Aluminium Bicycle Frame - weld crack repair

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Aluminium Bicycle Frame - weld crack repair - guidance needed

Aluminium Bicycle Frame - weld crack repair - guidance needed

Author	Message
tomBIKE	t tomBIKE posted 4 Years Ago HOT Topic Details
t Group: Forum Members Posts: 4, Visits: 12	Hi all, I purchased a lovely bike 2nd hand, and it has developed (or was sold with) a crack on one of the seat stay welds. I have no chance of a warranty, and ebay cant help. I spoke in person to my very reliable local bike shop who offered some hope. Basically I don't want to scrap the frame, I like fixing things and quite frankly I cant afford a new frame. They suggested that 1. the crack isnt too bad, and many people would ride on it no problems..I'm not one of those people. This is paraphrasing a long conversation, with a frame builder. 2. Frame builder suggested that a carbon support/'lug' could be created using Carbon Fibre Tow and epoxy of some sort. He used the examples of many bamboo bikes being created using similar materials. The pic below gives some idea of what the crack looks like - but it hasnt reproduced that well here. lower section of left weld area. I think what Im trying to achieve is not a full repair like a weld might provide (probably unachievable in aluminium) but a bit of a safety net in terms of strength support, and if the tube was to shear, some sort of control of that - i.e. not stabbing into a thigh or similar! Does anybody here have any experience of a similar repair, i.e. a fairly complex shape, aluminium. If so - what materials might be best, in terms of weight of Tow and epoxy type, and or -is it even worth a go?
	Reply Like 3
Replies
Lester Populaire	L Lester Populaire posted 4 Years Ago HOT Post Details
L Group: Forum Members Posts: 311, Visits: 13K	+x Steve Broad - 6/12/2020 5:51:19 PM Why not simply get someone who can TIG weld to repair it properly? Bike frames are usually made from 6000 series aluminum that needs heat treatment after welding.
	Reply Like 2
Steve Broad	Steve Broad posted 4 Years Ago HOT Post Details
Group: Forum Members Posts: 408, Visits: 4.1K	+x Lester Populaire - 6/12/2020 7:21:59 PM +x Steve Broad - 6/12/2020 5:51:19 PM Why not simply get someone who can TIG weld to repair it properly? Bike frames are usually made from 6000 series aluminum that needs heat treatment after welding. If the frame is made from a T6000 series aluminium, I agree that ideally it should be heat treated after welding. However, the frame has already cracked so isn't exactly a brilliant or strong design to start with so welding up the crack and reinforcing with a welded on sleeve will do a better job than a bodge with carbon fibre. IMO
	Reply Like 3
Lester Populaire	L Lester Populaire posted 4 Years Ago HOT Post Details
L Group: Forum Members Posts: 311, Visits: 13K	+x Steve Broad - 6/12/2020 11:32:16 PM +x Lester Populaire - 6/12/2020 7:21:59 PM +x Steve Broad - 6/12/2020 5:51:19 PM Why not simply get someone who can TIG weld to repair it properly? Bike frames are usually made from 6000 series aluminum that needs heat treatment after welding. If the frame is made from a T6000 series aluminium, I agree that ideally it should be heat treated after welding. However, the frame has already cracked so isn't exactly a brilliant or strong design to start with so welding up the crack and reinforcing with a welded on sleeve will do a better job than a bodge with carbon fibre. IMO I have seen a lot of welded frames and never anything that worked. Especially at the transition there you can't put a sleeve over it either...
