Tire fitment on the GSXR 4.5" rear wheel

[Jazzzzz]

I know that when people go with a 150 section tire on the stock wheel, they go with a 150/60 due to the increased profile from pinching the tire onto the rim.  Is a 150/60 still recommended for the 4.5" 89 GSXR wheel, or can I run a 150/70 without adversely affecting handling?  A pal here in town is doing his best to get me to run a 160/60, but I'd rather not have to deal with shimming the cush hub and finding an offset front sprocket.

Why do I ask?  Metz Z6s do not come in a 150/60-17 fitment; I'd rather get the extra tread life out of them than bump up to the M1s, which do have a 150/60-17.

[gsJack]

It is a very common practice to run the 150/60 on the GS because it's the only size that will resonably fit on the 3.5" rim in sport/supersport rubber like the M1/M3 or Pilot Sports/Powers, etc; however the 150/70 is actually a better fit on our 3.5" rim.  It is approved by half the tire mfgs for the 150/70 but is not approved for the 150/60 by any of them on our rim.

I'm currently running a 150/70 Metz Lasertec on my 02 GS and it just fits without any mods and with just enough clearance to the brake torque rod.   For a 150/70 sport touring radial, I'd try the Pirelli Diablo Strada rather than the Z6 since it's about 4mm narrower.  The Strada came out after Pirelli bought Metzeler and Metzeler started making the Pirelli motorcycle tires.   The Z6 and Strada are nearly identical in appearance and performance and both are made in Germany now.

There are people here running the Z6 and the Avon AV46 in the 150/70 size.  I've run the Z2 in the 130/80 size and the AV46 in the 140/80 size on my GSs.   My handling with the 150/70 Lasertec is great, as good as it was with the sport touring radials.  I like them but don't expect the rear to last like the ST radials did, I'm thinking of trying the 150/70 Strada next with the Lasertec front.   

[gsJack]

Forgot to answer to your question, the 150/70 will fit the 4.5" wheel.  The preferred fit for the 150/70 is a 4" wheel with 3.5-4.5" wheels being an approved fit by Metz or Pirelli.