward. If it does turn into a problem I’ll need to shave a few mm off the end of the pin.

The picture below shows the wear on the slot in the torque arm. The bottom arrow shows where the bolts for the brake rotor have been worn. I think this was caused by the previous torque arm when it failed.

Top arrow shows wear from pin, bottom arrow shows wear on brake bolts
Stainless steel pin that torque arm fits into, shows wear marks in shoulder
Pin comes very close to brake rotor

Another issue is that the torque arm is rubbing on one of the suspension arms. We knew about this problem, I had to do some filing to get things to seat properly after Terry handed the final version off to me. Maybe I need to file a little more because it’s obviously rubbing but I don’t think it’s causing any real damage. And I’m at about the limit of what I can file down, the tolerances are super tight in this area, so I think I’ll leave it alone.

Shoulder of pin protrudes slightly beyond suspension arm
Where suspension arm rubs torque arm (top arrow), marks on rotor from pin (bottom arrows)
Where torque arm rubs suspension arm

A final issue is that there appears to be a little more wear on the drive tire. It’s not enough to be of concern but next time I fix a flat I might swap the fronts just to even things out a bit. Maybe I need to re-adjust the toe-in, I’ll do that too. But my money is on Lisa’s affinity for throttle.

More wear on drive tire (right)
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