I built my motorized bicycle on a Huffy Cranbrook frame using Kings 66cc kit and am now just about done with the break-in . I had the 2 liter tank on it at first, but
wanted a bigger tank so I used a Honda commercial motor 1.3 gal. tank
mounted on a home made rear rack. I've also added turn/brake/head and rear lights/ 6v. batt. charged by motor, Schwinn type speedo and a tachometer.
This summer I put 2500 plus miles on a eZip Trailz electric bike from Curries Tech. and after being caught in 4 rain showers, wanted some protection from wind and rain. I can't afford a pre-made windshield so I made my own from $24.00 of plexiglass and recycled metal scraps. It works great and doesn't seem to slow the bike much at all. I can hit 30mph, but the setup seems to prefer 25mph for smoothness and comfort.
The Cranbrook frame is OK and I get a lot of good comments on the looks, but if I build another one in the future I'll find a bigger bike to build on.
For now I'm enjoying the ride.