iBob cross post: VO stem clunkin' around in there

[Erik Wright]

Good afternoon everybody,

I recently bought a VO 31.8 quill stem in order to try Salsa Cowchipper bars on my Sam Hillborne. I took it on some trails last week and felt some clunking around when I would go over rocks/bumps, and I could also feel a clunk when I hopped up curbs, hit potholes, etc. in the city. When I changed out the stem, I also regreased the headset. My first thought was that I didn't tighten the headset fully, but 1) when I hold the front brake and rock the bike, there's no perceptible clunk, and 2) I overtightened the headset to see if that would eliminate the clunk, and it did not.

I loosened the stem to exacerbate the knockin' around and took some videos. It's hard to tell, but in these two videos you can see a minor ~1mm rock back and forth as I rock the handlebars, no matter the height of the stem. When the stem is tight, I can't rock it back and forth that easily, but that subtle knockin' around is noticeable when I hop curbs, etc.

I had a Noodle/Technomic cockpit on the bike before and there was no wiggle/knock/clunk. The only difference between this cockpit setup and the Technomic setup is that I removed the canti brake hanger from the stem spacer stack because I also changed the brakes to V brakes.

Has anyone experienced this before? Found any solutions? I thought I'd dig into the collective knowledge of this group before reaching out to VO about a warranty or something.

Thank you!

Erik, Philly

[ascpgh]

With a sliding wedge (or other internal binding stem) the firm fit it from the force against the inside of the steerer where the wedge (or other bolt-driven thing) pushes against the tube wall.

If you have a lot of quill inserted in your steerer at your bar height level adjustment, you have a length of it not fixed by the binder, rattling or thumping in the steerer. The locknut of the headset proving the only limit to movement. If it’s inner collar is not snug around the stem quill by either smallness of it, largeness of the nut’s collar or inadequacy of the captive plastic bushing in the nut or a combination of the above, you can get sound or feel in the event you deflect the stem to make contact with the stem nut’s inner dimension.

A shorter insertion stem might shorten the lever arm you have that is creating this situation. If housings permit, try raising your stem closer to minimum insertion (binding device safely below threading of the steerer, not some mark on the stem) and try it out.

Andy Cheatham
Pittsburgh