I NEED THE TRUTH(fork swaps)

[LagunasOnlyGS]

I have been misguided and misdirected by many people and i cant take it!

So once again i post! I want to swap my forks and swingarm off my 1982 GS1100E to a newer, inverted, shorter, lighterweight set up! Off a 90's gixxer perhaps, i heard they were the most compatable!

I can not weld or cut metal, i have not the tools! BUT i can change out bearings, make spacers, etc. etc. extensive fab is possible as long as it does not involve metal working like the kind noted above!

ANY help and advise would be greatly appreciated as always!!!

AND any owners in the orange county california area PLEASE private message me! [-o<

I'm tired of being the ONLY GS at bike nights! It's lonely!

PIECE and LOVE 8-)

[RJ]

I have an '82 1100E with a GSXR front end and rear wheel. It wasn't all that hard to do.
First off, look for a front end from '90-'95 750 or 1100. The 1100 forks are a little fatter than the 750 so you need to get the triple clamp assembly from the same bike you get the forks from. Try to get the entire assembly if you can as it is a lot easier than cobbling together bits and pieces from different bikes (like I did), although not impossible. The steering head bearings from that era GSXR and the GS are identical so it's a direct bolt-in, However I would recommend replacing the bearings while everything is apart.
You could probably get away with using the GS rear wheel with the GSXR front end, but it looks goofy and won't take full advantage of the suspension upgrade up front. Wheels are interchangeable between models with that era of GSXR. I used a '92 750 wheel. It is 5.5" wide with a 170 series tire on it. That's about as wide as you can go using the GS swingarm. You will need to swap to a 530 chain to make it work. You will also need to grind about 1/8" or so from the inside of the frame where the footpegs bolt up. The frame is very thick in this area so there is no safety issue to worry about. Swap the GS sprocket/hub onto the new wheel. The wheel will now fit where the old one did using the GS spacers in the same configuration. You will need to go to a GSXR rear caliper,caliper hanger, and truss rod because the rotor is different from the GS. This is the only true fabrication/weld issue in the whole deal. The truss rod is mounted underneath the swingarm on GSXR's for that style of caliper. I mounted the wheel in the swingarm (wheel bearings are identical between GS and GSXR) with the caliper and truss rod in place, removed swingarm and all, took the whole mess to a welder. I showed him right where I wanted the new truss rod mount, he fabricated and welded the mount for $65. Now you bolt the whole assembly back into the bike. The GS master cylinder should work with the new caliper. I changed mine to a Hayabusa unit 'cause I got it cheaper than a rebuild kit for the old one, so I'm not 100% sure about the compatability issue.
You will need to shim out the front sprocket to line it up with the rear. Some guys on this site advocate using and offset sprocket. I found that by using large hardware store washers I was able to shim out the sprocket to the right spot and still have full contact with the splines on the countershaft.
The only other thing to look at is the speedometer. Because the wheel/tire size is different the speedo is now going to be inaccurate. You would need to swap to a speedo from a bike using a 17" front wheel. I used an instrument cluster from a 1990 Bandit 400. Works great.
There are probably other ways to go about doing this swap, this was my approach and it works well. All my parts were scored on eBay in a few weeks. I was amazed at how much better the bike handles and stops. Even from a cosmetic standpoint the bike just looks meaner. You do lose some ground clearance so watch that header!
Good luck, it's worth the effort.

[fat_sac]

