Extending Kona P2 steerer tubes.

[winjohn]

I'm having a hard time finding a P2 fork with a long enough steerer tube for my needs. I am looking for a triple butted, threadless, inch and an eighth with canti bosses and they seem to be like hen's teeth.

I was wondering if anyone had any experience of welding a longer tube to these. I would have thought that any frame builder would find this a relatively straightforward job.

Any thoughts?

 

[bikeworkshop]

I've extended steerers, it's not ideal.

How long do you need the steerer? There's a nice 190mm pair of later susp corrected triple butted ones in the shop, good condition

 

[winjohn]

Unfortunately that's my problem...I need at least 240mm.

 

[FZRIP]

I assume you’ve considered and dismissed the use of threaded forks with a quill to threadless adapter?

 

[winjohn]

I haven't considered that. Would that work?

 

[W7Ford]

Should be fine as long as the weld penetrates enough, a local engineering place will do it and turn it down in the lathe I'm sure. I've added a bit to a steel steerer in the past, and just used a grinder to get it flush. the part I added was between the lower and upper stem bolts so I didnt need to worry about getting it 100% smooth.

 

[FZRIP]

I don’t see why it wouldn’t.
Threaded forks, threaded headset, fit quill adapter.
Not sure how pretty it would be…

 

[bikeworkshop]

Really though, you either need an ahead fork with 230mm (ditch the spacers) or a stem with a slimmer steerer clamp, pull it down to 220.

I think an unseen weld in the steerer is undesirable, and a threaded setup inappropriate - surely it would be preferable to use a new straight fork or wait for the perfect p2 to turn up?

 

[winjohn]

Really though, you either need an ahead fork with 230mm (ditch the spacers) or a stem with a slimmer steerer clamp, pull it down to 220.

I think an unseen weld in the steerer is undesirable, and a threaded setup inappropriate - surely it would be preferable to use a new straight fork or wait for the perfect p2 to turn up?

You're right, I could go down to 220 as a minimum. I like the look of the Synchros but it does have a big fat clamp and I have a hope stem that would work fine.
If a 220 fork came up for sale then I would grab it but I have yet to see anything bigger than 210 and I've only ever seen one of those.
I'm interested as to why you feel that a professionally done unseen weld would be undesirable though.

 

[bikeworkshop]

Out of sight, out of mind.
Not always good.

You can't be sure of the material properties across the weld, you are introducing a stress riser, and you might get unpleasant corrosion at that point.

Its probably fine, for quite a long time - but why would you introduce that if you didn't need to?

You can put a new steerer in a brazed fork, by replacing the whole thing.
Additionally brazing temperatures have a lot less effect (if controlled properly) on the material's properties.