the headset cup isn’t perfectly round. the bearing has to be hammered in to fit, and creaks when riding. can this be fixed? this happens on the bottom one as well
by Fred-F
the headset cup isn’t perfectly round. the bearing has to be hammered in to fit, and creaks when riding. can this be fixed? this happens on the bottom one as well
by Fred-F
11 Comments
This would generally be called an ovalized bearing bore or bearing seat. If it’s not severely out of round, it may be fixed properly with specific reaming tools. This is a cutting tool that would ream the bore’s inner face to a proper tolerance and ream the lower angled portion where the bearing sits. Park Tool only makes a tool for the IS41 standard, but VAR makes tools for IS41 and IS42 Campy. These tools are very expensive and unfortunately many bike shops do not buy them due the infrequency which they are needed. If you have a really technical bike shop in your area who might have these tools, that’s the place to start.
Hammering a bearing will damage it and the frame.
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Square peg round hole springs to mind. I had a brand new frame with this issue, I spent hours with 1000 grit sand paper sanding down the inside of the head tube to increase the diameter and that worked to some degree, the bearing did fit but it still creaked after about 4-5 rides and then I’d have to reapply some grease to make the noise go away. I bought a different fame as my solution as the tools to do it are very expensive and no bike shops local to me would touch it.
New frame
Damn, that looks terrible. No chance of warranty I assume? As mentioned, you could sand or carefully Dremel it out to prevent the need for hammering it in, which is a terrible idea.
Don’t use a hammer. Use a press. And apply some Loctite 609 bearing retaining compound to the outside of the bearings to fill the gaps and silence the creaks.
Over the years, I’ve built several frames from the frame up. I find that headtubes are often not as round as they should.be, which is really a shame. I always run a reamer through the headtube to make sure the cups or bearings fit. You might need to contact a few local bike shops to find one that has the correct reaming tool.
Remove the paint in the bore first, you can use some steel wool to tickle it out.
That gap is truly appalling! It’s supposed to be at most a 0.2mm clearance (+0.05 -0.00), id personally be sending that frame back if it’s new because the general quality is shocking. (Your gap looks like 1mm in the worst area and also looks like there’s a crack? But that could be paint.)
This is quite a severe manufacturing defect and there isn’t any way to fix that. If you ream it out then you’ll still have a hole that’s too big and not concentric and the manufacturer will definitely want to know about this.
Alternatively you can bodge it with locktite but you’ll probably still have many of the same issues, you should also never use a hammer when dealing with bearings!
What’s up this?
https://drive.google.com/file/d/1qrw94HSPghLJGpcPFqQglPy4Rfoi6aWS/view?usp=drivesdk
That looks like a hairline at 12:00 in your photo?
Did you hit the frame with the hammer a couple of times?
I think you know this frame is done at this point. That creak isn’t going away without paying a professional if it even is possible to fix.
The forces on a bike under load are quite scary when you consider the potential consequences!
An actual machine shop could fix this headtube as long as it isn’t already cracked. I know I could fix it myself, but it’s machine shop level service. I don’t see how a reaming tool would solve the issue unless the bore was made smaller before reaming.