Originally Posted by
Chombi
It would be interesting to do the forensics on why the crack developed. Could the chainstay bridge next to it had something to do sith it? What does it look like from the other side of the stay, next to the wheel? Is this something that happens to other Al frames?
Chombi
There is another crack forming on the other side. You can actually kind of see it in the picture forming from the topside working its way down. I'm a pretty big guy and generate a bit of power. My bet is the constant flex caused that point to fatigue until cracking. This isn't the first frame I've broken in this manner. I had a Lemond Nevada City that I cracked at the dropout on the driveside chainstay. Perhaps the Altron was just too rigid...
Originally Posted by
puchfinnland
FIX IT!!!!
strip down the frame.
remove all paint about 2 inches on both sides of the weld.
take it to an aluminum welder with a TIG welder.
the way i would do it is:
replace the tube or
get the measurement recorded.
cut straight thru the crack so a good penetration weld can happen
slip a short piece of aluminum inside the tube from the bb hole to create a liner.
drill some holes before and after the crack-in these holes the liner can be attached by welding
this also re-inforces the area
weld up the crack and smooth it down.
should be one hour of a welders time.
I am sure frank the welder will be around soon-ask him!
Originally Posted by
qcpmsame
Wow, you at least have a frame to show someone that does not believe your "I was mashing so hard up that hors categorie climb I snapped the stay" story. That is a beautiful frame/bicycle.
+1 for investigating the cause of the failure. I'd like to see the stress pattern and the propagation pattern of the riser(s) and I'll wager a good welder could weld that stay very well. Let a skilled welder TIG weld it with a good wire and gas shield and really good preparation/measurements. I am with Puchinfinnland on letting Frank see this thread and the pics. I would trust his judgement without reservation.
Bill
interesting
I was under the impression that repairing aluminum frames wasn't a great idea and the repaired area was likely to fail again. Even with it cracked on both sides right at the bridge is this feasible?