I was banging my head trying to figure out a clean way to mount my Flying horse engine onto my Schwinn Riverside. The motor mounted just fine to the bike seat tube but the bottom tube is too big and it is too low so the motor would hit the chainguard/chain wheel area. I used the small adapter plate that bolts to the engine and creates a wider set of holes. I then drilled a 1.5" hole into a block of UHMW (ultra high molecular weight) plastic. This stuff is super tough. I cut across the hole I just made which created a rounded notch so that the block could rest on the bar below. I drilled two 1/4" holes on each side of the mount so I could use 2 4" carriage bolts to mount the block to the bar. Tell me what you think.