Forum menu
Following on from yesterdays can I get my sheared frame fixed thread
I've a 6000 series front triangle frame. Is post weld heat treatment a massive faff to find somewhere? Is it £££?
Can getting hairline cracks welded up make things worse at this point? Blowing holes? Making new stress risers? How good a welder does it require? etc?
I've small cracks in my front triangle. The most troublesome one being the top edge of the top tube where it meets the weld upto the headtube
[url= https://www.flickr.com/photos/29214358@N08/31364420662/in/dateposted-public/lightbox/ ][u]Theres a pic here, but I can't seem to hotlink anymore?[/u][/url]
There was a clear paint crack right over the top of the tube, I chipped the paint back and I think I can just see a hairline crack. I can't get it to show on a photo though. Macro isn't good enough on my camera
I'm at a point where I need to spend and source bushes/centres, bearings, a new chainstay, fix the dropper post and fork (£££ x2), pitted rotors and other sundries, so don't really want to be forking out if my frame is (shortly?) due scrapping?
Thoughts? Encouragement? Help?
In my non expert opinion I think you're in trouble
I think 6061 heat treatment is quite a big deal. Orange heat the bikes for 24 hours? But once its done then the welds and tubes are compleletly recrystalised to one structure. So that should mean that any new welding isn't a weak spot
But again amateur opinion but a crack in a weld doesn't seem like good news. Why has it cracked there. If you restore to how it was won't it crack again?
I think it was most likely down to partially casing a double with the front wheel. Nothing ridiculously harsh, just enough to send me the rider forward in the riding position with a jolt.
On False teeth, mbr, Coed-y-brenin
We get a lot of aluminium aerospace stuff heat treated at work. Vastly complicated and time consuming process including annealing. It will cost more than the frame is worth to do it properly. The welding is the easy bit.
Sorry ... as above.
It might not break more or it might just be a scratch rather than stress fracture,
Plenty of people will be getting new bikes or parts over mass and eBay the old bike/frame after ...7075 is even worse but getting it annealed after welding is going to be expensive I'd imagine...
Random thought might be to reinforce with a carbon fibre kit... if you don't mind the look after ?
Crack detection kit ?
Use this for testing welds etc.Bit messy but does what it says on tin, literally.
Read that back in the day Mountain Cycle used to heat treat the San Andreas (6016 aluminum) to T6 after welding and if they were misaligned after this they binned them as you couldn't straighten them again.
Tends to suggest that welding without then re-heat treating could be a problem and just heating aluminum could anneal it.
(I have a poor memory so this could be incorrect)