The big problem here is trying to find a RH crank arm WITHOUT at least a spider fixed to it. I could just order spare crank arms from Bafang supplier and replace if one gets bent or broken...but I'd rather have an arm that can take a little bumping without bending like that. Trail biking, every now and then your gonna 1. fall 2. clip something. Another idea is to get a good quality alloy T6061 or better crank set and cut the spider off of the right side, or looking at the assembly close, I don't think a spider would even interfere with anything. I thing the Bafang engineers really didn't put thought into the crank arm design as they figured usage mostly for commuting or road/path riding, not crazy Americans riding single tracks through the woods.