	Reply Like 3
Steve Broad	Steve Broad posted 4 Years Ago HOT Post Details
Group: Forum Members Posts: 408, Visits: 4.1K	+x Lester Populaire - 6/13/2020 6:43:49 AM +x Steve Broad - 6/12/2020 11:32:16 PM +x Lester Populaire - 6/12/2020 7:21:59 PM +x Steve Broad - 6/12/2020 5:51:19 PM Why not simply get someone who can TIG weld to repair it properly? Bike frames are usually made from 6000 series aluminum that needs heat treatment after welding. If the frame is made from a T6000 series aluminium, I agree that ideally it should be heat treated after welding. However, the frame has already cracked so isn't exactly a brilliant or strong design to start with so welding up the crack and reinforcing with a welded on sleeve will do a better job than a bodge with carbon fibre. IMO I have seen a lot of welded frames and never anything that worked. Especially at the transition there you can't put a sleeve over it either... But I can't see a carbon repair working either, bearing in mind the stresses involved at this joint (they cracked the aluminium). Yes, I know that bikes are made from carbon, but that is a completely different ballgame to wrapping a cracked joint with the stuff. I don't think that I would feel save riding a bike repaired that way.
	Reply Like 2
tomBIKE	t tomBIKE posted 4 Years Ago HOT Post Details
t Group: Forum Members Posts: 4, Visits: 12	+x Steve Broad - 6/13/2020 11:28:16 AM +x Lester Populaire - 6/13/2020 6:43:49 AM +x Steve Broad - 6/12/2020 11:32:16 PM +x Lester Populaire - 6/12/2020 7:21:59 PM +x Steve Broad - 6/12/2020 5:51:19 PM Why not simply get someone who can TIG weld to repair it properly? Bike frames are usually made from 6000 series aluminum that needs heat treatment after welding. If the frame is made from a T6000 series aluminium, I agree that ideally it should be heat treated after welding. However, the frame has already cracked so isn't exactly a brilliant or strong design to start with so welding up the crack and reinforcing with a welded on sleeve will do a better job than a bodge with carbon fibre. IMO I have seen a lot of welded frames and never anything that worked. Especially at the transition there you can't put a sleeve over it either... But I can't see a carbon repair working either, bearing in mind the stresses involved at this joint (they cracked the aluminium). Yes, I know that bikes are made from carbon, but that is a completely different ballgame to wrapping a cracked joint with the stuff. I don't think that I would feel save riding a bike repaired that way. Yep - agree with both on this - think the frame is a really tricky repair either way, and I'm not sure either way is going to be worth the time/money and eventual probable risk. i.e. its broken! Really appreciate the input from both points of view - exactly what I was looking for. Its been a stressy couple of days since the discovery of the issue. But I have recovered and currently looking for a new frame with a warranty!
	Reply Like 2
Lester Populaire	L Lester Populaire posted 4 Years Ago HOT Post Details
L Group: Forum Members Posts: 311, Visits: 13K	+x tomBIKE - 6/13/2020 11:35:11 AM +x Steve Broad - 6/13/2020 11:28:16 AM +x Lester Populaire - 6/13/2020 6:43:49 AM +x Steve Broad - 6/12/2020 11:32:16 PM +x Lester Populaire - 6/12/2020 7:21:59 PM +x Steve Broad - 6/12/2020 5:51:19 PM Why not simply get someone who can TIG weld to repair it properly? Bike frames are usually made from 6000 series aluminum that needs heat treatment after welding. If the frame is made from a T6000 series aluminium, I agree that ideally it should be heat treated after welding. However, the frame has already cracked so isn't exactly a brilliant or strong design to start with so welding up the crack and reinforcing with a welded on sleeve will do a better job than a bodge with carbon fibre. IMO I have seen a lot of welded frames and never anything that worked. Especially at the transition there you can't put a sleeve over it either... But I can't see a carbon repair working either, bearing in mind the stresses involved at this joint (they cracked the aluminium). Yes, I know that bikes are made from carbon, but that is a completely different ballgame to wrapping a cracked joint with the stuff. I don't think that I would feel save riding a bike repaired that way. Yep - agree with both on this - think the frame is a really tricky repair either way, and I'm not sure either way is going to be worth the time/money and eventual probable risk. i.e. its broken! Really appreciate the input from both points of view - exactly what I was looking for. Its been a stressy couple of days since the discovery of the issue. But I have recovered and currently looking for a new frame with a warranty! If the warranty doesn't lead anywhere have a look at commencal. they usually have really good deals on frames from last season. you should get a very nice frame for relatively little money. Just make sure you can transfer your parts over (same frame standards).
