Originally Posted by rickie h
well id like something bicycle worthy :P
No reason to commercially manufacture anything much bigger, unless you want to manufacture rear wheels as well.
When you start putting much-larger engines on bicycles (4-5+ HP) you run into the issue of the rear wheel bearings and spokes dying very
early deaths. You can get thicker spokes with the Worksmans and Huskys, but the bearings are still the same.
The couple bikes I've seen (online) with Lifan motorcycle engine/trans setups--one had a moped rear hub laced into a bicycle rim, and the other used a whole motorcycle rear wheel.
If you want something that will really
scream, look at some of the snowmobile engines.... They're still mostly 2-strokes, so they're pretty compact and powerful--the SMALL ones are 30-40+ HP, and they have a CVT already built-in.
Ted Wilkins - Snowmobile engines | FF Web