Reborn Engineering: Handlebar Risers

Just finished up the Part 1 of some handlebar risers for the motorcycle I'm building. Took longer than I thought, made some paperweights in the process (i.e. I fudged a part or two); but the end result was well worth it.

I had planned on making these out of aluminum just because there would be a lot of machining...stainless would be doable, but it would be a bear. I modeled them up in SolidWorks, ran calculations on strength, and modified the design until I felt comfortable. After all, these will be holding the one thing I have to control the bike. Here's what I ended up with.

I wanted to be able to hide all the mounting hardware; the handlebar will cover the large mounting bolt and I'll make a cap (not shown) to hide the clamping bolts. Time to order material! $150 later I had a 12' stick of aluminum and more than enough hardware.

I was pretty bad about pictures starting off, but basically I turned the profile on my South Bend at home out of 1.75" aluminum. Then it was off to the mill to make room for the handlbars and the clamping bolts. So many chips!

About 5 hours on the mill and the risers were starting to take shape.

Then it was back to the lathe to finish up. Splitting the halves wasn't easy with the giant 1 inch hole through the center...part off tools don't like interrupted cuts. But after that was done I faced off the halves to the correct dimensions and tapped the clamping bolt holes.

I had a piece of 1" tubing that I'll use to make the bars, so I tested the clamping strength on that. They showed no signs of budging and were looking good.

For the large 1/2"-20 mounting bolt it required a 13/16" counterbore. The largest end mill I could fit in the tailstock was a 9/16". So I started there and bored out to the right size.