GS1100 wheel swap

[isleoman]

High folks,

Great Site! Great bikes! I'm a new poster, long time lurker. Have a 82 1100ez and am thinking about upgrading the wheels and forks. Have researched most of the issues and have a general question about the difference between 18" and 17" wheels.

I see that Bridgestone has the BT-020 sport touring tires in the 18" dia. I don't think I'm going to be running anything stickier than that. If that's the case won't I be better off with 18" GSXR wheels to add to ground clearance if I switch to USD forks. I currently have 5.5" of clearance now and my Yoshimura headers have touched down several times over the 20+ years I've had them (speed bumps). I'm also wondering if it would be easier to stick with a 160 wide tire from that era in the back.

I think my current bias ply is 4.5" in the back. I'm concerned about getting too low in the future and piviting the rear tire in a corner.

I run the BT-020 on my other bike (FZ1) and like them, of course everyone has there own prefernce on tires. The diferrence between radials and bias is very noticible is the that much differnce between 18 and 17? Would like to hear what you think.

I'll post a picture sometime if I can figure it out. The GS is in pretty good shape for 100K miles.

T

[oldschoolGS]

If you go with the 18's the 1988 GSXR 1100 had the best sizes. It is the only year with the 3 spoke wheels in sizes 18x2.75 front and 18x4.5 rear. A 160 is optimum size for the 4.5in rim.


I did a little research when searching for modern wheels for my 83 GS750ED. Clearance was not a problem for me as I replaced the 16in front and 17in rear with 17's from the GSX-F model. If you are going to the expense of doing the swap though I would at least look at the 17's as a possiblity as rubber is much more available in these sizes.

Some of the other guys on this forum have swaped for 17's on similar bikes and can provide more info. Good Luck, Ed
1983 GS750ED

[isleoman]

Ed, thanks for the research on the 88 GSXR. I keep my eye out on ebay and see them from time to time. Of course theres alot more 17" available.

I know there are many more tire brand options in the 17" size but the two brands I'm interested in the Bt-020 or the Pilot roads are both available in the 18" sizes. Who knows if they will continue them in the future.



Thanks again for the input.

T

[isleoman]

Well my plans are changing somewhat. Bought a 96 GSXR 1100 USD Front end whch came with a 17" wheel. These forks measure 30.5" from top of fork tube to center of axle. . I know there are longer forks out there but to find the whole package with triple, six piston brakes, rotors, tire, fender, etc is not as easy. Still thinking about a 18" 4.5" rear.


I'm using this post to see if I figured out how to include a picture. Picture is from last year with 93,000 mi on bike. Motor is original but not stock and has been evolving over the past 20 years.

T

http://photobucket.com/albums/v237/isleoman/?action=view&current=GS1100-side-smooth-7web.jpg&slideshow=paused&interval=3

[isleoman]

Well that didn't work how about this one.

http://img.photobucket.com/albums/v237/isleoman/GS1100-side-smooth-7web.jpg

[isleoman]

Last link worked!

Sorry to ask in the forum but how do you get the images to appear already opened in the post?

T

[Anonymous]

Well that didn't work how about this one.

You forgot the Tags> [img] your url here [/img]

Nice Bike 8)

Got any pics of the new front installed? I am fixing to do it to mine.

[KGB]

Ask Billy Ricks.
He has one of the cleanest 750's you'll see with this conversion.


He's posted his "how to" in here s afew times.
Good read and pretty clear how to do it.

[Anonymous]

I couldn't wait, mines mounted..

Will be starting a post about it soon enough, too busy right now.

Thanks for the headsup KGB 8)

[isleoman]

Busafied,

Thanks for help with posting image. My front isn't mounted yet, I'm changing fork oil and trying to learn how this unit may have been modified (springs / valves).

Anyone happen to know how much oil (or level from top) goes in a 96 GSXR 1100 (KYB) fork?

Did you loose much ground clearance with the 2002 front end?


T

[Anonymous]

I dunno about the frontend oil capacity, sorry.

Mine will need rebuilding before I can ride it, not in a hurry

It appears I have lost approximately 4", that is guessing though, its about a 95 or 96 front end..

I still can slide the tubes down about another 1"-1-1/4"before I reach flush with the top clamp.

In total it was a 30 min swap, one complete frontend to the other.

