Topic: Modified Rear Frame Triangle (who has done it)

[SEBNN]

I am thinking of moving the lower bar in my rear triangle area of my frame up about 4 inches to make room to mount my rearsets directly to the vertical tube that holds the rear engine mounts.  My initial thought is to just cut the tube part way up and bend it over to the vertical tube and reweld.  Has anyone done something like this?  If so, any pictures and thoughts or advice?  Anything that you would do differently?  Just wanted to see where people have gone with this.

[cafe75-550]

Haven't done that, but I have done framework before. I would suggest bracing the frame prior to removing anything to keep the frame from distorting, you can tack weld in a brace or two and remove them when your modification is complete...

[SEBNN]

That is a good idea.  I was planning on adding a few stiffeners to the frame, I may tack some of those in prior to starting as additional braces if I go this way.  I've seen the way some of the thicker metal at work distorts when the welders put it all together so I imagine that this would be about as bad.

[babyfood1217]

don't know if it is quite what you are thinking about, but here is my little project...

http://forums.sohc4.net/index.php?topic=23238.0

Still on going.  Frame modding is done, now its' tank/seat construction and then the little things.

[SEBNN]

Not quite like that.  Mine was more on moving the attachment point of the lower bar from behind the engine mounts to up above them a little.  Then I was going to mount the rear sets where it had connected.  Thinking of using some smaller diameter tubing as an additional crossbar and support.

[flipprboi]

Is it something like this?

[SEBNN]

Is it something like this?

Yeah, thats more like it.  I wasn't planning on moving the rear shock mounts, more of bending the tube so that it connects between the two rear engine mounts (about 2-3" lower than in the picture).  The frame looks really good, I like how things have been placed and the small design upgrades.  Is this a mod that Benji's does?

[KB02]

My initial thought is to just cut the tube part way up and bend it over to the vertical tube and reweld.

The frame in the picture looks good, but your above quote worries me a bit. Don't actually "Bend" the tube. Once you bend a tube it starts to loose it's strength. I'm sure you knew that and weren't going to actually bend it, but I felt it should be said. 

[hopterfixer]

Is it something like this?

Yeah, thats more like it.  I wasn't planning on moving the rear shock mounts, more of bending the tube so that it connects between the two rear engine mounts (about 2-3" lower than in the picture).  The frame looks really good, I like how things have been placed and the small design upgrades.  Is this a mod that Benji's does?

I believe that was Benjie who posted.

[FunJimmy]

Rather than mod the frame to fit the rearsets, why not make the rearsets to fit the frame?

[SEBNN]

My initial thought is to just cut the tube part way up and bend it over to the vertical tube and reweld.

The frame in the picture looks good, but your above quote worries me a bit. Don't actually "Bend[/b]" the tube. Once you bend a tube it starts to loose it's strength. I'm sure you knew that and weren't going to actually bend it, but I felt it should be said. 

Bend is so ambiguous, I was planning on cutting out all but a small strip and then bending that and re-welding.  My idea was by cutting out a section and bending a small portion that I would keep good alignment and that it would help with placement.

I want to move the frame up a little, I have tried making a mount for the rear-sets, but just can't get it to look right as I would either be placing the rearsets on the outside of the frame, rather than flush with it, or using a large mount to try and align it correctly.  Either way I looked at it and worried over it I couldn't get it to look right.  So, since cutting and re-welding is an option, I can move the cross member and get the look that I would like.

I will need to gusset it somewhat and I was going to add a smaller diameter tube as an additional frame support.  Also, I am looking at a lower battery mount if I can.  But not sure on that yet as I would prefer to have it out of site as much as anything.

[FunJimmy]

SEBNN

What bike are you working on?
Can you post a picture of the frame and the rearsets that you are using?FJ

[SEBNN]

SEBNN

What bike are you working on?
Can you post a picture of the frame and the rearsets that you are using?FJ

I am working on a 77 cb550.  The rearsets in the picture are the ones I will be using, they are off of a 2005 (ish) GSXR 750.  The tabs they are mounted to are my first attempt.  I was going to cut some new thinner ones out at work, saw another thread and someone elses mounting idea, which I looked at for a while, and then I thought that I could really improve it if I Cut and rewelded the rear triangle on my frame.  I am mainly worried about the effect that it would have on the shocks as I think the main purpose of these tubes is to support the suspension (and rider) mounts for the rear shocks.  Anyways, the first one is just the frame and one rearset, the second is a crude ms paint work showing my intended cut and and angle change.  I was only able to put in one rear set, and I was unable to change its mounting angle, but it gives you an idea of what I am thinking of doing.

Edited to add:  After looking at it this morning, man that is an ugly job I did with ms paint.  But the idea is still there.

[SEBNN]

Well, cutting and welding started, then to grind the welds down a little and to add some gussets.  Anyways, looks like it all came out straight and lined up.  Rearset mounts are on and lined up.  I will post pictures once the grinding is done and rearsets mounted up.  Next to grind off rear brake stop arm mount from the swingarm and the chain guard mounts.  Oh the fun.

added:  Here is a picture with no gussets and a quick rustoleum paint job so I could get an idea of how it will look finished.  Swingarm is clean and hanging to dry as I painted over the now bare metal to prevent rust.  Does anyone know if the gussets would be that useful now?  Just curious if I need to go ahead and add them.

[KB02]

Does anyone know if the gussets would be that useful now?  Just curious if I need to go ahead and add them.

I say add them.