Cannondale content-is this bike still usable?

[utahdog2003]

Cracked.

I wouldn't ride that thing in a million years. :shock:

Sorry!

 

[MikeD]

If anyone knows of a reputable alu welder in the south-west, I could be half-tempted to get my Mountain Cycle Moho sorted out. Although most of me thinks that if it's cracked where it has, it's probably ready to crack in all sorts of other places too ;-)

 

[Anthony]

It seems as though Kaiser's dye test is absolutely the best strategy, and riding it to find out if it gets worse is the worst strategy.

OK if no, then fine, but if yes you'll destroy the frame, which is quite a big downside. Whereas, as things stand, I'd have thought a weld could repair it pretty well and enable you to ride it for years without concern.

 

[Chris]

Deffo get it welded,

it'll be sound

Chris.

 

[haggis]

def get the dye penetrant on it Gaz. If it is a crack then its probably came through riding hence the riding as the stay is in compression argument is gone IMO. I'd be listening to elite if i was you.

 

[sq225917]

Get it welded, that's shagged. Technical term. it was just a mark it wouldn't follow the 3d shape of the tube.

 

[Wold Ranger]

Dale

They all broke there, its scrap mate unless you get it welded, A face plant at speed into a rock? Not funny! Stay safe!

 

[elite504]

:shock: :shock:
strong words, you do have the air of one who knows what he is talking about- do you build frames elite?

Have done, but no. I design aeroplanes and parts for aeroplanes.

Yes, you could get it welded, but that would anneal what is a solution heat treated frame. It needs to be heat treated again after welding (so up goes your paintwork), and it needs to be supported in heat treatment or the stays stress releve and bow.
You can leave it to naturally age harden, and it will be ok in 150 years or so.
In the early-mid 1990s when ally frames were still pretty high-zoot, as shop I worked in got T J Quick in south london to tack up some botched 'dales and in his words "it'll break again". And they all did (no heat treatment). And as discussed on a klein thread in ebay watch just recently, the same was going on with backdoor kleins out of fusion that were being split bu USE shims that were too short. Re-tacked, Trpaineted and then they all re-broke. . .
just my 2p.
I love 3.0 dales I really do (and ride a 2.8 to work every day), but unfortunately, I'd say "wall art"/ garage queen, and scour ebay for another :cry:

 

[clockworkgazz]

Have done, but no. I design aeroplanes and parts for aeroplanes.

Yes, you could get it welded, but that would anneal what is a solution heat treated frame. It needs to be heat treated again after welding (so up goes your paintwork), and it needs to be supported in heat treatment or the stays stress releve and bow.
You can leave it to naturally age harden, and it will be ok in 150 years or so.
In the early-mid 1990s when ally frames were still pretty high-zoot, as shop I worked in got T J Quick in south london to tack up some botched 'dales and in his words "it'll break again". And they all did (no heat treatment). And as discussed on a klein thread in ebay watch just recently, the same was going on with backdoor kleins out of fusion that were being split bu USE shims that were too short. Re-tacked, Trpaineted and then they all re-broke. . .
just my 2p.
I love 3.0 dales I really do (and ride a 2.8 to work every day), but unfortunately, I'd say "wall art"/ garage queen, and scour ebay for another

Thanks for that, I have looked at a few internet posts that say that the tig welding destroys the heat treatment process as you point out.

They then say that you would need to re-do this heat treatment- which I asumme is not economical/practical for a welder to do- the upshot is the frame is repaired but now just as likly to fail due to the loss of strenght the welding process produces? Given the location of the crack, if this is correct then TIG welding without the heating/slow cooling process is not really a solution is it, or have I got the wrong end of the stick?

cheers

Gary

 

[bontyfiend]

There seem to be discussions about materials/failures etc. quite regularly on here. There's a book by a chap called J E Gordon called The New Science of Strong Materials: Or Why You Don't Fall Through the Floor. I'd highly recommend it for anyone interested in how steel/ti/carbon/aluminium behaves, why, and what the consequences are.

Sorry clockworkgazz, this doesn't help you with your crack, except to explain why it's there