Peace,
Ron

[Anonymous]

17 or 18

I have converted two of my older bikes from oem to modern 17 tires and wheels and this is my input. Take it for what it is worth. First, the modern 17 inch high performance radial is amazing! But! those of you with 18 or even 19 inch front tires will lose front ride height in a major way and these bikes have ground clearance issues to begin with. Not only are these tires 17's but they are very low profile tires. A modern 17 has a shorter ride height than a 120-80-16! So you want the longest front end you can find to make up some of the diference. The 91 through 93 gsxr750 will blot right on, but the 92ish gsxr1100 fork is a little over an inch longer and comes with much stiffer springs which is a bonus. The 750 fork can give about the same ride height as the 1100 with the use of 954 Honda yokes. The 954 yokes can not be used with the 1100 forks, however because the outer diameter of the upper fork tubes is bigger.

[Anonymous]

17vs18

Those two fork assemblies make the most sense for the GS. The 92 ish gsxr750 with 954 yokes and the complete rolling 92 gsxr 1100. The honda cbr 600 f2 is also a bolt on. these three forks bolt on and come with speedometer drives. The F3 fork also bolts on and has cartridge dampening and full floating rotors, the f2 has neither, but the f3 has no provisions for a speedometer drive. All three of these forks will need stiffer springs with the possible exception of the gsxr1100 fork. I would not recomend cbr929 or 954 forks--- way to short and no provision for spedometer drive. For the same reason I would not recomend the late model GSXR forks. These are wonderful units and the most plentiful fork on Ebay, but they are way to short, way undersprung, no provision for a speedometer drive. The problem with the early gsxr stuff is that it is all 10 or more years old now and it is easier said than done to find a complete early unit. You want the whole thing including yokes, brakes rotors, rims, spacers, speedometer drive, etc. Believe me, you will go crazy hunting down the oddds and ends.

[Anonymous]

17

The rear in many ways presents more of a problem than the front for the gs because it is nearly impossible to get the proper ride height with a low profile 17 in the rear without using much longer shocks and angling them forward. These bikes benefit big time from more ride height even with the eighteeen inch rear so going to a low profile 17 from a high profile 18 is in many ways a step backwards. My 86 GSXR7-11 needed 3 inches of extra ride height to steer decently with the 17's. It steered like a tank with the standard ride height and the 17 and this bike is a much lighter and much more nimble bike than a GS. The problem is that you will need so much swingarm droop that you may have a problem with the chain trying to saw off the front of the swingarm. You can buy some clearance by running a larger rear sprocket, but this shortens your gearing and the shorter rear wheel has already done this. I recomend using the biggest front sprocket you can fit and the biggest rear sprocket that you can justify A good starting point for ride height can be determined by putting the bike on a stand so that the rear tire is off the ground by three inches with the suspension fully topped out. You want the tire touching the ground under similiar conditions. If you can get enough rear ride height the bike will handle much better with this set up, provided some effort is made to get the front forks sprung correctly. If you can not get the rear ride height in this range you will be better of sticking with an 18 inch by 4.5 three spoke wheel from an 88 gsxr1100. It will match the three spoke wheel from the front of the early gsxr's and will give you some extra ride height. thwe problem is that you have no where near the number of tire choices with the 18, but you can easily get a tire that will give you as much traction as the frame can handle. Long story short, 17's front and rear are better if you are willing to put the energy into making them work, but the 18 is less trouble in the back. Ride height is more important than the extra traction of the 17 for sure, especially on these bikes.

[isleoman]

17 vs 18

Maru,

Thanks for the great in depth input, very much appreciated. I have experience with state of the art 17" radials , as I've put about 30K mi. on my FZ1 and other modern bikes. My original question is how much difference is there between 18" radial vs 17" radial of same brand and compound. It would would seem that the 18" radial would at least be significantly better than the 17" bias plys if not quite as good as the 17" radial.

I got tired of watching and waiting on the Holy Grail 92 1100 forks. Katmans 954 idea on the stepped triple is a good one but is there enough room to mount conventional bars on a stepped yoke? By the way my 96 1100 forks measure 50 mm dia. where the top triple clamps and I think thats the same as the 954 top triple but there may be a difference in the spacing of the tube off center.

As stated above the 96 gsxr1100 measure 30.25" from top of fork to center of axel compared to the GS1100e at about 31.5". So I'm initially down 1.25 on just the fork swap. It looks like the 17" wheel that came with the fork will drop me another 1.75 to 2". So I'm down 3.25 and I only had 5.5 to start with under my yosh mid pipe. The triple seems to bolt right up but the wiring loom coming from the enginge has more difficulty getting over the lower triple clamp thanit had with the stock triple.

I was looking at a set of 18" 88 gsxr1100 wheels but price was steep and owner had already tried to mount the 18" tires on a 96 GSXR1100 fork and said that the fender would have to be raised. So I think my next step is to get an 18" rear as you suggest and see how bad things look.

What company in the UK makes the extended fork cap? Do you loose any rigidity with that set up? I know of a company in UK that extends the slider tubes but again very pricey.

Thanks again for the response.

T