ZR550 or ZR750 Swingarm on Z650 (KZ650) - How To - Hopefully!

I've been battling for a while, a good sound way to get my Zephyr 550 Swingarm to fit my Z650, because of the spindle diameter differences.

I've thought about taking the diameter of the hole in the frame out through various methods, but the accuracy of the location of the hole, concerned me, (a little bit out at the swingarm pivot end, could spell a country mile out at the rear wheel pivot!)

So... lots of research into the bearings and so on led to...

The outer races of the bearing (the actual rollers) are the same size as several Suzuki models, GS, GSX, GSXR, 750s 1100s, SV650 and probably others too.

The dimensions of the roller bearings (the outer swingarm race) are 25x33x30 (25mm id, 33mm od, 30mm wide)on the Zephyr arm, this equates to 92046-1035 OEM Kawasaki # (Zephyr 550 etc) and also equates to 09263-25024 OEM Suzuki #.

But the important thing is that many of these Suzuki's take a 16mm spindle, which will enable the use of the original KZ650 spindle, with the Zephyr Swingarm.

Unlike the Zephyr set up, which has one sleeve, which acts as the inner race for both left and right roller, the Suzuki set up employs two sleeves, one for each roller, and a spacer sleeve that fits between the two.

The Suzuki inner races with 16mm bore are Suzuki OEM # 61251-49000 which are 16x25x35, which will of course take the standard KZ650 spindle.

Ron Ayers list the inner races as fitting GSX1100F Katana 88-93, but elsewhere I've found other models with this part number of inner race, GSX750S, RF400, GSF400 Bandit, SV400, and more than likely many others (the RF400 is chassis wise identical to the RF600). I'll be using RF400 inner races, because I already have an RF swingarm, complete with bearings.

The next stage is to make the overall length of the assembly correct. The length of the Zephyr inner race is 230mm (remember this is a one piece affair) with an OD of 25mm, and an ID of 17.1mm.

What I will be doing is cutting down the standard Zephyr inner race (sleeve) and using it as a spacer between the two Suzuki races, which are 35mm each, I'll be turning it so that the end is square down to 160mm, then this will be perfect as a spacing sleeve.

Its not possible to use the standard Suzuki sleeve, as it only measures 151mm, which would make the whole assembly 9mm short. The clearance on the bore will make this no problem.

So there you have it, for me it should end up a free job, provided everything goes to plan, Ron Ayers list them at $13.69, not sure if that is each or a pair, but either way it is a better option than drilling your frame or having an entire inner race made up with a 16mm bore.

At the moment this is all theoretical - but I have worked it all out and can see no problems, but within a few days, I should have carried out the mod, and will be able to report back.

Hope this is of use to some of you guys out there, can this be made as a sort of sticky, or in a how to guide?

Made a mistake, the RF 400 bearings and so on don't fit, but the GSX750S & GSX1100S will - the part number listed above is still correct.
Cheers

Also, GS1000, GSX1100X, GSX1100T, GS1100E & GSX-R1100 (GU74 86-88) bearings use the same inner sleeve race.

If I'm not mistaken, onkelb put a similar arm on his 650.
He may be of some assistance to you.

Yes I know, there's a few that have done it on here, but most have done it by drilling out the frame to take the 17mm spindle, whereas my method should use the standard 16mm spindle.

Well, the next stage is done, I've bought the Suzuki inner sleeves from my local stealership, and trialled them in the swingarm, and they are a perfect fit, trialled the spindle in aswell and everything is fine. All thats left is to machine down the old inner race/sleeve, from 230mm to 160mm. I'll keep you posted!

Can you post some pics... sorry its a bit late and I cant visualize.
Thanks!

Right then, just got the sleeve back - its been machined down to the right size (160mm) now I'm ready to refit. Had to use a tipped cutting tool, because the sleeve was hardened - as bearing surfaces usually are! Here's the first bit:

Right then, just got the sleeve back - its been machined down to the right size (160mm) now I'm ready to refit. Had to use a tipped cutting tool, because the sleeve was hardened - as bearing surfaces usually are! Here's the first bit:

next bit (exploded view)

new assy - right I'm off to trial fit now!

How did this all work out? I'm looking to adapt a new swingarm and this seems promising.