I dont know much about headsets. I typically leave them alone. But I now have an issue on the new frame I bought recently.


Problem is the headset has movement, particularly the lower bearing. Even when its adjusted tight it still moves. So when riding and the brakes are applied I get a jerky stuttering effect. Its a Stronglight steel headset. I tried a different fork race and the movement was less but I think its the lower cup thats just too big. Or is it that I am using a caged bearing? Will loose bearings take up the slack?

Did you check that the cage is oriented correctly and not upside down in there?

Other than that, I will leave it to the pros.

good looking bike!

-----

its always good to begin at the root

suggest to face head tube & mill fork crown race seat

headset does not "look" like a Stronglight model P3 or V4

looks more like something from Etablissements Gourgaud (LIGHTRACE brand)

if the lockring is marked Stronglight it may be that the set was put together from pieces

one thing encountered occasionally is a cycle whose headset has been assembled from miscellaneous bits which do not always work well together

suspect source of looseness may be fit of lower head cup in head tube and/or fit of fork crown race - this is a fit which needs to be tighter than interference; it needs to be press

if one of these fittings in not tight enough shimming may be in order

if using retainers try changing to loose ball - these will give longer life in terms of brinelling resistance


-----

Buy a new headset. They're cheap.

^ This! Sounds like the existing headset is bodged together from disparate, not-quite-matching parts, including the crown race you swapped in. Start fresh.

If the movement is only front to back and is confined to the bottom of the headset, that suggests that the head tube has become "ovalized," such that the bottom headset cup is no longer firmly held in place and is rocking forward and backward.

I had that happen on one bike, an early steel hybrid that I rode hard on rough single-track trails. A car mechanic I described the problem to recommended one of LocTite's tougher formulations. I used it - problem solved. Cheap fix. Might have been this one:

"LOCTITE 660 is a high-strength retaining compound with good gap-filling properties, ideal for repairing worn-out seats, keys, splines, bearings, or tapers without remachining."

Edit: as I recall, it takes some hours for the compound to harden. Might be best to keep the headset press in place for at least half a day or so.

Interesting. This could very well be the case. I have adjusted over and over again and it feels as if its properly adjusted and then it works loose just by me rocking the bike back and forth with the front brake activated. I have used Loctite on bottom brackets where theeads were damaged. Worked well. I will investigate further.

-----

tip -

the Gripfast seat binder you are using on the machine is Whitworth dimension


-----

How are the threads on the fork and the headset? had this issue with a Peugeot and the threads were trashed causing the headset to loosen..

​​​​​​​Yup! been there and done that. I works.

Are they caged bearings? If so, like someone above mentioned, it might be upside down. If loose bearings, maybe wrong number of them?

Can you confirm the lower cup is loose? The 660 probably won’t help if it’s snug in the head tube.

Could be the wrong sized bearings.

A replacement Stronglight headset for that vintage, if you care about keeping it original, won’t be cheap. You’re probably looking at $100 minimum, if you can find one with decent races.

Goid looking bike, by the way. I always liked the look of Libertas bikes.

Good catch. Only binder bolt I had handy.

I just want say sweet ride nice find! Of course it will bee all the sweeter with a headset fix, good luck with it! Let us know how it’s rectified

Since the OP suggests he got it as a "frame," then nothing is "original." He doesn't need a $200 NOS Stronglight headset. He should just spend $20 bucks and get a new headset, instead of trying to put 20 Band-Aids on it. Could have been purchased and installed by now.

Messed with the headset again. Went to the hardware store and matched up the bearing size to the one good caged bearings I had. I assembled the headset with the caged bearings on the bottom race and loose balls on the top race. It now functions properly. I just dont like headsets. Hope I never have to open up this can of worms again. And the bike rides oh so sweet.

-----

great to read you got it sorted


-----