K2 / Proflex Riders Group
General => Tech Forum => Topic started by: rapiddescent on October 09, 2008, 04:12:15 am
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I've got a 2001 Razorback RS that has been used predominantly as a singlespeed bike - it's been in 3 singlespeed world cup races and many of the Euro and UK singlespeed races...
I was dismantling the bike to get it ready for a new powdercoat when I noticed a thin crack under one of the forged strut braces. Then, as I unscrewed the other side - it fell off in my hand!!! Bike is basically written off!
So I've got a strut that is broken off
(http://www.proflex.demon.co.uk/photos/855heads/strutbroken.jpg)
and cracked on the other side:
(http://www.proflex.demon.co.uk/photos/855heads/strutmptbrokenyet.jpg)
It looks like cold forged so I'm going to find a friendly welder who can put it back and bolster it all up.
If anyone has any contacts at K2 Bike, please get in touch so I can see if they have any spares (unlikely now). Yeah, I don't have any K2 Bike contacts anymore - they're all long gone...
cheers
callum
rds
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I took the strut into some old guys I know who are expert welders - they say that it is too small and is not weldable/brazeable - the end piece is some sort of forged graphite alloy and won't fix. Also, they said the otherside was very close to snapping off so I'm lucky it didn't happen whilst riding...
also, if you have a razorback - look closely at the strut ends for cracks. I only have 1 working proflex left now. A 97 beast that has slicks on it for riding to work.
so RIP my razorback. here's a picture of us in better times!
(http://www.proflex.demon.co.uk/photos/855heads/razorbackss2.jpg)
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:-[ RIP (rust in peace)
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Thats easily salvagable :)
Make a new fork end, cut off the origonal and weld new fork end onto strut end,
this would be as strong as it was when new.
Simon.
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well, this is my next plan. I'm going to get a copy made of the fork end that still works (CNC'd from billet Al) and then get that rebrazed on. Both fork ends are identical so I'll get a handful of them made. If anyone else has a razorback rs, please check yours.
will report back.
callum
rds
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is your razorback to old for warranty???
im not suggesting for one minute that you dont know how to tighten a bolt up but could this be from
over tightening???
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sadly all the Uk warranties are null and void after the distributor went 7 years ago.
Its strange because that bolt was never touched in its lifetime - the first time was to remove it for the powder coating I had booked it in for. Under a magnifying glass the crack in the other leg is quite old, there is mud in the crack. It looks like its been there for since last before the SingleSpeed UK race.
I don't really jump much but I'm wondering if I had a heavy hit in that race - I don't remember one.
callum
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weird how they have broke in the same place and both internal side's.
just looking at the old girl and the rear pivot on the oldies seems to be a u shaped
piece welded to the fork tube..perhap's they need a little flex...or the r/back is just taking all the strain on the inner side's????
forged stuff is prob to brittle....
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weird how they have broke in the same place and both internal side's.
just looking at the old girl and the rear pivot on the oldies seems to be a u shaped
piece welded to the fork tube..perhap's they need a little flex...or the r/back is just taking all the strain on the inner side's????
forged stuff is prob to brittle....
I would of thought less flex the better as its running a pull shock that is also structurally anchoured on the frame.
I agree probablely the material is to brittle or just age fatiqued.
Simon.
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Hi there. I am just back from the AWS show in Las Vegas. ;D
Anyway, I just saw your post. I certainly think that the right welder can repair that strut. Notice that the clevis section was welded by the factory, so it is certainly weldable. As far as being too small, hogwash. The only thing that would be subpar would be the heat treat, but you could weld and cold water quench to bumpstart the aging process, then let it sit for a week to shake out.
A typical repair weld like that is minimum charge, that includes wire wheel the paint off, bevel, and water quench immediately after weld(within seconds). The blending, fitting or filing is up to you. Go find someone that can full penetration weld with 5356, and you have your man.
Terry
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If by strut you mean the piece that holds the pull shock then I say... would you like a blue one or a green one? I happen to have both. I don't know if they are one size fits all or not buy you are welcome to one of them. I'm in the US. You pay the freight and it is yours. Just let me know dude.