GPZ550 or KZ550 Swing Arm/ Rear End Swap

Has anyone swapped a more modern swingarm in? All my searches have led to some of the bigger bikes. I'd like to get a VFR or GSXR swing arm in there if possible but really anything that will allow me to run a wider rear tire would be perfect. With the stock 84 gpz550 swingarm, the 130/80/18 seems to be the max.

I know i can probably make anything fit in there but before I start ordering random expensive parts, it'd be nice to see if there's anything documented.

Here's a pic of the bike:

Hello jfarhanbod
Here some charts for swing arms,shocks and forks.





Translation

Breite Schwinge Vo. = width swing arm to frame (pivot diameter)
Breite Schwinge Hi. = width swing arm for rear wheel + all components, sprocket holder/rear brake (pivot diameter)

Michael

From previous research width between the swingarm pivots for the KZ400 is 8.5 inches. Width for the larger KZ bikes ( KZ650 and KZ750 twin confirmed, I assume others are the same, not sure about KZ550 ) is 9" or approx 228.5mm. The GSXR 750 should be a good fit. It looks like some of the VFRs will work too. I'd also look for R6 swingarm specs too.

I fitted a custom 650 swingarm into a 550 twinshock, from memory there was several mm difference which was fixed by machining down the bearing caps. IIRC also about an inch longer.

Going any bigger than 130 on that rim won't work, really you want a complete swingarm, wheel, caliper assembly, zrx1100 would be a popular choice.

I just measured my bare 550 81 d1 frame, getting 225mm for the swingarm pivot. You don't want to go too long on the length, the 550 twinshocks have a short wheelbase which makes them agile.

another consideration is your sprocket offset, there are various ways of fixing this...

Anyone have any specs on the ZR7 swingarm? All I can find is the pivot axle diameter which would be a straight swap, but i cant find anything on the pivot width or the swingarm length.