Check your rims...

[IggyBBR]

In all my years of mountain biking, I never experienced this till now, while wiping down the wheels I noticed a stress cracks on a few spoke holes. After closer inspection, the marks are on all along the drive-side on every spoke hole. Could be from the extra (torque) pressure that the motor are applying to the parts on the bike (now I just realize, I need to check the frame on that side too). Currently sent the wheel back for warranty inspection and replacement.

 

[Mtl_Biker]

Wow! What bike is that on?

It could be from the motor torque but I wonder if maybe the spokes had been set much too tight. Please let us know what the outcome is. Bummer to be without a wheel for an unknown time period though, especially since winter is coming.

 

[IggyBBR]

Don't think the bike brand matters, since these were wheels I upgraded too, maybe about 3-4 months after purchasing the bike and realizing the original set it had unsealed bearings. Not sure why any eMTB (or bike, costing a few grand) would come with unsealed bearing wheels. The motor is a Bosch CX. I sent it out yesterday, I'll find out in a week. I could have save myself some time, if I had a spoke tension tool (or a local shop with one) to measure to send them the results.

 

[IggyBBR]

Update:

Received my wheel back today, after a few weeks at two different shops (the seller/shipper & a local shop who was building the wheel).

Short sidebar story, I purchased the Wheel set from Performance Bicycles, over the past year they went out of business and got brought out by A-Main Hobbies. Who's is currently still selling bike products under the "Performance Bikes" name and old stock.

@Mtl_Biker It's possible the tightness was the cause of the stress cracks, but I do suspect it was also cause by the motor and my pedaling force. I recently had a derailleur adjustment, using the original rear wheel temporary, and discovered that derailleur might be bent. I ordered a new one, and have it rechecked with the rebuilt wheel, with hanger alignment tool. With everything being just happening on the drive-side means I have to pay attention to that area of the bike. I suspect this might apply to anyone else with an eMTB or eBike.