Cycling UK Forum

I have a Bianchi aluminum road frame. It must be over 10 years old.

There is a crack at the top and the bottom of the head tube. See photos:




The bike is not ridden very much but the cracks seems to be getting worse - so it is more likely the frame rather than the paint cracking. The headset was put in by the supplier and maybe it is too tight or hit in it too hard?

My problem is:

Is the bike safe to ride? Might the frame break suddenly or just get slowly worse?

and

Is it repairable, given it is aluminium. [The rest of the frame is in perfect condition.]

Many thanks

I wouldn't ride it. If it fails then you could be face down on the road.

Unfortunately it's not repairable. The heat from welding the crack will affect the structural properties of the aluminium. To make it strong enough again you would need to heat treat the entire frame. If the crack was in a non-critical location you could chance it but not on the head tube.

It looks like it's in lovely condition, except the crack, so I wish I could give you better news

Well, to be sure, you just need to poke a sharp knike into the crack and chip a little paint away. If it's the tubing, it's a gonna, sorry.

You could get the frame welded and then all ( or front end ) wrapped in carbon fiber.

Don't ask me what that would cost.

Gosh - if that's the matal and not just the paint (and it looks like the metal), I wouldn't ride that. Better safe than sorry. Stay alive, Beds Biker !!!

No doubt this thread will now expand with discussion about the possible causes, but there have been threads about frame materials before and those of us who prefer steel will probably feel vindicated by this.

As an aside, one of our section has had a carbon front fork fail at the crown. Luckily she noticed a problem, thinking at first that the headset was loose. Heavy braking on the descent of Fleet Moss could very likely have killed her. You hear terrible stories about failure of carbon.

Strip the frame and bin it. In fact, saw it in half first so no-one else finds it and builds it up.

As for speculation as to the cause - possibly it wasn't reamed properly at the factory and the headset cups split it. Or it was just underspecified in terms of tubing thickness.

FWIW, in the best-known fatigue test, steel came out worst for longevity!

http://www.sheldonbrown.com/rinard/EFBe ... e_test.htm

If you bought it new what is the guarantee life on the frame?

Aluminium - steel - carbon - titanium - bla bla bla

forget the bitching.

do as suggested above - ditch the frame but keep the parts. Plenty of frames around. If I had the money I would buy the first ten of e-bay right now. Not that I need any of them.

nd those of us who prefer steel will probably feel vindicated by this.

PS JohnW I have had a steel frame crack 3 places. Got it tig welded.

Looks to me as though someone wedged those cups in good and proper. They are supposed to be a press fit, but I reckon those ones took considerable force, and the cups were oversize for the head tube. It's not rideable with cracks that size.

If you had it from new, you've never front-ended it, have you?

Strip it,bin it after first following Rogerzilla's advice.
If its any consolation I had a 18year old 531 frame fail on the head tube a couple of years back so its not just an alloy frame problem,in fact looking at it I'd have to agree with Stoobs analogy of it.
The bottom race fracture could be down to stress but the top one doesn't have the same stress forces,which leads me to the think installation could be the culprit.

Thank for all the advice. I will reluctantly have to throw out the frame as everyone suggests. For info I have taken out the headset, which came out relatively easily, see pic:


The crack goes right through the tube wall and I can feel it for about an inch up inside. There is some sort of internal indent/ridge in the tube which you can see in the photo - I assume it is a moulding/casting ridge rather than a separate tubing insert because I think the crack goes beyond it.

The most likely cause is, as someone said, that the headset was knocked in with too much force - which was either Bianchi or the supplier in Bedford - no longer in business I think. I have had the frame since new (at least 10 years) and it has had no crashes or falls; and the rest of the frame is perfect. It is probably out of guarantee - I will check if I can; but I won't get another Bianchi.

It has done some time trialling but should be strong enough for that. It must be one of the earlier aluminium mass produced frames (though it says hand-built). If I get another aluminium (I don't won't to spend more money for carbon) I hope it will be more reliable, or I might go back to steel. My touring bike is Mercian and that has been faultless and has done 15k or more miles.

Many thanks

It looks like the frame wasn't reamed to size before fitting the headset. The paint wouldn't be there if it had been.

Aren't shimano JIS standard and the Bianchi frame ISO, I got a chinese ti fork last year and the crown race would not fit as the crown was JIS standard of 27.1mm instead of 26.4mm ISO size the headset needed.

"Facing is often the main objective as the average head tube inside diameter is usually unaffected, but a reamer may still be used to clean out paint overspray or to convert a 28.8 mm JIS head tube into a 30.0 mm ISO"

http://en.wikipedia.org/wiki/Headset_%28bicycle_part%29

http://www.parktool.com/repair/readhowto.asp?id=109

Don't bin the frame.

Flog it on ebay, making if perfectly clear what's wrong with it.

Somebody will buy it and even if you get a tenner, that's better than the bin men selling it for scrap money...sorry I meant recycling it.

If somebody has the means it could be brazed again to use on a turbo trainer.

I do think Rogerzilla's advice is the morally preferable one. Sorry about your wonderful bike, by the way.
Willem