Easy GT500 needle Roller Swingarm conversion.

[joolstacho]

I had my Suzuki GS500 swing arm out of the bike, so thought I'd measure it and and compare it to my GT500 SA up.
I found that they are VERY similar and it looks like it would take little adaptation to fit the needle roller SA bearings out of the GS500 into the SA of the GS500.
Both spindles are 14mm dia
Both SA tubes are 34mm OD
Both inner steel bushes are 22mm OD by 14mm ID (but different lengths)
Only difference that I can see is:
Inner Dia of GS500 SA tube/outer dia of Needle roller is 29mm.
Inner Dia of GT500 SA tube/outer dia of Fibre bush is 28.6mm*.
Width of SA Tube is different but that's no problem, just use the GT spindle and shortened inner spacer tube.

So it looks like all would be needed would be
1. Machine the GT SA tube inner dia out from 28.6mm to 29mm - 0.20mm off each wall, not a lot, (Maybe a bit of work with brake hone tool in the SA tube would be enough to fit it)?
2. Cut down a GS500 inner spacer tube to the shorter length required.
*Please note: I have GT bushes that have been slightly shrunk by powder coating heat curing so I can't guarantee that measurement.

The GS Needle roller bearing is TA2230ZC

BTW the GS500 (a very handy air-cooled 4-stroke twin IMHO) has had over 26 years model run, so there are zillions around, parts dead easy to get.
Just a thought lads...
-Jools

[Alan H]

Similar with the G5550 swing arm. It's a direct fit in the GT550 frame.
A bit of a faff with rear master cylinder, but alloy wheels and rear disc an easy fit.

How does the swing arm length compare on the 500s?

[joolstacho]

Yep Alan, and just to clarify for people who might not be aware of the model numbers etc, the GS550 and the GS500 are VERY different animals, The GS550 being the much earlier '77 on twinshock 4 cyl with round tube swing arm, and the GS500 being the later 2 cyl monoshock from '89 on with box-section swing arm.

Swing arm length:
GS500 is 540mm (Centres)
GT500 is 510mm (Centres)
It'd be pretty easy to shorten the GS500 one, all you need is a hacksaw! But there could well be other structural issues that would inhibit the swap.
(Hard to explain, but I can photograph it if anyone needs reference/comparison).

The GS500 SA would NOT fit into the GT500 frame without fairly serious modification.
The width of the GS500 SA tube is 214.5mm as compared with the GT500 which is much narrower at 175.5mm
It could be possible to fit the GS500 SA in the GT500 frame, but as I say it would take more 'serious' adaptation.