I was just attempting to use a lathe at work to cut the crown-race-seat on a fork that I’m building. I had it all set up, and then accidentally bumped the cross-slide wheel and drove the carbide cutter into the steerer tube. I made a small gouge in the tube, similar to what you’d see when a ball bearing slips out of the headset and wears a track in the fork.
Is this fixable? Wondering if I can fill in the groove with some weld, grind and file it smooth, and be good to go?
I’ll post a photo tomorrow - I’m at home and the fork is at work.
Oh, bad spot to have a weakened fork. You look at fork recalls in the industry and it seems like the smallest of imperfections in a fork can be disastrous. A cable rubbing the side of a carbon steerer causes a stress concentration and the fork fails. Adding some weld might introduce additional issues too. Some others that have actually built a fork might have a different view, but the structural engineer in me is saying don’t use it.
Jim
I would cut that fork up and check how well you brazed it.
The far side looks cold, but it’s hard to tell.
The gouge is a bummer, but V2 is almost always better than the first try
I have to agree with the sentiments above. I would chalk this up to the learning curve and start fresh. Cutting it up to see how well it was brazed would also be worthwhile. It may give you a level of confidence that you know what your putting together will last. The first fork I made I really struggled to get the brass to flow from one side of the crown to the other and ended up feeding brass in from the opposite side. In the end, I decided that I wasn’t willing to chance that error and have since used that fork for paint testing for the last 10 years.
Ah rats. I put this together with silver, think there’s a good chance of me being able to melt out the steerer and replace it with a new one? I guess it’s worth a try, otherwise the whole thing is scrap…$$$ down the tube.
You’ll need a bunch more heat to unbraxe it than when you initally dd it. If you were going to do that you need to cut it off and section it so you can remove bits at a time.
As a side note you’d be surprised how little braze you need in that socket. I do always do a full wet out all round with silver but I’ve seen plenty of production forks, and some from some very high fancied brands, with not much braze in that socket when doing repairs. These forks had been ridden for years like that as well.
Caveat emptor. A friend of mine bought a Bob Jackson lugged road bike a few years back and there was so little braze in the crown socket that the steerer fell off! Luckily he wasn’t hurt and they replaced everything, but it was very scary nonetheless.
