Originally Posted by 3speedslow

I tried it, unknowingly, when I put together a dirt rider from part sets I had on hand. The chainring side was 165 and the other was a 170. Both looked identical as they were from the same manuf- Sakae.

I got 1 lap( 7 miles ) around around Salem Lake when the knees started to tell me something was not right. Started moving the seat,raising the post, just nothing would make it right. Turned around and went home. 2 weeks later I decided to go forward on another project and decided to rob the dirt rider's crank. Looked at them as I cleaned them up and realized the difference.

Knees are better and I'm left with 2 orphan crank arms.