Otero,
Thanks for the offer. I ended up swapping rear axles with a wheel I had laying around (a solid 10mm). I ended up putting two solid days of work into '2High' and its now ready for its maiden voyage under engine power. I ran out of daylight today & will wait till either tomorrow or the next day to give it a whirl.
Here is a rough pic of the bike setup. Its got 3 chains, 3 rear derailleurs, 6 chainrings, BMX 8" rise handlebars and a Tanaka 47cc engine (not the 47R, but I do have one currently on 'The Beast'). Its currently geared for 27-29 mph under engine power which is plenty for this contraption. Under pedal power its only good for 10 mph at 100 rpm's...(I wont be pedaling much). I didn't drill any holes in the bicycle frame (its not my thing). Since the strongest tube on '2High' is the bottom bike's seat tube (I have a long ceiling fan drop pipe down my seat tube which holds the top bike in place), I attached a piece of long 1/4" angle aluminum 1st to the 2 water bottle holes, then I clamped the top section around the seat tube after grinding a slot in the angle aluminum, and at the bottom, I used a Heavy Duty clamp. This angle aluminum holds 2 of the mounting bolts for the pocket bike transmission. The other two bolts brace the transmission to the down tube (same angle aluminum bolted, then H/D clamped. The engine is solid as a rock in there.
I'll post more pics when I can get 2High out in the daylight.
Cheers,
-Low-