Longer swingarm on a 450?

[Guest]

Hello to all! (My first post here)

I know there are many threads about swingarm swaps but I couldn't find any done on a 450.

My project is a badly neglected -82 GS450, which I'm planning to build in to something in the bobber direction. For appearance's sake I would like a longer swingarm. There are cases of putting a GS1100E swingarm to GS750's and 550's, but will it fit a 450? Any other approaches to the "problem"?

Thanks in advance!

[bwringer]

I don't have sample bikes right here in front of me, but IIRC, swingarms from the 4-cylinder bikes are MUCH wider than on the twins.

Not sure what a suitable replacement might be, or whether a GS500 swingarm would do any good (you'd have to deal with shock mounts somehow), but you might be best off looking at extending the existing swingarm.

Time to get out a tape measure and calipers and visit a junkyard.

[tekkie]

I don't have sample bikes right here in front of me, but IIRC, swingarms from the 4-cylinder bikes are MUCH wider than on the twins.

Not sure what a suitable replacement might be, or whether a GS500 swingarm would do any good (you'd have to deal with shock mounts somehow), but you might be best off looking at extending the existing swingarm.

Time to get out a tape measure and calipers and visit a junkyard.

Makes sense. Thanks! Back to the drawing board, then.

[Big Rich]

I don't have a GS450 swingarm laying around that I could measure, but I do have a GS500 swinger hanging up in the garage. I can measure the pivot width and post back.

[tekkie]

I don't have a GS450 swingarm laying around that I could measure, but I do have a GS500 swinger hanging up in the garage. I can measure the pivot width and post back.

Sure, thanks! That would be helpful. There are lots of GS500 parts available so it would be great if that fitted. While you're at it, could you also measure the length of the swinger? If it's the same length as a 450 one, then the swap would be a meaningless excercise

[tkent02]

It would probably be a lot more rigid than the old one.

[hardline_42]

The GS450 swinger is something like 8.25" wide at the pivot and 18" long to the center of the axle adjustment. The GS500 should be about 8.425" wide at the pivot and 21.5" to the axle. The extra length is all in the section between the pivot and the monoshock mount. Here's an idea of what it looks like on a GS450 S/E model (converted to monoshock and modern wheels):



It's a WERA racebike, not a bobber, but should give you an idea of the length.

[Big Rich]

Good grief, that's a good looking bike.....

Tekkie, I didn't get a chance to measure that pivot width today. But I'll confirm Hardline's measurements tomorrow. I do know that the 500 swinger is definitely longer (as was previously stated).

[hardline_42]

Good grief, that's a good looking bike.....

Rich, that bike is Rich Gravers 2008 WERA race bike:


It's got a GSXR front end and a GS500 rear and an engine pushing 600cc. I'm planning something similar with an SV650 front end so I've been researching and accumulating info. But it'd be nice if you could confirm the dims on the 500 swinger.

[tekkie]

Didn't realise before now that GS500 has a monoshock... I'm planning to keep the oldschool shock layout so I would have to fabricate mountings for them. Extending the old swinger is starting to look like the way to go.

[Big Rich]

Well, the GS500 is steel (not aluminum) so it would be pretty easy to add shock mounts. Just food for thought......

[tekkie]

Well, the GS500 is steel (not aluminum) so it would be pretty easy to add shock mounts. Just food for thought......

Good to know, I thought it was aluminium by the looks of it.

[Big Rich]

Just checked: over the dust caps, the pivot point on the GS500 swinger is 8.626" wide. Without the dust caps, it is 8.375" wide. On the plus side: there is enough material on the sides that you could cut some of it off to fit the GS450 frame.

[tekkie]

Just checked: over the dust caps, the pivot point on the GS500 swinger is 8.626" wide. Without the dust caps, it is 8.375" wide. On the plus side: there is enough material on the sides that you could cut some of it off to fit the GS450 frame.

Thanks again. I'll have to see if I can find a decommissioned GS500 to purchase for parts. I wish to cannibalize some parts for the engine, too.