well heres what im gonna try first, a half dead D952 theres 3/8th carriage bolts put in form the inside, with big washers and the nuts are countersunk out of the way, and i jammed a pumped up 19" tube in there and am still using the tubliss too, but i could prolly run flat cause of all the centrifugal force tho, just start from 3rd
i still have almost 2 inches room in between the bolts and swingarm, so im pretty sure there wont be any race clearancing...
the thing prolly weighs 40 pounds now tho
it took 4 hours to do...
ride report coming tomorrow, im hoping it helps on the roots too, ill be trying to get up this, theres snow there now tho

but im still going anyways
got screws on the way for the front, and the side rear knobs too
the 450 will have less power and will be harder to start, and will be heavier, but to make up for it it will require more maintenance.
4stroke=dead fish