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broken frame Iron Horse MKIII

Nov 8, 2011
10
0
I welding my broken frame 2 times,
frame broke after 5 ride.
Is it special method to welding this part? I don't why this frame broken in this place?DSCF3537.JPGDSCF3925.JPGDSCF3939.JPGiron horse.JPG
 

Huck Banzai

Turbo Monkey
May 8, 2005
2,526
21
Transitory
Ive always been told that once aluminum breaks - done; barring a whole lot of gusset work, time to look for a new ride.

Glad to be proven wrong tho.
 

dilzy

Monkey
Sep 7, 2008
567
1
You need to provide some gussetting. What's happening is the frame stiffness at the weld junction is increased dramatically, concentrating all the stress right at the weld heat affected zone, so you need to provide some triangular gussets that provide an increase in stiffness gradually towards the joint.

It is perfectly possible to make it work and never break again. I've gusseted and welded my 06' spec enduro non-drive side chain stay after breaking the original, then the new one with the specialized gusset in the wrong place and after that cracked, now it's holding fine after almost a year.
 

Da Peach

Outwitted by a rodent
Jul 2, 2002
12,631
2,007
North Van
You mostly hear about cracked rear triangles on those bikes, it should be easy to find an un-cracked front triangle.
This is a good point. I bet there must by a ton of fronts to be had...

I've managed to not break mine yet... *knocks wood*

They're great bikes.
 

dilzy

Monkey
Sep 7, 2008
567
1
Im a multi-tasker, are you done being made to look like a gigantic blubbering idiot in the V10 thread already? Trying to look like an asshole everywhere huh?
You mean done with a perfectly civil exchange in the v10 thread? No I'm probably not. Not sure how it makes me a giant blubbering idiot arsehole, but I'm sure you would know.
 
Nov 8, 2011
10
0
DSCF3537.JPG
This is a good point. I bet there must by a ton of fronts to be had...

I've managed to not break mine yet... *knocks wood*

They're great bikes.
I don't know, mayby 2 parts are made from another material???
This place where frame broken in my iron horse is strange :/
I weight 200 lbs,mayby it is reason that frame broken?
 
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dilzy

Monkey
Sep 7, 2008
567
1
This poor dude is going to seriously think that it's cast iron...It's not swimfan, it's all aluminium, the bit your pointing to is just billet machined or forged then finish machined, not sure which.

Either way, it cracked due to the reasons I mentioned. In every case I've seen, welded tubing like that cracks at the edge of the heat affected zone.
 

blackohio

Generous jaywalker
Mar 12, 2009
2,797
120
Hellafornia. Formerly stumptown.
Does it have the ironhorse shock sock still on it. That's how you can tell if its installed correctly. The problem with welding aluminum to cast iron is you have to get the panametric bearing properly align along the hydrocoptic marzelvein so that you essentially eliminate side fumbling during dual synching of the phase detractors. ****s not easy. Not even for trained welders.
 

dilzy

Monkey
Sep 7, 2008
567
1
That's the way, be a dick to a guy for whom English is obviously a 2nd language. 'k'n oath and you think I'm a blathering idiot.
 

slimshady

¡Mira, una ardilla!
Dec 20, 2007
2,712
774
La Plata, Argentina
Happened to me too about six months ago. First the rear triangle cracked at the usual spot (in the rear triangle, where the right chainstay meets the vertical tube), and then at the very same spot as yours. A competent welder has fixed mine, previously heating the zone to prevent any stress damages. He also heat-treated the zone after welding it (not the whole front triangle, which should have been the right thing to to, but we weren't unable to do it for obvious reasons).

As I said, so far it's been hanging on... But I don't know how long it will last.

When the first crack appeared, I started searching online for similar cases, and stumbled upon a thread on MTBR where a guy who used to work for IH detailed failures every frame would show, due to improper welding or poor QC. This was because IH changed many times their frame suppliers in the last three years of its existence. Sadly, I couldn't find that thread again. It would have been useful, since you could mix and match front and rear triangles from different years to try to get a solid combination...
 
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Nov 8, 2011
10
0
Happened to me too about six months ago. First the rear triangle cracked at the usual spot (in the rear triangle, where the right chainstay meets the vertical tube), and then at the very same spot as yours. A competent welder has fixed mine, previously heating the zone to prevent any stress damages. He also heat-treated the zone after welding it (not the whole front triangle, which should have been the right thing to to, but we weren't unable to do it for obvious reasons).

As I said, so far it's been hanging on... But I don't know how long it will last.

When the first crack appeared, I started searching online for similar cases, and stumbled upon a thread on MTBR where a guy who used to work for IH detailed failures every frame would show, due to improper welding or poor QC. This was because IH changed many times their frame suppliers in the last three years of its existence. Sadly, I couldn't find that thread again. It would have been useful, since you could mix and match front and rear triangles from different years to try to get a solid combination...
have you got any pictures (rear triangle cracked )
 

wiscodh

Monkey
Jun 21, 2007
783
83
303
That's the way, be a dick to a guy for whom English is obviously a 2nd language. 'k'n oath and you think I'm a blathering idiot.
hey buckshot. He obviously didnt listen to me when i told him his re weld failed beacuse there is no treatment to the weld area.

Even if his engrish isnt steller, when he disregards correct info, im going to go off on a tangent and be a wanker.

I think it might be carbon fiber. You should really lay off the east coast rox. I hear if you do the hand flex test you can find out really quickly.
 

ldw222

Monkey
Jun 16, 2009
170
0
Rochester, NY
have you got any pictures (rear triangle cracked )
this picture isn't from my frame but i cracked mine a little while ago, asked around, and a guy on here sent me this...Gusset.jpg

i didn't try it yet...i just bought another mkiii on pinkbike and am going to get the old one welded after i get the new one together.
 
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slimshady

¡Mira, una ardilla!
Dec 20, 2007
2,712
774
La Plata, Argentina
this picture isn't from my frame but i cracked mine a little while ago, asked around, and a guy on here sent me this...View attachment 112591

i didn't try it yet...i just bought another mkiii on pinkbike and am going to get the old one welded after i get the new one together.
That doesn't work. The vertical tube is butted, meaning the wall gets thinner as you go far from the weld, so it will eventually crack right after the gusset... The one in this picture was re-welded two times, each one with bigger gussets...



EDIT: I just found the thread on MTBR I mentioned before, where a former employee details the welding failures for each model.
 
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