These streetbike motors are heavier than the stock Rotax. The further you can mount them back in the frame the less weight you will have on the front weels allowing for a better balanced machine. On my 750 conversion I only run a +5" swinger and it is fun as hell to ride. It is not what I would call wheelie happy basically because I am not running enough paddles (only 10). My conversion is setup as a duner, and not so much a drag bike. I don't jump it, but I do dune it just like I did my stock swingarm DS I had before it.

 

Yep, with the R1, we both have duned it, it rides like a stock bike, but no jumping. Once you get the engine in you will see what we all are talking about. They are turned into primarily sand machines, or at least very well groomed trails, no rocks if you can avoid it. A rock in the exposed oil pan will be a very bad thing.

 

Blowed pony I was thinking about what I wrote and I messed up I mounted my center sprocket output shaft about 1/2 BELOW my swingarm bolt center not above it.