OMS Ironhead Thumper : 01

So I decided to throw my hat in to the ring for another Ozark Mountain Scramble. I deal in American bikes and parts on a daily basis so I thought it would be a good idea to utilize my knowledge or interchangeability and a part stash from other projects that I have done.

We will be building a 1975 Harley Davidson Sportster. You say foul! Harleys cost too much and are too large for the displacement rule! As you may know the Ironhead Sportster is at the bottom of the food chain as far as American V-twins are concerned. They can be acquired for a song running and if you do a little wheeling and dealing you can get a basket case bike on the cheap.

Have you ever heard the term for a Sportster as “Half A Harley”? Well that is what we plan on doing to get the bike to fit the 750cc displacement rule. The 1975 Ironhead Sportster motor is a unitized construction V-Twin with cast Iron cylinders and cast Iron heads hence the term “Ironhead”. We thought that we would cut down on the bore by sleeving the cylinders and new pistons. This would make it a 750cc V-twin. The more I thought about it nobody would believe me that I really did the work as there would not be a good way to check the motor to make sure I was not telling a tall tale. So, the plan is to take this V-Twin and turn it into a Thumper Single! I have a few ideas on how to go about this. We will be posting pics as the progress unfolds over the next few months.

Tim