Repair crack to head tube of aluminum cycle frame?



Dexter49

Member
Oct 10, 2014
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The head tube of my Specialized Sirrus frame has a shallow two inch crack half way down the head-tube.

Can I get it repaired by a welder or is it toast? I am still riding it for now but am getting nervous it might fail and dump me down the road.

Thank You
 

dabac

Well-Known Member
Sep 16, 2003
2,298
288
83
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Tubes like that don't develop shallow cracks. Either it's a scratch, or it's a crack through.

It's an aluminium frame, right?
There's no general agreement on whether aluminium frames are repairable or not. Some alloys need time consuming heat treatments after welding to regain the expected material properties. And not many shops would do that at a price that'd make sense.
A headtube crack often stems from the headtube not being machined out quite enough to take the the headset cups/bearings. You may want to contact a Specialized dealer and see what they say.

I've patched up a bike with a cracked headtube by using a lathe to make a steel collar that was pressed on/over the cracked end, thereby cancelling the splitting force exerted by the press-fit cup/bearing. Worked fine for me, no guarantee that it'll work for you. And you need to have a lathe.
 

531Aussie

Well-Known Member
Apr 11, 2004
12,652
303
83
You should be able to get it fixed, but the welds are usually thick and not very pretty, if that bothers you.

I had an old one repaired after stupidly putting in some headset cups that were way too tight .

However, the area on the head-tube where the old headset cups go in (old-style head-set) is noticeably thicker that the middle of the head-tube, and I gather that can make a difference when it comes to welding
 

CAMPYBOB

Well-Known Member
Sep 12, 2005
11,945
2,086
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Use the Force, young consumer-wan! See you jedi-dealer for details.

Specialized bicycles are sold exclusively through our network of Authorized Specialized Dealers.
Specialized Bicycle Components, Inc. provides each original retail purchaser of a new Specialized
bicycle or frameset a limited warranty against defect in materials and workmanship as follows:
LIFETIME
„. Frames and forks on complete bicycles and framesets for the lifetime of the original owner (subject
to exclusions under the 1 and 5 Year periods below).
Specialized bicycles are sold exclusively through our network of Authorized Specialized Dealers.
Specialized Bicycle Components, Inc. provides each original retail purchaser of a new Specialized
bicycle or frameset a limited warranty against defect in materials and workmanship as follows:
LIFETIME
„. Frames and forks on complete bicycles and framesets for the lifetime of the original owner (subject
to exclusions under the 1 and 5 Year periods below).
 

bing181

New Member
Oct 23, 2004
135
0
16
FWIW, I wouldn't be throwing a leg over any bike with a crack in the frame. This after I broke my collarbone when I came down on a smooth, straight road, for no apparent reason - and subsequently discovered a hairline crack in the head-tube of my aluminium frame.

Also, FWIW, have subsequently been told (by a frame maker) that it can't be repaired because the aluminium is too thin (see above ...), and only solution would be to replace the head tube - which the manufacturer has offered to do for a tidy sum (no guarantee in this case).