	Reply Like 3
tomBIKE	t tomBIKE posted 4 Years Ago HOT Post Details
t Group: Forum Members Posts: 4, Visits: 12	+x Lester Populaire - 6/13/2020 3:19:15 PM +x tomBIKE - 6/13/2020 11:35:11 AM +x Steve Broad - 6/13/2020 11:28:16 AM +x Lester Populaire - 6/13/2020 6:43:49 AM +x Steve Broad - 6/12/2020 11:32:16 PM +x Lester Populaire - 6/12/2020 7:21:59 PM +x Steve Broad - 6/12/2020 5:51:19 PM Why not simply get someone who can TIG weld to repair it properly? Bike frames are usually made from 6000 series aluminum that needs heat treatment after welding. If the frame is made from a T6000 series aluminium, I agree that ideally it should be heat treated after welding. However, the frame has already cracked so isn't exactly a brilliant or strong design to start with so welding up the crack and reinforcing with a welded on sleeve will do a better job than a bodge with carbon fibre. IMO I have seen a lot of welded frames and never anything that worked. Especially at the transition there you can't put a sleeve over it either... But I can't see a carbon repair working either, bearing in mind the stresses involved at this joint (they cracked the aluminium). Yes, I know that bikes are made from carbon, but that is a completely different ballgame to wrapping a cracked joint with the stuff. I don't think that I would feel save riding a bike repaired that way. Yep - agree with both on this - think the frame is a really tricky repair either way, and I'm not sure either way is going to be worth the time/money and eventual probable risk. i.e. its broken! Really appreciate the input from both points of view - exactly what I was looking for. Its been a stressy couple of days since the discovery of the issue. But I have recovered and currently looking for a new frame with a warranty! If the warranty doesn't lead anywhere have a look at commencal. they usually have really good deals on frames from last season. you should get a very nice frame for relatively little money. Just make sure you can transfer your parts over (same frame standards). +x Lester Populaire - 6/13/2020 3:19:15 PM +x tomBIKE - 6/13/2020 11:35:11 AM +x Steve Broad - 6/13/2020 11:28:16 AM +x Lester Populaire - 6/13/2020 6:43:49 AM +x Steve Broad - 6/12/2020 11:32:16 PM +x Lester Populaire - 6/12/2020 7:21:59 PM +x Steve Broad - 6/12/2020 5:51:19 PM Why not simply get someone who can TIG weld to repair it properly? Bike frames are usually made from 6000 series aluminum that needs heat treatment after welding. If the frame is made from a T6000 series aluminium, I agree that ideally it should be heat treated after welding. However, the frame has already cracked so isn't exactly a brilliant or strong design to start with so welding up the crack and reinforcing with a welded on sleeve will do a better job than a bodge with carbon fibre. IMO I have seen a lot of welded frames and never anything that worked. Especially at the transition there you can't put a sleeve over it either... But I can't see a carbon repair working either, bearing in mind the stresses involved at this joint (they cracked the aluminium). Yes, I know that bikes are made from carbon, but that is a completely different ballgame to wrapping a cracked joint with the stuff. I don't think that I would feel save riding a bike repaired that way. Yep - agree with both on this - think the frame is a really tricky repair either way, and I'm not sure either way is going to be worth the time/money and eventual probable risk. i.e. its broken! Really appreciate the input from both points of view - exactly what I was looking for. Its been a stressy couple of days since the discovery of the issue. But I have recovered and currently looking for a new frame with a warranty! If the warranty doesn't lead anywhere have a look at commencal. they usually have really good deals on frames from last season. you should get a very nice frame for relatively little money. Just make sure you can transfer your parts over (same frame standards). nice site - never heard of commencal - some interesting ideas.
	Reply Like 2