Extending Kona P2 steerer tubes.

[August Bicycles]

We have done plenty of steerer extensions, as most of them are aheadset and not threaded, we use a press fit internal cromoly sleeve at the join, it keeps the two parts of the steerer aligned and reinforced when we TIG weld everything together, we then file everything smooth.

Attached is a picture of one we did a couple of years ago with daily use since with zero issues. after the weld is dressed, its basically invisible.

This is how trophy trucks and the like repair roll cages if they have been damaged in a crash, if its good enough for a 5500lb truck that flies through 5 foot deep whoops in the desert at 120mph, its probably good enough for a bike!

 

[winjohn]

Sounds perfect. I'll email you.
Cheers
John

 

[retrobate]

I have done the same as August Bicycles and never had an issue. I took it a little further & also drilled 4mm holes every 90 degrees in the steer tube either side of the join & welded the sleeve to the steer tube at each of these holes so even if the butt joint failed there is a bit of a fail safe.

Here is a vid from Paul brodie extending steer tubes

 

[bikeworkshop]

I have done the same as August Bicycles and never had an issue. I took it a little further & also drilled 4mm holes every 90 degrees in the steer tube either side of the join & welded the sleeve to the steer tube at each of these holes so even if the butt joint failed there is a bit of a fail safe.

Here is a vid from Paul brodie extending steer tubes

I have also done the same (brazing a sleeve in rather than welding)
but i would advise customers get a suitable fork instead, because there's plenty of choice nowdays.

Of course for a vintage restoration, there will be diffetent priorities, and choice might be limited.

 

[klunkrider]

Done several. I braze them because I’ve don’t have the facility to weld. Don’t usually jig them or anything, just use a sleeve and it seems to keep them straight enough.

 

[bikeworkshop]

Done several. I braze them because I’ve don’t have the facility to weld. Don’t usually jig them or anything, just use a sleeve and it seems to keep them straight enough.

Ahead top and bottom bearings ought to be able to self-centralise, to a point - but a Threaded headset locks against the fork thread specifically, so steerer alignment would want to be very accurate.