Rear tire : How wide is enough?

[katanarama]

When it comes to updating a twin shock GS1100's wheels with later Suzuki offerings, how big is big enough? A 5.5" rim with 170 or 180-width tires look to be the most common conversion. Is this required? What real difference, besides perhaps more choice of tires, would fitting a 170 have over a 160?

[joe.d]

Sometimes bigger isnt better, running a large tire in a old bike wont make it handle any better, it may even make it handle worse. things you have to consider, chain run... allso running a wider wheel means you have to run a offset front spocket, which will put stress on the counter shaft...
getting a older GSXR 4 inch wide 17 wheel was the answer I came up with for the rear of my EFE, I used a Oil cooled Plastic jelly mould Katana rear wheel and had to exchange the bearings in the wheel from the katana to the EFE size, which the ID is larger, to get this to work I allso had to go to a 530 Chain conversion, I could get a 160 in my rear end but that was maxed out,
the rear conversion then was well ballanced with the USD GIXER 1100 front end.

[katanarama]

Did you use a 4.5" rear from a late 80's GSXR750 perchance?
Which brand of tire and model are you running Joe & what kind of life are you getting from them?

[outofcontrol]

almost all modern sportbikes use 160-190 x 17" rear tires. You definitely have to match the tire to the rim size, and going with the widest tire possible will not necessarily net you the best performance. Have you ever ridden a chopper with a 250 rear? Handling is a joke. Also, the 180+ tires are needed to help put down 120 hp on a 600 or 160+ hp on a 1L bike. I only put a 190 on my 1100 because it was given to me, and I don’t really care about performance. This is my street bike, and I’ll never ride it to 50% of its potential anyway. Even with a 160, you can get the best tires out there. Don’t be fooled to think you should buy a race tire for the best performance possible. A race tire doesn’t get sticky until it’s about 160*F, and you’ll never get that hot on the street. A good street tire will be super sticky at street temps, and ultimately a safer tire. I use the race take-offs because they are free for me, and I don’t care about ultimate traction. I also kind of like the looks of the wide 190. Even though it sucks for traction most of the time. The 1100 has some drag racing history, and I think a massive rear is appropriate.

Just some ideas.

joe.d, your bike is awesome. well done.

-KM

[joe.d]

The rear wheel is off of a KATANA ( TEAPOT )GSF750, the wheel bearings had to be changed so it would fit the EF wheel spindle, the Katana brake disc was used but it was about half inch smaller, and so far hasnt caused any problems with the rear brake, I use bridgestones and havnt got through a set yet, 160 X 17 rear- 120 X 17 front.

[RJ]

I recently did the GSXR rear wheel/front end swap on my '82 1100E. The rear wheel is a 5.5" wide 17 incher off of a '93 GSXR 750 with a 170 series tire. The wheel bearings are identical to the GS's so I was able to use the older axle assembly to mount the thing into the GS swingarm. The tricky parts were offsetting the front sprocket and reconfiguring the rear caliper.
I used the GS hub and sprocket (already converted to 530 series chain prior to the swap) which again fits right into the GSXR wheel. This allowed me to simply use large hardware store washers to shim the front sprocket in order to align the chain properly. No fancy offset sprocket required. I did have to grind the inside of the frame a little to clear the chain.
For the rear caliper I used a Hayabusa unit clamping onto an RF900 rotor. I had to have a torque rod mount welded onto the bottom of the swingarm in order to use the caliper. The same setup could have been accomplished with GSXR parts, but I used what was available on eBay at the time. $15 for the rotor, $9 for the caliper, $6 for the rod. It all works great.
I'm certainly not the first or smartest person to do this mod by any means, but it wasn't as complex as some other approaches I have seen. If you go with the wide rear wheel/tire thing remember that you are now using a radial tire which needs to be matched with a radial tire up front, so it's an all or nothing proposition.

[joe.d]

theres actually a little more room in the twin shock GS's than the EFE thats why I went with the KATANA

[katanarama]

That is a really nice looking EFE Joe.

For those here that made the wider rim conversion, any experience with the rear tire touching the frame rails when rear suspension is super compressed?

[mlaalm]

I've already switched out my front end. Now I'm replacing my bias 3.5 rear with an 18 inch Late 80's 4.5 inch GSXR1100 rear rim with 160/60 radial rubber to match my front radial. Wanted the extra half inch ground clearance in the rear so I had to wait it out for the 18 inch three spoke to pop up on ebay.

Before:

[mlaalm]

Thought hard on mounting a GSXR swingarm and going the 180/55 series rubber. Would like to raise the rear end a tad but don't want the whole 'rear shock mounting' project right now. The 18 inch rim with 60 series rubber not too far from my current 17 inch rim with 90 series rubber. I can live with the differene. Good Luck with your project - Mike

[RifRafRacing]

I have front and rear wheels from an 86 GSXR 1100 with nice rubber(18x4-18x2.75)comes with rear hub,fair 530 aluminum sprocket,nice front rotors.$180 for all plus shipping.Im in Massachusetts. thanks, Steve RifRafRacing@comcast.net

[GS500xxx]

I've already switched out my front end. Now I'm replacing my bias 3.5 rear with an 18 inch Late 80's 4.5 inch GSXR1100 rear rim with 160/60 radial rubber to match my front radial. Wanted the extra half inch ground clearance in the rear so I had to wait it out for the 18 inch three spoke to pop up on ebay.

Before:

are they GIXXER clocks?

[katanarama]

I would say so, EF clocks are square.

[Cassius086]

I have front and rear wheels from an 86 GSXR 1100 with nice rubber(18x4.5-18x3)comes with rear hub,fair 530 aluminum sprocket,nice front rotors.$180 for all plus shipping.Im in Massachusetts. thanks, Steve RifRafRacing@comcast.net

Stock 1100 rears were 4.0" til 88, right? I have the '87 three spoke and the rear is 4.0 even...running 160/60R18 Michelin Pilot Roads....

[mlaalm]

GS500xxx
Junior Member

Yes they are from a 91GSXR750. If you take your time its not too hard to figure out the wiring for the indicators and tach. They mount directly under the upper triple tree since the trees are from the same year models (91-94).

My rear wheel came in the other day. 18inch 88GSXR1100 4.5 with 170/60 18 rubber on it. You can run 170 series on a stock GS1150 swingarm if your willing to fab a new (thinner) rear caliper mount and possibly another brake rod. My biggest problem with going with the wider low profile rubber is seat height / ground clearance. I'm going to go ahead a bite-the-bullet and have a GSXR or BANDIT swingarm mounted with the help of a mechanic friend. Its not really for the wider 5.5 inch rim I'll be able to run but more so for the dogbones I'll be able to adjust. Going too wide without adding seat height on these older bikes takes away too much handling.