Steerer Lenghth Question

[Heavy]

I have a bike with a 125mm head tube which has 1" threaded rigid forks.

I'd like to use these forks on a bike with a 130mm head tube.

Before I start stripping things down and measuring stuff, is this likely to be possible?

Thanks.

 

[RetroDavy]

It will depend on the headset. If you can find one that has a stack height of 5mm less than the one on the frame with the 125mm head tube all should be well
"Sheldon Brown's Bicycle Glossary St - Sz" https://www.sheldonbrown.com/gloss_st-z.html

 

[RetroDavy]

Although (as I found to my cost some years ago) not all 1" headsets are the same. Any replacement headset will need a crown race diameter that matches your forks: generally 26.4mm (ISO) or 27mm (JIS). Well worth checking!
https://sheldonbrown.com/cribsheet-headsets.html

 

[Heavy]

Thanks Davy that gives me a starting point.

Currently, the 125 has an XT headset as pictured.

 

[FluffyChicken]

Nah, give up given you're missing the lockring which is recommended to have.
The XT headsets are quite low stack (and decent).

M735 headset total stack is 32.7, minus lockring is no idea 30-31mm

Lower stack is 11.5mm so doubt you can save 5mm finding a different bottom half.

You could look to finding a different top part and a short locknut but that usually reduces threads.

Anyway you have some info there... 25mm threaded headsets...?

New forks would be easier and not a compromise.

 

[Rod_Saetan]

Lowest stack 1” threaded headset is a Tange Passage at 30.3 mm.


AFAIK.

 

[Heavy]

Thanks folks - that's all set me away with some good info.

The reason I was keen to use those forks is that they both frames are Paul Donohue, but the one with forks is cracked, so it would have made sense do do the old switcheroo.

Anyway, I'll look into it further and see how things pan out. Thanks again

 

[Heavy]

Here's a quick preview - paintwork is pretty much prefect.

 

[RetroDavy]

Another thought, if you're thinking of replacing suspension with rigid, is considering the axle to crown length as big differences will affect the geometry and handling. Not something I've done so I can't comment on what it means in practice.

Nice photo - the Tyne?