kona uhu frame crack

[badger1]

hi this is my first post so hello
i have a kona uhu 1997 green i bought it to keep myself busy over crimbo
i have stripped the rear suspension and found the frame at the rear connecting lobes have cracks and need welded my question is what is the rear part of the frame made from as the sticker says the three main tube are easton elite 7005 aluminium ! and doesn't mention the rear and i cannot find out anywere .

 

[BG]

Looks exactly like the one I used to own... right down to where mine cracked too! Mine died within warranty so I managed to get a new seat stay from the importers here in Australia. It wasn't an exact match (it was black and had a canti cable stop on it so I figured it was from an earlier mode)l. Once it was fixed I promptly sold it. Loved to look of the frame - especially the colour, but always found the rear flexy and a bit 'wooden' even with a coil shock.

There was a thread on here from not too long ago that shows how someone had welded up this sort of crack. have a trawl or try searching and you may find it too. Good luck.

 

[stauqmuk]

just looking at the welds I'd go 99% that its aluminum but the old magnet test can prove or disprove steel. I think everyone would agree that the rear end being Ti would be ridiculous so slap a magnet on the stays, if it sticks they're steel if not aluminum.

 

[BG]

Oh yeah they're aluminium... not Easton that I know of though.

 

[EarlofBarnet]

Quite a few older Kona's seem to have cracked there. Bit of a shame, looks a nice bike.

 

[ollyb83]

mine cracked in the same place, i karma'd mine on here and Gruff won it.

heres a link to Gruffs build thread.

http://www.retrobike.co.uk/forum/viewtopic.php?t=163225

 

[badger1]

thanks for the input guys im a bit fed up ive found the cracks but part of the fun trying to resolve it i suppose
i do have a mate thats a welder, alu tig as well but he asked what alu it is 7005 or 6061 as the latter requires pre and post heat if im reading info correct and 7005 can be done at normal temp, any-one correct me on this?
has any-one tried making the frame section out of steel!!?

 

[Gruff]

Hi Badger,

I can confirm that the front end is Easton but i can't find what the back end is made from :?

The new stay ends i had made were welded on conventionally, without heat treating.

I'll have to wait till its built to see if they hold up

 

[badger1]

hi gruff
ive seen what you had done and it looks good im not sure if just welding it is the best way forward or getting new parts done the same as you
only tonight i have been talking to my father in laws next door neighbour and he has lathes and a miller in his garage and tells me he could make them if i need them so first i will have to show my welder mate and see what he thinks :?

 

[Anthony]

I don't know this for a fact, but I strongly suspect that the stays were made from 7005, but possibly not Easton Elite 7005. The 1997 specs just say:

· Easton Elite tubing.
· Tubing wall thickness: Top - 1.3/.9/1.3mm, Down - 2.2/1.0/1.5, Seat - 2.54
· Cold-forged, one piece aluminum dropout for high strength and excellent derailleur function.
· Cold forged aluminum swingarms for torsional rigidity.
· Made for 27.0mm seat post, 31.8mm front derailleur, 68mm bottom bracket, & 1-1/8" headset.
· Made with US-made tubing.

US consumer protection law is quite strong, so I think they would have a hard time justifying the Uhu stays being made from anything other than US-made tubing, either Easton Elite or very similar to it.