Looking for a little advice on this.

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I was hoping to get a little advice on it. I am working on a swingarm for a motorcycle and I am modding it a little. I started out with this.I then cut out the original shock mount for it because I will be using dual rear shocks and the arm was shortened. It now looks like this. After cutting out the shock mounts the arms sprung in some. I am not sure if it was 1 or both, I didn't get to check it out yet. I need to put some sheet metal back into it right in front of the wheel. It will be something like this. http://www.ebay.com/itm/Vintage-Aerm...-/230680236215  My question is would you try and get the arms back to where they were before the brace get put in or put it back into position and weld the brace in and then deal with any spring afterwards. I do have blanks that go into the eccentric holders and a bar that goes across that held them in place when they got welded in. When this is in everything can be held to where it was before the mount got cut out. It really would have worked out better if the arms would have sprung out instead of in but there is nothing I can do about it. Thanks.
Reply:Too bad you cut all the support away. You could have just cutoff the protrusions and covered it.
Reply:If you need to splay the two pieces out, a bottle jack comes to mind. Getting everything lined up right, that I can't help you with..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:Originally Posted by ezduzitToo bad you cut all the support away. You could have just cutoff the protrusions and covered it.
Reply:The more you weld in the harder it will be to get straight.once you weld the brace in will it bend in the right spot or will the brace affect the bend area. Maybe the brace can be welded such to use the shrinkage from the weld to help pull it into placeMillermatic 252millermatic 175miller 300 Thunderboltlincoln ranger 250smith torcheslots of bfh'sIf it dont fit get a bigger hammer
Reply:I work on bikes too. I suggest that you find an original at a junkyard so you know the correct geometry. Just having the end opened the correct amount doesn't guarantee that it won't be off-square and force the rear wheel to one side or the other...GravelThe difference between theory and practice is that in theory there is no difference.
Reply:Don't know what your welding experience is, mine isn't really much compared to a lot of people here, but I'd get it to the proper width first, plus 1/8inch. You will be welding on the inside of the tube arms which will tend to draw the ends back in some, hence the reason for the +1/8" starting position. Have you checked the pivot bushings and the axle clamps for being parallel? I set my swingarm up on a cast iron table saw top to measure for parallel and was a little surprised how far off they were. If they are off, now's the time to get them straight before you start adding more metal in thereLooking good so far..
Reply:Put it in place and weld it just like the pic and it won't pull. Just be sure you don't weld around the tube at the end of the brace.
Reply:It's been my experience, although I don't do motorcycles (all welding is basically the same though), that you have to deal with distortion at every juncture.If you don't correct distortion at each step, each part welded will add to, or magnify, the problem.  In addition your measurements will be off for each successive part welded to the assembly because you didn't bring it back to spec each time you welded.  You could wind up with an unuseable assembly."Any day above ground is a good day"http://www.farmersamm.com/
Reply:Don't worry about straightening it first. Put in the jig to get it straight and tack in the new crossmember. Weld the only top and bottom. Pull out the jig.When you weld the crossmember at the inside of the arms it will want to shrink and warp in, so in order to prevent this, put some pressure between the arms with something like a bottle jack. I'd guess spreading it by about 1/2" would be enough, then weld it up. Or, do like the swingarm in the ebay link was and as welderj suggested, and do not weld that part.Ian TannerKawasaki KX450 and many other fine tools
Reply:You are right, but it won't distort as long as all the welds are lengthwise and down the center of the tube and equal on both sides. It may pull up or down a bit since one side will be welded before the other but not together. He can minimize that by welding short welds and alternating sides while welding. Welding the end of the brace will give it a place to pull in tho and also weaken the tube which may be bad since the brace will end lower, or shorter, and there will be more stress because of that. He could minimize that by bringing his brace to a point or radius if he really wants to weld it 100%.
Reply:Weld it in place,
Reply:Thanks for the recent replies, I actually finished up this project.  I pulled it back with the jig, then weld in the support.  It was still pulled in a little after and I have to spread it with the hydraulic jack.  Here is all the pics for it.Here is what I started with.It then went to here.These got made for it.Welded in place and the stock shock mount cut out.New cross member in placeShock mounts on and all finished up
Reply:Can we get pics on the bike?Millermatic 200Hobart Handler 120Victor O/A & Ramco BandsawLincoln 225 ACSnapOn AD HoodMiller XMT304/22AHypertherm Powermax 1650 G3Lincoln Idealarc DC600 w/Extreme 12 VSMiller Digital Elite "Joker"
Reply:so you went from mono shock to dual? looks cool though--------------------------------------------------------------www.becmotors.nlyup, I quit welding.. joined welder anonymous
Reply:Looks excellent to me. I shake to much to get that kind of weld, especially that small. As far as the pull goes, I don't think you had any pull. There are no welds that would pull it together. I think when you pushed it apart to get it into place the tubes bowed a bit. Your brace took care of the bottom of the bow, but the top went back when you let it off. I was thinking that the brace was going to be a bit further up than that and would have taken care of more of it. It makes no difference now tho and I'm sure it will work fine. i also would like to see the bike when finished.
Reply:Originally Posted by Donoharmso you went from mono shock to dual? looks cool though
Reply:Make it work and send more pics, but before you ever start cutting any integral parts like that up always tack up some stiffeners to hold the original shape. Me personally and not being a bunghole I think it's junk now. But try to make it  work. Porta Powers will push more on the ram side and never be true, so you may have to wind up with relief cuts and then weld it back together. I would stare at the engineering end of it before I made a move for a while. Looking forward to seeing the final result tho. I hate being bi-polar it's awsomeMy Heroes Have Always Been Cowboys
Reply:^^^^.  I don't understand, it is working in the last set of pics I posted.  There was also a stiffener in there before it was cut out and the same one was used when the it got welded back together, it was the jig that was used for when the eccentrics got welded in.  I also don't understand the engineering comment.  Fwiw, the frame and swingarm just got checked out by a reputable frame shop for straightness, everything passed.
Reply:Originally Posted by Oxford^^^^.  I don't understand, it is working in the last set of pics I posted.  There was also a stiffener in there before it was cut out and the same one was used when the it got welded back together, it was the jig that was used for when the eccentrics got welded in.  I also don't understand the engineering comment.  Fwiw, the frame and swingarm just got checked out by a reputable frame shop for straightness, everything passed.