Fmpapierz

I have a 1 1/8" headtube with cups welded on. Is there anyway to reduce the size of the welded cups from 1 1/8" to 1"?

dabac

Are you sure? I’ve never seen that, not even as a hack repair.
The cups? AFAIK, no.
There are shims to install 1” headsets in 1 1/8” headtubes though.
If it was me, I’d try shimming 1 1/8” crown and top race onto the 1” steerer. Or grind the welds/cups out before trying to rework the cups to take another size of bearing.

CliffordK

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CliffordK

Ok, that is a most interesting bike/frame.

Welded Aluminum frame? Generally aluminum is considered too soft for bearing races.

I'm assuming it is some kind of motorized kit that you are adapting either a vintage 1" fork to, or a reproduction vintage style 1" fork to.

I'd have to see what the walls of the inside of the head tube look like, but I assume they're machined to 33.8 to 33.9mm with straight sides for at least 1/4", then some kind of a step to the inside diameter of the head tube.

Here is the Problem Solvers headset reducer. I'm not seeing it on the Problem Solvers website, so it may be discontinued.

https://www.nashbar.com/problem-solv...hd9901/p314093

And Wheels Manufacturing Headset Shims.
https://www.ebay.com/itm/NEW-Wheels-...A/283516068171

Again, I'm not finding them on the Wheels Manufacturing website.

Looking at your picture, I'm not seeing the headset cups. Do you have them? This spacer will still require the entire 1" threaded headset.

I assume the upper "cone", and lower "crown race" are also there, but hidden.

dsaul

I don't see any headset cups on that head tube.

HillRider

Without pictures I can't be sure but I expect what the OP is describing is an "integrated" headset where the bearing cups are integral with the headtube.

Wilfred Laurier

Hard to tell from the one small picture, but it looks like it is a frame designed for 1" headset and just needs bearing cups pressed in. The difference in diameter between the fork steerer tube and the frame headtube does not look big enough to accommodate bearings meant for 'integrated' headsets, but does look what I would expect to see if you put a fork through a traditional 1" frame without cups pressed in. Again, hard to tell from the one small picture so I could very well be wrong.

OP: Have you measured the inside diameter of the frame where the headset should go? A detailed photo without the fork present would also be helpful to figure out what we are looking at.

CliffordK

The loose (caged) bearings visible in the photo are almost always part of a cup and cone set (with the cups missing from the photo).

Measurements of the fork and headtube as above would help. Perhaps also a description whether the fork and frame came from a single supplier as parts of a kit, or were being assembled from parts acquired individually.

Here is a diagram of a typical threaded headset.


https://bike.bikegremlin.com/3246/na...headset-parts/

A few variations in type. For example, I prefer a cone for the top bearing "cup". Nonetheless, it should give an idea of how it all gets assembled.

Overall, the headset cups should be a tight fit, and need to be pressed in.