Werkin

I've read short comments of success with Loctite 660 on securing loose headset lower cups. I would like to hear a few more details from those who have used it. Was special preparation required? Anyone removed a cup after bonding with the product?

reptilezs

is you head tube ovalized? how big are the gaps you are trying to "fill"?

operator

+1

Characterize how loose the fit is please, completely loose?, mild press fit by hand? with press? . And use a new cup when doing so we know it's not the cups fault either.

Werkin

The bottom of the head tube is 30mm wide and 29.8mm deep, clean bare metal. The cup is 30mm OD all around the neck, but it fits easily with just a slight push no twist. I don't have another headset to compare with.

operator

Test with a new cup before proceeding with loctite style repair. Are you measuring at different points on the headtube itself?

What type of headset was that frame designed for? 1" ISO? JIS? Other? What is the headset?

Werkin

Want to send me a new cup to try?

Yes, I'm measuring at multiple points.

It's one inch threaded, the frame is a US made Schwinn, Tange Falcon FL-500 headset.

The headset was becoming loose after each ride and when I pulled it apart the upper bearing cage was missing a ball, but no scoring on either race. I assume the loose feeling was the cup rocking.

DRietz

When I proposed this question, I was told not to use 660 reaming compound unless I wanted a heck of a time getting the cups out...

DannoXYZ 

Is the cup lower loose? Can you install and pull it out by hand? There is typically a 0.1mm interference-fit.

If the headset has no play before the ride and gets loose during, it's not necessarily the lower-cup that's loose. If the locknut isn't tightly pinching the upper adjustable cup, it can come loose during the ride. That could be the cause of looseness as well.

Werkin

My LBS vintage specialist installed a yellow metal shim (could have been brass or copper) from shim stock.