I have an '82 1100E with a GSXR front end and rear wheel. It wasn't all that hard to do.
First off, look for a front end from '90-'95 750 or 1100. The 1100 forks are a little fatter than the 750 so you need to get the triple clamp assembly from the same bike you get the forks from. Try to get the entire assembly if you can as it is a lot easier than cobbling together bits and pieces from different bikes (like I did), although not impossible. The steering head bearings from that era GSXR and the GS are identical so it's a direct bolt-in, However I would recommend replacing the bearings while everything is apart.
You could probably get away with using the GS rear wheel with the GSXR front end, but it looks goofy and won't take full advantage of the suspension upgrade up front. Wheels are interchangeable between models with that era of GSXR. I used a '92 750 wheel. It is 5.5" wide with a 170 series tire on it. That's about as wide as you can go using the GS swingarm. You will need to swap to a 530 chain to make it work. You will also need to grind about 1/8" or so from the inside of the frame where the footpegs bolt up. The frame is very thick in this area so there is no safety issue to worry about. Swap the GS sprocket/hub onto the new wheel. The wheel will now fit where the old one did using the GS spacers in the same configuration. You will need to go to a GSXR rear caliper,caliper hanger, and truss rod because the rotor is different from the GS. This is the only true fabrication/weld issue in the whole deal. The truss rod is mounted underneath the swingarm on GSXR's for that style of caliper. I mounted the wheel in the swingarm (wheel bearings are identical between GS and GSXR) with the caliper and truss rod in place, removed swingarm and all, took the whole mess to a welder. I showed him right where I wanted the new truss rod mount, he fabricated and welded the mount for $65. Now you bolt the whole assembly back into the bike. The GS master cylinder should work with the new caliper. I changed mine to a Hayabusa unit 'cause I got it cheaper than a rebuild kit for the old one, so I'm not 100% sure about the compatability issue.
You will need to shim out the front sprocket to line it up with the rear. Some guys on this site advocate using and offset sprocket. I found that by using large hardware store washers I was able to shim out the sprocket to the right spot and still have full contact with the splines on the countershaft.
The only other thing to look at is the speedometer. Because the wheel/tire size is different the speedo is now going to be inaccurate. You would need to swap to a speedo from a bike using a 17" front wheel. I used an instrument cluster from a 1990 Bandit 400. Works great.
There are probably other ways to go about doing this swap, this was my approach and it works well. All my parts were scored on eBay in a few weeks. I was amazed at how much better the bike handles and stops. Even from a cosmetic standpoint the bike just looks meaner. You do lose some ground clearance so watch that header!
Good luck, it's worth the effort.

Can I get pix of this? I'm in the middle of a similar project. I'm using an F2 as a donor though.

[hungryman]

Also, keep in mind some GSXR forks are longer than others. I don't have the years in front of me, but that data is here - somewhere. I think the longest are slightly over 30" - off an 1100 - 93? They have 52 mm uppers.

If you get 50 mm uppers then you can gain a bit more ground clearance using Honda 954 triples. Be carefull though, make sure you get the ones with the tapered bearings, not the roller.

Once you swap the forks you will need to do something about the rear, since running radial up front and bias in back is dangerous. There are quite a few options on that. I picked the most difficult I think - conversion to mono.

[RJ]

F2 forks are going to be too short and you will lose far too much ground clearance. It's also going to make for twitchy steering geometry. From top to bottom my forks are 31 1/2" tall. I did try to upload some photos, hopefully I did it right.

[RJ]

Oh well, it seems the file size of my photos is too large. I've got the camera on the lowest setting possible but it's still too big. Maybe the website needs to be bigger.

[fat_sac]

That's cool, sendem to greenmansoup at gmail dot com. I'll post em for you. I didn't know the f2 forks were that short. Maybe I'll just stick with gx'r stuff. Do you think an f2 wheel will fit on the gx'r forks? I could even still use my dual caliper GS forks if I can get teh wheel to fit. I can fab an adapter for the calipers.

[marcovandevelde]

Excellent write up RJ! If anyone doesn't understand how to swap now, they need to steer away from the whole thing.

One comment to clear things a bit though:

Quote:
The only other thing to look at is the speedometer. Because the wheel/tire size is different the speedo is now going to be inaccurate. You would need to swap to a speedo from a bike using a 17" front wheel. I used an instrument cluster from a 1990 Bandit 400. Works great.


If you use the speedo drive that comes with the new wheel, there will be no problem matching it to the orig. gauges, or any other analogue Suzuki gauges. In fact, Suzuki and Yamaha use the same ratios on their bikes so as long as you have the drive to go with the wheel you're fine with either brand gauges. Kawasaki's are different and can't be matched with another brand like that!

Greetings, Marco.

[LagunasOnlyGS]

But

Speedo and guages i'm not worried about. I was going to swap them COMPLETELY out anyway. Checking out Dakota Digital stuff but it is sooo $$$.

A friend of mine is going to make me a billet aluminum guage cluster/bracket and also a new rear brake torque rod that is offset to clear the tire!

I THINK he has a welder as well so we shall see!

[RJ]

Hey Marco,
Thanks for the positive feedback. I'm not so sure about your assessment on the speedo issue though. While it is true that the speedo drives are interchangeable from a mechanical standpoint, the rpms that the front wheel makes will be different from one size wheel to another over the same distance. The outside of the larger wheel/tire combo has more linear distance to cover in order to make one revolution than the smaller one. In other words, if you had a wheel that was one mile in diameter, it would take one revolution of the wheel to cover a mile. Anything smaller would take more revolutions to cover the same distance. The speedometer essentially counts the number of revolutions the front wheel makes in a given amount of time. If those numbers of revolutions change the speedo is no longer accurate. It is the combination of the wheel size and the internal gears of the speedo that give you your dial reading.
This can be seen when you change from factory issue wheel/tire combos on trucks whith much larger combos for off-road use. They have programs that recalibrate the speedo sensor in the transmission for just such a change on newer vehicles.
I will say that I have not acutally compared the two speedos so, as my wife would testify, I may be wrong. However Paul Khanert, whose GS1000 was bike of the month in June 2005 I believe, did the same swap on his bike and told me that his speedo was off as a result.
Even if I am wrong, the Bandit gauges look much cleaner than the '80's monstrosity that came with the bike, although you do lose the fuel and oil temp gauges. If I can get my camera setting low enough to upload some photos I'll be able to show you guys. Bandit 600 gauges are very similar, and I think 1st generation Bandit 1200 gauges have the mechanical speedo as well.

