The pit bike/ fiddy craze is goin wild here in louisville, ky. I did the fiddy thing for a while, went on street rides where we stayed on the back wheel. but I'm 6'2 230lbs. And I'm hooked on trails so I decided to throw together a trail capable pit bike. heres what I got- xr70 frame with xr80 forks and swing arm. the swingarm wasn't hard to fit if you have a welder and an angle grinder. You have to cut the mid-section of the swing arm mount bar to fit around the 70 frame. and you have to weld the shock mount further down the frame from the factory shock mount. here's the frame, notice the factory shock mount is still there but not used. Here's the roller sittin next to a friends ct70 and here she is with her new lifan motor from ebay shipped to my door with everything needed for ~ $300, I got the semi-auto, great for climbin hills and trail riding and on the simple carrier I made for my jeep I had the motor installed and running within 2 hours of the fedex guy dropping it off, install is very easy and straight-forward. The wheel base is about 50.5" I'd bought a 120 link chain for it and cut about 8 links off the bike rides great, suspension does what it's supposed to. It does not sink or sag much when I sit on it, maybe an inch or so. The lifan motor has plenty of power, pulls me up hills real good a lot of times 2nd gear does it.