Urban DH
Likes Bikes and Dirt
its simple in theory to just cut it out and weld a new piece in, as for executing this task, well thats another story, by a pro, it can be done, DO NOT atempt it your self
Frame Repair Thoughts ? (I knew it was to good to be true)
- Thread starter heavyp
- Start date
That's what I thought, seems simple but its probably not and may not even be the right thing to do.
Urban DH
Likes Bikes and Dirt
this is true, maybe weld up the cracks and weld a new rail around the existing one
heavyp
You heard it here first
I put this on a forum in England and I found this and interesting response
"yeah any welder could fix that no worries.
having spoken to some one who wleds up space frame aluminium chassis' for racing land rovers, he was shocked to hear how many cyclists are worried about re welding alloy frames. You may not get it looking exactly the same easily and as strong as original but it will be very close."
This had me think my brother bought a bike in 1997/98 it was a full suss kenesis XC bike he cracked one of the rear chainstays, are next door neighbour was a making motorbike exhausts at the time and re-welded if for him and its still being road today as a DH bike and he weighs almost 100kgs. Ill get it clamped and welded and see how I go if it goes completely Ill try taking the brace out and getting a new one welded in.
"yeah any welder could fix that no worries.
having spoken to some one who wleds up space frame aluminium chassis' for racing land rovers, he was shocked to hear how many cyclists are worried about re welding alloy frames. You may not get it looking exactly the same easily and as strong as original but it will be very close."
This had me think my brother bought a bike in 1997/98 it was a full suss kenesis XC bike he cracked one of the rear chainstays, are next door neighbour was a making motorbike exhausts at the time and re-welded if for him and its still being road today as a DH bike and he weighs almost 100kgs. Ill get it clamped and welded and see how I go if it goes completely Ill try taking the brace out and getting a new one welded in.
chrisrotorhead
Squid
Talk to and engineering workshop in your local area. any fitter and turner or sheet metal fabricator or boiler maker with a 7000 of 6000 series aluminium welding ticket (almost all will have a ticket to weld it) will be able to do it no worries. In my experience of talking to these professionals they aren't bothered that its aluminium or "aircraft grade" they have spent years mastering their trade and welding things a lot trickier than this stuff. Besides who do you think made it in the first place. A rocket surgeon in the Swiss alps? No it was a Taiwanese guy shown the basic steps at age 12 and now 13 years old he has got the hang of it.
No you can't do it at home unless you have 3phase power and a AC/DC inverter TIG welder with the right gas, welding rods and skill.
Welds are generally stronger than the parent metal they welded to.
Relax look in the phone book....er I mean google then phone around and ask local engineers to point you in the right direction.
No you can't do it at home unless you have 3phase power and a AC/DC inverter TIG welder with the right gas, welding rods and skill.
Welds are generally stronger than the parent metal they welded to.
Relax look in the phone book....er I mean google then phone around and ask local engineers to point you in the right direction.
i must suggest NOT taking it to nicom engineering, ive take my racebike (m/c road racing) to him and have had VERY bad results, and ZERO after service with it, to correct the issue.
dave kellet (07) 3290 2811 is the man i use for all my motorcycle cracks and bends i tend to accumulate through a racing season and is located in slacks creek
im a sheetmetal fabricator myself, and usually do pushies and minor myself, but i leave the motorcycle stuff to him tho. and have no problems putting faith in the work he does at over 270kmph.
give him a call. his pricing is fair too
cheers.joe.
dave kellet (07) 3290 2811 is the man i use for all my motorcycle cracks and bends i tend to accumulate through a racing season and is located in slacks creek
im a sheetmetal fabricator myself, and usually do pushies and minor myself, but i leave the motorcycle stuff to him tho. and have no problems putting faith in the work he does at over 270kmph.
give him a call. his pricing is fair too
cheers.joe.