[Dink]

A lot of mid 90's on bikes do NOT drive the speedo off the front wheel at all, another issue to keep in mind.
They drive off the countershaft in most cases.

Dink

[RJ]

Correction on my previous post. I should have said "circumference", not "diameter" with the one mile wheel example. Need to re-visit geometry book.

[Macmatic]

Hey Marco,
Thanks for the positive feedback. I'm not so sure about your assessment on the speedo issue though. While it is true that the speedo drives are interchangeable from a mechanical standpoint, the rpms that the front wheel makes will be different from one size wheel to another over the same distance. The outside of the larger wheel/tire combo has more linear distance to cover in order to make one revolution than the smaller one. In other words, if you had a wheel that was one mile in diameter, it would take one revolution of the wheel to cover a mile. Anything smaller would take more revolutions to cover the same distance. The speedometer essentially counts the number of revolutions the front wheel makes in a given amount of time. If those numbers of revolutions change the speedo is no longer accurate. It is the combination of the wheel size and the internal gears of the speedo that give you your dial reading.
This can be seen when you change from factory issue wheel/tire combos on trucks whith much larger combos for off-road use. They have programs that recalibrate the speedo sensor in the transmission for just such a change on newer vehicles.
I will say that I have not acutally compared the two speedos so, as my wife would testify, I may be wrong. However Paul Khanert, whose GS1000 was bike of the month in June 2005 I believe, did the same swap on his bike and told me that his speedo was off as a result.
Even if I am wrong, the Bandit gauges look much cleaner than the '80's monstrosity that came with the bike, although you do lose the fuel and oil temp gauges. If I can get my camera setting low enough to upload some photos I'll be able to show you guys. Bandit 600 gauges are very similar, and I think 1st generation Bandit 1200 gauges have the mechanical speedo as well.

RJ,

I think what Marco is saying is that bikes with different size wheels come with speedo senders that have the correct ratio for that size so that the speedo cable is driven at the correct speed for the speedo head as long as the correct sender for the wheel size is used.

I'm not sure if he's correct on that but I'm pretty sure thats what he means. I relubed my sender last summer and had some questions about ratio. People seemed to think the senders were all the same and the head units had different ratios for varyign wheel sizes.

On the camera can you chance images SIZE as well as QUALITY? try saving at something like 800x600 rather than 1200x800. But no matter what the quality there are dozens of apps out there you can get for free that will let you resize an image. Its likely that your computer already has one on it from the factory.

/\/\ac

[Billy Ricks]

I do know that when I went from my stock 16" wheel to the 17" GSXR wheel my speedo was off by about 10%. It was all the excuse I needed to adapt GSXR gauges.

[1quik6]

Wheels are interchangeable between models with that era of GSXR. I used a '92 750 wheel. It is 5.5" wide with a 170 series tire on it. That's about as wide as you can go using the GS swingarm. You will need to swap to a 530 chain to make it work. You will also need to grind about 1/8" or so from the inside of the frame where the footpegs bolt up. The frame is very thick in this area so there is no safety issue to worry about. Swap the GS sprocket/hub onto the new wheel. The wheel will now fit where the old one did using the GS spacers in the same configuration. You will need to go to a GSXR rear caliper,caliper hanger, and truss rod because the rotor is different from the GS. This is the only true fabrication/weld issue in the whole deal. The truss rod is mounted underneath the swingarm on GSXR's for that style of caliper. I mounted the wheel in the swingarm (wheel bearings are identical between GS and GSXR) with the caliper and truss rod in place, removed swingarm and all, took the whole mess to a welder. I showed him right where I wanted the new truss rod mount, he fabricated and welded the mount for $65. Now you bolt the whole assembly back into the bike.

RJ, I am a little confused on what swingarm you are using. It sounds like you are talking about the stock swingarm, but I don't understand where you are grinding and why?
Also if you could email me pics of your bike, I would appreciate it.
1quik6 @ everestkc.net