1 1/8 steerer tube thread size.

[Rampage]

Does anyone know what the thread is on a 1 1/8" steer tube please?
Ideally I need to know the major and minor diameters, but if someone knows the thread I should be able to find out.

Thanks.

 

[halaburt]

1-1/8" x 26tpi, H2 thread.

It's a pretty rare size outside of the bicycle world. Park Tool (and probably other bike-specific tool companies) sell dies in that size. Taps are much more difficult to find.

 

[Rampage]

Thanks.
Having trouble finding the major / minor diameter.

What I need to know is: I have a headset, if I file out the threads completely what will the diameter be?

 

[halaburt]

So you're trying to convert a 1-1/8" threaded headset to be threadless by hand-filing the threads out of the adjusting nut?

Several reactions:
- I hope you have a really, really good reason for doing that vs. the seemingly quick/easy/safe/cheap route of just buying a new headset.
- It will really only work on certain headsets -- as many (most?) models will have no hope of really being able to consistently pre-load the bearings in that configuration.
- Do you really mean HAND filing off the threads? That seems horribly tedious and your hope of having a nice round surface when you're done are approximately ZERO.

Sorry to be so negative. Perhaps some of the "engineers" on here might give you more encouragement.

 

[Rampage]

No, I'm not doing that.
It was just the easiest way to describe what I am to doing to convert some Trimnell forks I have.