Jeep,
Of all the bikes I have looked at, yours is my favorite. I hope you don't mind, but I am attempting to copy your design. I received a welder for Christmas (had to drop a hint or two(and one e-mail)), and I needed a project to build. Well I love anything with an engine, and one thing led to another and here I am.
I was hesitant to post anything since I was not sure how it will turn out, but I made enough progress that I think it will look ok. I am taking photos of the whole process, and may do a log if I have time.
I have a few questions, if you don't mind. I think you mentioned some where that they were 18" tires, but were they larger than that once inflated? I am using 22" tires and cant decide what gear ratio to use. I plan to use an 208cc motor from Northern Tool or the 212cc from Harbor Freight.