OMS Ironhead Thumper : 04

We have been pecking away at the tasks to get this Ozark Mountain Scramble Ironhead ready for June 2014. Here in Western New York the riding season stops at the end of October so shop time is not interrupted by the desire to ride in sub-freezing temps until April.

The Rear spring struts were not doing it for me for the overall look of this bike. The rear sat too low and the front is too high. I found a pair of stock 13-3/8” long XL883 rear shocks in my stash that I removed from my wife’s new Sporty back in 1997. These brand new shocks have been in a box in my attic for the last 16 years. I figured this project was the perfect candidate to use these forgotten gems. So, off with the struts and on with the shocks. I like the look better than the struts on this bike but they are really soft and with my fat ass on the bike the springs compress farther than I would like. I guess we will be adding pre-load spacers to the springs to carry the extra load and keep the sag to a manageable level. We will post more on that procedure in the future.

The Ironhead motor will be losing half of its displacement when I remove the rear cylinder so we needed to give the motor a little help in the final gearing department. We installed a smaller countershaft sprocket for some extra mechanical leverage. We went from and 23/49 combination to a 19/49 combination. I pulled a few links form the existing chain so everything fits correctly. I hope this is enough to let this bike get out of its own way on the twisty mountain roads of Arkansas.

We decided to use the horseshoe style oil tank that came in the box of parts with the bike to keep costs down and mounting of the battery simple. The only problem is the original tank mounting system is flawed and parts are missing. I rigged the tank to mount from the original regulator/battery box iso mounts and reworked the original oil tank frame mount on the right side of the bike to hold that side and the third mount will have a custom bracket that ties the oil tank to the inner primary. I am hoping the iso mounts and the 4 point mounting configuration will be enough to hold the weight of the battery and 3 quarts of oil. This is all for now stay tuned for the next update for the rear tail section and foot controls.

Tim