Shoring Up the Bars

Story by Adam Bowser

Photos by Nick Altland

We were fortunate enough to have Adam Bowser, the highly motivated owner of Moto PGH, assisting us in the CRM garage recently. In this issue, the prolific builder of over 500 custom cafe racers shares his practical insights into keeping classic Japanese motorcycle roadworthy - editor

The handlebars on the 1972 CB450 feel wobbly when you grab onto them and that’s a common problem on older Hondas. The problem is with the two rubber bush- a few decades, they shrink from just drying up from being so old and they can make the bar risers feel wobbly.

There’s a couple of ways to fix this problem with some guys opting to just replace the riser hardware with bigger-diameter riser inserts that eliminate the need for rubber bushings at all. This works, but without the rubber pieces you get a lot more vibration through the bars, especially on one of these bigger 450cc or 500cc twins. You don’t notice as much running solid- mounted handlebars on a CB750 or one of the smaller displacement fours.

You can buy a new pair of rubber bushings, but they’re hard to find and can cost a lot if you do find NOS bushings.

A cheap shortcut I do on some of my classic Hondas is to just wrap the old bushings up in electrical tape. This makes them bigger and helps the bushings to fill up the space inside the holes in the top triple clamps. It seems like it wouldn’t work, but I’ve done this on some of my own bikes and ridden hundreds and hundreds of miles with no problems.

Just unbolt the risers from under the top triple clamp and the bars will lift out. The bushings are just sitting in the holes so be careful or they’ll drop down and roll across the floor. Use typical black electrical tape and wrap them a couple of times around, stopping to check and make sure you haven’t wrapped them too thick so they can’t fit back into the holes.

Shove the wrapped bushings back into the triple clamp and slowly slide the threaded riser bolts back through the bushings, being careful not to knock them back through. When you tighten them back up, do a few turns on each instead of completely tightening one all the way and then the other.

Once the handlebars are back in place, when you shove on them, you’ll notice they aren’t moving around a lot anymore. There will still be a little bit of play in the bars, but that’s OK. If there’s still a lot of play you’ll want to replace the bushings because they may be cracked or worn out. CR