DIY RAIL BIKE for less than $100

I have designed and built many variations of a single person railbike over the last year or so. However, each one of them is very specific to the bike frame geometry and requires significant design and manufacturing skills. I decided that I wanted to build a cheap and simple railbike, one that was made of parts anyone can buy from a local hardware store and can be easily adjusted to fit any bicycle. I also wanted it to work very well. And here it is, made from wood, screws, plastic wheels, a steel shaft cut with a hack saw, and some bolts to hold the circular plastic cutting board flanges to the plastic wheels. Add a universal fork mount from Amazon and you can build this in a few hours. The total for this entire build was $95 and I am sure you can do it even cheaper if you spent time looking for deals or going through surplus stores.