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broken swing arm
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Posted by: hotrodbelair

just talked to a buddy of mine and he stripped down his 250r cause there was some cracks in his frame. he said his swing arm is nearly broken in half. but the way he explaind it to me it sounds like its just cracked almost all the way around he says hes gonna weld to where it will last him till next spring when he gets more money to buy a new swingarm. u think it will hold up for ice racing if he just welds it back together? im goin over there tommarrow to go and look at it ill get more info on it.

Posted by: JTRtrx250r

If he finds a good welder it'll hold up. I know a dude that had a stocker shortened and he ran it for MX for yrs catching all kinds of air, so I think for ice racing it would be ok. Of course a new swinger would be best

Posted by: 250R-Dee

Just make sure the welds penetrate properly. It will probably be best to ARC or TIG the cracks. MIG is better than nothing but the other two give better penetration.

Posted by: fireburns99

You cannot use an ARC welder for anything on a frame. Arc welders create too much heat leaving you with a brittle weld. Yes they are easy to get good penetration with, but it will put too much heat throught the rest of the swingarm.
TIG Welding would be the preferred method, but MIG is almost just as good for this purpose. Mig would be the easiest and give the best penetration out of the two, and if done right would work fine.

Posted by: hotrodbelair

yea hes gonna use the mig on it. just wasnt sure if welding a swingarm would hold up.

Posted by: XCredrider

i was told mig wasnt good for aluminum? maybe.. .idk much about welding so enlighten me

Posted by: brian350rx

is it aluminum or mild steel?

Posted by: hotrodbelair

steel

Posted by: fireburns99

First of all depending on what year the swingarm is, it may not be aluminium. The 86-87 were steel. Which makes the MIG process extremely easy. And make sure that you cut a "V" into the area that you are going to weld. It will help make a cleaner weld and give better penetration. You can do this by taking a small grinder and holding it on edge and just kind of folling the crack. You need to be careful not to make it so deep that you go all the way through, but deep enough that it helps with the penetration.

MIG is the best all around welding process. TIG is great for aluminium, and in situations where strength is a must(The NHRA now requires all roll cages and welds be made by the TIG process). The problem with TIG welding is how expensive the equipment is, and how difficult it is to learn to weld using the TIG process. You can weld aluminium with a MIG, you just need to change the wire,and i think reverse the polarity(i will have to check my MIG). The thing with aluminium is that you have to clean it extremely well before welding. Aluminium gets a coat of oxidation on it when sitting so it is neccesary to clean it with a wire brush before welding. If you don't the oxidation will inhibit the welders ability to penetrate leading to weaker welds. The other thing that makes welding aluminium difficult is the fact that when you weld aluminium you can't see the weld puddle, because the melting temperature is much lower than steel. Meaning the puddle doesn't turn to that molten metal color.

Posted by: fireburns99

Then the MIG will be just fine, and it should hold up fine while ice racing. Just make sure to prep the surface really good before you start welding.

Posted by: brian350rx

TIG is the best BY FAR
MIG will work fine for your application

Posted by: fireburns99

I agree brian. I love my TIG setup, i'm just not sure how good it would be with someone in-experienced using it. I had difficuly picking it up.

Posted by: brian350rx

exactly - TIG should be done by someone who knows what they're doing

Posted by: hotrodbelair

ill talk to him about using the tig on it. hes a pretty good welder but never seen him use a tig before. so tig and mig would be the better ones but tig would be the best right

Posted by: fireburns99

exactly...But he shouldn't try and TIG weld it unless hes competent with the TIG welding process.

Posted by: hotrodbelair

hes gonna have somebody else tig it for him he knows someone that knows how to use a tig. thanks for the help guys.

Posted by: baker250r

i got a swingarm i could sell him for a good price... its Ace Fabrication swingarm... only lookin for $200 if his R is 88-89 chassis, it will bolt right up.

Posted by: hotrodbelair

its an 86. will it still bolt up with a little modification.

Posted by: baker250r

if you torch/grind out where the motor goes... yea

Posted by: LT250Racer609

the same exact thing happened to me....i have a Lonestar -1 swingarm and i nearly cracked it in half....the crack was on the right side right above the brake caliper and it went all the way around...the thing that really sucks is that my swingarm is chrome...i had my uncle weld a plate all the way around it