Crack in head tube ,your views Please

i have a very deep cupped syncros steel a headset i'd sell. cups are about 25mm deep so should get past the crack.

^^^^^ don't wish to scupper your potentional sale but why should a deeper headset be a good thing? surely it will put force higher up the head tube thus encouraging the crack to continue? (maybe not if a hole is drilled at the very end of the crack).

frame clearly not interesting enough to warrant a major effort. If it has sentimental value, hang it on the wall. Otherwise, send it to the tip.

02gf74":34e1aytv said:

^^^^^ don't wish to scupper your potentional sale but why should a deeper headset be a good thing? surely it will put force higher up the head tube thus encouraging the crack to continue? (maybe not if a hole is drilled at the very end of the crack).

Click to expand...

thought it would disperse the force through a bigger area.

Chris King Steelset

If it was mine I'd wall-art it I'm afraid

Even if you got it welded it would always play on your mind. Is it worth more than your teeth (or maybe worse than that) to ride something that with a bit of searching you can get again?

buy a Zaskar instead.

.... so in summary

1. leave it as is. chances are crack will continue to develop but IMO (and I may be wrong), there will not be a catastophic failure of the head tube. Worst case scenario is that the lower cup gets loose, starts to spin thus wearing the head tube resulting in a floppy lower race, and that isn't going to happen overnight

2. drill hole and fit the taller cup, the hole should prevent the crack propagating and hopefully the tube exerts strong enough grip to hold the cup in place. unless you have drill press where you can clamp the frame, a 1 mm hole will be hard to drill without breaking the drill bit - you best bet is to either go for a larger drill 2 or 3 mm or use a small electric PCB drill

3. as above but use lumiweld/technoweld (an aluminium solder) .... but i've not had luck with this stuff so i don't think it will hold

4.. repair the tube by welding it - someone ^^^^^ already offered to do that so it would cost you return postage plus a monetary gift for the welder. NB if you are local, I could have a go with my AC TIG but not really used it much so I'm probably as useful as Mike Tyson on mastermind

5. have the head tube replaced(most expensive option)

It is a 96-ish Marin RR.

Nice bike in its day, but you could pick a complete one up for 60/70 beer tokens if you have patience.

...or upgrade to a better frame for similar money.

Might even find a nice 853.

All sorted now :

Nasty little Y-shaped crack:

Marked up:

Drilled, relieved and chamfered:
Welded inside: [img]http://i139....heelchairs/Storage Folder/Marin Repair/]here.

All the best,