strathconaman

Hi Everyone,

I have acquired a frameset where the previous owner shortened the steerer tube beyond the point of usefulness. The fork matches the frame and is pantographed, so I would like to fix it.

I have watched this:

Paul Brodie walks us through extending a steerer tube. I would like to give it a shot. My question is if TIG is the only option, or could this be silver soldered and work as well?

Andrew R Stewart 

For silver to be safely used requires a close fit, for enough surface area, to attain the needed strength level. Not what a butt joint offers unless a sleeve/plug is used, which is a common method and one that I've done quite a few times in varying tube diameters (although not yet a steerer). How deep into the steerer your stem needs to be and where is the steerer's upper edge of the butt transition are two more factors I would want to know. I have recycled a couple of fork crowns in my past and would consider replacing the entire steerer first. Andy

unterhausen

I think I would find an experienced framebuilder that's willing to TIG it for you. I have no idea who that would be. TIG has the advantage that the heat is more localized, so it's less likely to mess up the paint/chrome.

I'm with Andy on silver. I would only do it if it was the zombie apocalypse and I had to have a bike to escape with my life. Replacing the steerer seems like a better idea.

Portlandjim

Any type of brazing to do this repair is not a good idea. TIG welding the steerer does work, with some skill and care. Be advised that Reynolds 531 tubing is not recommended for welding, 4130 CrMo is fine though. Here is what I have done for this repair. The cut should be in the area where tubing is still 22.2mm (0.875") and below the threads, Avoid making the joint right where the stem wedge or cone will be. Make the cut have a 45 deg bevel on the outside, on both the fork and the new tube. There should be no chrome or paint near the joint, and clean the inside of the tubes also. I use a solid steel mandrel, 7/8" cold finished 1018 is OK. This should fit inside the fork and extension tube nicely with just a little clearance. There should be zero at the bottom of the V groove, both tubes evenly cut at 90 deg. Tack the V groove joint in about 4 places, use care to not weld the mandrel in place! If you are a good welder, the mandrel can be left inside as you carefully finish the joint. If even a tiny bit of weld sticks to the mandrel you are in big trouble, check to make sure it's free after short welds. Rather than take the chance of welding the mandrel in place, you can choose to remove the mandrel after tacking. In this case it most likely will need a reamer to clean up the inside of the steerer. I have done this repair many times, and never had any issues. It may be difficult to get anyone to do this and risk the liability however.

Kai Winters

I'd not trust it...but that's me...you do you and good luck to you too...