*HELP* Putting a thread on the steerer of some a-head P2's

I've got some a-head P2's i've no use for as my build turned into making the bike as true to original as possible - thanks to rb for this!

I'm finding it difficult to find the exact P2's i need (163mm threaded steerer, 410mm a-c) and i'm getting impatient!

If i could get a thread put on the P2's i have, after cutting the steerer to size, i'd be laughing...

I spoke to a local engineering firm who could do it for me but they need to know the size of the thread - they would also probably need to buy the right size tool, so could be expensive for me to cover this.

Does anyone know what size thread it is?
Have any of you done this before? - if so, where & how much was it please?

Cheers for your help guys

Not wishing you off, but I have to say, don't go there.

Thread

Try your LBS - I have got a local bike shop to extend the thread on a pair of forks before which cost me all of a fiver!

The stearer tube may not be strong enough to cut threads into, you may be lining yourself up for a trip to A&E

There's no strength problem with cutting threads into a plain steel steerer in most cases. Steel steerers, whether plain or threaded, tend to have the same basic dimensions at the upper end - 1 1/8" external diameter and a 1/16" wall. Some fancy lightweight threadless steerers may have thinner walls or butting, but I don't think a P2 falls into that category.

On the other hand, the die that most bike shops will have is designed for cleaning or extending threads on a steerer, where the existing thread acts as a guide. I've heard that there can be problems using one to cut a virgin thread, but it's not something I've tried.

If your engineering firm is happy to give it a try, the thread is 1 1/8" x 26tpi:

http://www.sheldonbrown.com/gloss_ha-i.html#headset

don't quote me on this but i think the internal diameter might be to small to fit a quill stem.

a few years ago i worked in a shop where the "mechanic" (and i use the term very loosely coz he was a cock!) had cut a road ahead steerer down too much so decided he would cut a thread on the steerer and convert it to a threaded set up, worked fine until the quill stem wouldn't fit, the fork got binned as it was then of no use.

moral is, check the quill stem fits first, then think about cutting the thread, and yes the above thread size is correct. the cutting dies can be as much as £80 each if not more not including the driver.

cost to cut thread, bitd a fiver was the norm for a bit extra thread on an already cut steerer but a whole thread? that takes time, could cost alot.

I currently have a pair of ahead Ritchey's being converted at Paul Hewitts in Leyland. Same wall thickness and diameter as my threaded forks, so I've gone for it.
I will let you know the results in a couple of days.

if your anyware bear cmabridge ive got the cutting tools to do this.

:roll: Typical,a couple of thread cutters for 1" and 1 1/8" came up on ebay about 2 months ago they were bike steerer specific
And as usual i was skint and couldnt afford them,
I think they went for under a tenner for the two :roll:

Your LBS will do it quite happily for you for a small charge,its not such a difficult or big job

jonnyboy666":2mkw5cno said:

don't quote me on this but i think the internal diameter might be to small to fit a quill stem.

Click to expand...

That's often true with aluminium steerers, but steel ones tend to be standard dimensions. Worth checking though.