Rock Shox cut steerer tube

[Koupe]

@stesnape: That's the problem though. You have conflicting stresses working on each end of a tube, with a weld (weak spot) right in the middle. How many of the tubes on your Ritchey frame are formed from 2 pieces welded end-to-end? When frame-builders repair tube damage, why do they change the whole tube when chopping out a small section and welding another in would be much quicker and easier?
A lot depends on the kind of riding you're doing (it might never fail with gentle trail use), but regardless of how skilled the welder is, it will never be as strong as it should, and I'd never want to risk it.

 

[stesnape]

Yeah, bike shop owner said only option was new forks, time served welder and sheet metal worker said easy. Thanks dad!

 

[dyna-ti]

Inside the headtube i think you will find the steerer flexes back and forth.
I'd prefer a straight uninterrupted tube for that duty. Having a break in there will stiffen it and if its going to crack then it will be at this point it goes :?

The ONLY time i would think of extending a steerer is with a quill type extension. All the steerer has to protrude from the top of the headset before an extender is fitted. Below it is not a good place
You also cannot see the weld if its in the headtube,so have no warning of impending disaster :?

ANYTHING happens to the steering in that you lose all control will result in pain and injury. At speed offroad or in rush hour traffic that could very easily prove to come with life changing injuries or death.

Offroad :? Fork slamming about :? Weld of unknown quality* :?

Madness


* Not a slur on the welder but did he xray it? and full dressing and preparation of the tubing to be joined ?, Completely aware of the stresses on such a piece of tubing ? where these stresses occur ? If no then its a weld that cant be verified.

 

[WD Pro]

OK, my first choice, if original components are readily available and cheap would be replacement, however ...

I can't comment on how the OP's father has done the fix but consider the below for a relatively easy fix (for any workplace with basic engineering facilities) :

• Cut steerer squarely to approx half the length that's required.
• Ream inside of steerer to known diameter.
• Cross drill steerer (two holes) about 20mm from cut - 5mm dia hole.
• Turn through 90° and cross drill steerer (so it now has four holes) about 40mm from cut.
• Put weld prep on end of steerer.

• Turn a new piece of steerer.
• Piece should be stepped / two diameters.
• Small diameter to be press fit into fork steerer.
• Small length to be 10mm + longer than holes in fork steerer.
• Large diameter to be correct steerer diameter.
• Large length to suit required steerer length.
• Put weld prep on joint between two diameters.

• Press parts together.

• Weld around joint (tig).
• Plug weld the four holes.

• Reface crown race seat.

That fix, done with the correct materials and process isn't going anywhere ... ;-)

If you still have concerns, run it with a ring o star style clamp assembly - belt n braces etc

The only real negative that the above fix adds to the equation is a bit of extra weight ...

Considering this is a website centred around old bikes / components and restoring them, it sometimes surprises me how quickly some things get condemned ... :?

WD

 

[unit3]

What WD posted is correct but a little over the top for a steerer tube, but is the way to do it for ultimate streangth.

The part put under most stress and that will flex while riding is at the fork stanchion/crown where the stanchions are press fitted or clamped.

I would trust a time served welder/fabber.

 

[Retro Spud]

That WD posted is correct but a little over the top for a steerer tube, but is the way to do it for ultimate streangth.

The part put under most stress and that will flex while riding is at the fork stanchion/crown where the stanchions are press fitted or clamped.

I would trust a time served welder/fabber.

+1

Many many moons ago I had a Quadra 21r steerer welded up along the same lines as detailed by Mr WD and that fork was seriously used and abused, aside from being a tad heavier it stood the test of time, but then 50% of people will say I was just lucky (perhaps I was )

I've since bought a well worn / clapped out RS Judy for spares and the steerer on that had also been extended, so neat was the job that I never clocked it at first,

I think its far more common than you'd give it credit for.

Spud©™