Framebuilders - Repair a broken fork?

Hi, I have a track cromo fork. The steerer tube has come apart from the crown lug. Both the lug and tube are free of cracks. Wondering if would be possible to re-braze tube in crown. I have up loaded a pic. Any advice would be very much appreciated. Cheers

Yes, it can be cleaned and rebrazed and NO, I wouldn't do it. That fork was VERY poorly brazed when it was initially built and that makes the rest of it suspect as well. Time for a new fork.
Just feel lucky that it didn't cause any injury when it came apart.....or at least I hope it didn't.

Thanks for your reply! The fork is off a professional TRACK frame(NJS) I assume it should be of high quality build. The previous owner used the bike on the road for trick etc. Which they are not made to do thus the brake. He wasn't hurt. One last question, for a strongest join, would you recommend brass or silver brazing? Thanks again!

Silver may be best as it reduces the risk of unbrazing the existing joinery. It may be impractical though, as once the rust is removed the clearances may be excessive for silver.

As the above poster mentions, however, the entire fork is suspect, based upon the very poor brazing exhibited by the failure.

I'm going to bookmark this thread for whenever the SS/FG kids talk about how perfect NJS frames are.

Oh, and FWIW, don't let anyone try to rebraze it "freehand". You'd be amazed how much misalignment can be introduced at this joint. I did something similar and ended up with more than a centimeter of misalignment at the dropouts -- and this is not a misalignment that can be coldset. Make sure that a jig is used.

Thanks....guess they aren't all perfect, but they do look nice. Def will be using a jig....cheers!

Vivalo was removed from the NJS standard because of bum forks in late 07.

Fwiw, I've built two lugged mtb forks (same type of construction as yours) they are silver brazed and one has 4 yrs and 20k miles and the other is newer, only two years old with about 5k on it. Both are regularly ridden on rocky singletrack and the one on my bike (the older fork) is jumped quite often....they are both still going strong.
I'm saying all that to make the point that a properly brazed fork, regardless of how many tricks are done on it, won't fail the way yours did. Blades will bend, dropouts break, the crown will crack, etc- but you won't pull the steerer out of the crown.

True, vivalo was pulled from the njs, the accident in question involved a rider running into a fallen rider resulting in forks breaking. The ban was considered unreasonable by many. Yes, live wire, your bike forks sound like they are sturdy, I have ridden mtb bikes with rigid forks of 4 foot drops with little worries, but they were for mtb and not built specifically for racing around a smooth track. That said, I was preety surpirised at how smoothly the forks came apart. Anyways, thanks for the help, will have a go at silver blazing em together...using a jig of course.

that looks like chrome plating, which should be removed for safety. Brazing a fork crown properly requires a lot of heat for a long time.


The failed joint is clear evidence of malpractice. It was built by someone who doesn't know what they are doing. Whoever let them build it is likely allowing other novice builders to endanger other riders. There simply is no way of having such a failure on a properly brazed crown, it simply cannot happen. And furthermore, if they had gotten anywhere close to getting penetration, the failure wouldn't have happened either.

On further reflection, I see what happened. They got penetration under the headset seat and stopped there. That's why you have to pull braze material through the crown until it comes out the other side.

yes, it seems like all things point to a bad build. I will talk ti vivalo, maybe they will repair it for free......thanks for the input!