SummitFever
Eats Squid
Your swingarm is probably made of either CU92 or Aluxx aluminium. They are both grades of 6000 series heat-treatable aluminium. Exact type is open to some dispute as Giant doesn't really provide specs, but its probably 6013 and 6061 respectively. They are not rocket science to weld. Welding will result in an estimated 30-40% heat-caused weakening at the weld/HAZ compared to the heat-treated parent material. If you're not going to (or unable) to heat treat the swing arm after the weld, then you can just beef things up to compensate for the 30-40% strength loss in that part. ie. over engineer the repair, but taking care not to heat the rest of the part such that it becomes annealed. This is why the gripsport repairs I've seen feature really beefed up plates/braces etc.
Those Giant swing-arms have a habit of cracking at that brace. The tube really needs to be much thicker wall to cope with the twisting forces on the swingarm. See how much clearance you've got and make the brace bigger. However, this may just cause the swing arm to crack in a different place as the stress is transfered somewhere else.
Those Giant swing-arms have a habit of cracking at that brace. The tube really needs to be much thicker wall to cope with the twisting forces on the swingarm. See how much clearance you've got and make the brace bigger. However, this may just cause the swing arm to crack in a different place as the stress is transfered somewhere else.
Urban DH
Likes Bikes and Dirt
wrong you only need a 15amp plug and a dc tig welder with some heliarc gas and some 2% silicon rods if you dont know what it is and she'll weld right up good as new! had a bloke at work tig some new drop out into my dj frame, 3/8th plate instead of 6mm, must stronger, way better! just wled her up an weld a small plate over to top and bottom of the tube and she'll be right!
What the hell ? There's some very average technical advice being thrown around here , but this takes the cake. DC on aluminium hey ? Good luck with that.
Send it to Grip or someone locally that you know has the knowledge and ability to do the repair. It's not rocket science but need to be done right or don't bother at all.
Urban DH
Likes Bikes and Dirt
thats not average tech advice thes correct advice to weld alli all you need is a 15amp socket and a dc tig, you can ONLY tig with dc other wise its an ac current, think about it dc, direct current, ac alternating current, you can weld if your power fluctuates, you can plug it into an ac socket but you're machine all be it not a dc converter will have pre flow, post flow and high frequency control so it is just the same as dc, a constant direct current coing out of the tip, have a look at alli welding basics mate, you will be best of welding it with a dc machine for a bike frame, learn your shit and think about it
http://www.weldcraft.com/2006/11/basics-for-tig-welding-aluminum/
SummitFever
Eats Squid
I think you'll find standard practice is for tig welding alu is with AC. The current reversal is required to "clean" the oxide off the base material. The article you refer to mentions DC welding only in the context of using pure helium as the shielding gas. It also refers to the requirement of "exceptional cleanliness". I have never actually come across anyone using DC Tig to weld alu. DC is used for TIGing steel, stainless and related alloys . I have seen a casting flaw in a large alu die built up with a DCEN alu rod using a stick welder (SMAW).
I agree with Spinner. Just send it to Gripsport and get it sorted.
So the last 30 years I have spent in the trade as a boilermaker ,,,,, Ive been doing it wrong ? Shit ! Thanks for the tip buddy , I feel such a tool !
Urban DH
Likes Bikes and Dirt
i was taught to tig alli with a dc tig with helliarc gas, so unless the act tafe teachers and chris the welder in the work shop (a welder of 40years) are in compotent i think it would be fine to tig an 6061 frane with a dc tig and hellium, thats how i would do it, its what works for me but if you know best i'm sure you can do it a number of different ways!
:focus: either weld it up and chuck some plates over it for extra strength or sent it some where
:focus: either weld it up and chuck some plates over it for extra strength or sent it some where
heavyp
You heard it here first
I don't want masses of extra material welded around where its broken it will look like shit, I think im just going to ride it out and see how I go as Karl (The green atx with the same crack pictured a few pages back) has been doing with no issues as yet, and I don't think ill be hitting to many jumps riding to Coles to get bread and milk.
Anyone got a spare ATX one/DH Team chainstay ?
ray:
Anyone got a spare ATX one/DH Team chainstay ?
ray:
Mywifesirrational
I however am very normal. Trust me.
Good find, is that an old AC chain guide in the pics?
heavyp
You heard it here first
Yeah AC goodness, I have 3 now haha 2 are just going to be used for parts thou as there not in that great a shape.