GSXR Conversion/Swingarm Questions

[Sc0ttzi]

I just bought another 79 GS1000 and I was planning on doing something similar to what 80GS1000 did with his. Although, I would like to keep a dual sided shock swingarm on it to keep more of the old look, and because I would like to be able to mount dual Ohlins su143's. Does anyone know of a good swingarm that would fit any of the later GSXR wheels, be something of a straight bolt on to the frame, and would be a decent doner for having shock mounts welded on or has shock mounts already? I know I've seen someone with a Bandit swingarm on an 1100, I'm just not sure how well it would work for the older 1000, or how long it would be comparable to the original swingarms length. Also a question about the front end. If I were to purchase any complete 00-08 GSXR1000 front end, would it just bolt on without any modification (other than being resprung and having steering stops welded on the frame)?

[jwhelan65]

Conversion

Check with Rob Wilton (katman) he is an excellent source. His email is rob@robwilton.com. Check out his website for some details under Tech at robwilton.com. He walked me through my rear conversion.

[TheRooster]

I got a GS1100 Aluminum Swingarm

[makenzie71]

Look for a TL1000S or TL1000R swingarm...preferably the R because the braced swingarm looks so much cooler.

Anyway...the tops of the TL swingarms are flat and about 1.25" wide, they accomidate a 6" wheel, and they're short. A lot of linked suspension swingarms are longer and the TL's had a rotary damper setup that didn't require that extra length...makes them ideal for this kind of thing.

I used an R swingarm on a CB900 project. I took some heavy guage box tubing and cut out mounts for the bottoms of my shock. I then just drilled the swingarma nd bolted the mounts through the spars. held great. Looked great with the 6" wheel, too.

[80GS1000]

If you want a 00+ GSXR front end, you have to monoshock the rear. This is because the newer front ends are so short that with a dual shock rear the ride height is unacceptable for anything except for a drag bike. With mine I was able to adjust the ride height and headstock rake angle to the correct and appropriate levels by the position of the monoshock frame mounts. It was quite the lowrider with just the 04 GSXR 1000 front end.

Others have had luck with using a Bandit 1200 swingarm with shock mounting lugs welded on combined with a GSXR 1100 front end. The B12 swinger lets you use your desired dualshock rear setup and the GSXR 1100 front end is almost the same length as the GS front end so you preserve ride height. The B12 rear wheels have that nice looking 3 spoke design too.

Here's some more info: http://www.robwilton.com/xtech.html

[makenzie71]

If you want to maintain stock height you can run with a dirtbike setup...I've done that as well, but finding adequate springs can be nightmarish. I used a CR250 front end on that same CB900 job but I had beefier springs...

[Mark M]

If you want to maintain stock height you can run with a dirtbike setup...I've done that as well, but finding adequate springs can be nightmarish. I used a CR250 front end on that same CB900 job but I had beefier springs...

What did you do for brakes? Or did you just run one disc?

Mark

[makenzie71]

At the time there were no brakes. I ran a CBR600 enkei wheel up front...had I had time to tweak before ditching the project I would have pulled one of the discs and cut a hanger to relocate the caliper to fit the other properly.

[Sc0ttzi]

I'm a little confused with what you mean by "low rider" with the front end being so short. Is it that the bike leans too far forward with a dual sided shock swingarm? If this is the case would it be possible to reposition the shock mounts, or to used shorter shocks?

[TheCafeKid]

I'm a little confused with what you mean by "low rider" with the front end being so short. Is it that the bike leans too far forward with a dual sided shock swingarm? If this is the case would it be possible to reposition the shock mounts, or to used shorter shocks?

You really start messing with the geometry of the bike at that point. Swapping over to "modern" front and rear on the GSs is pretty common, and the best ways to go about it seem to be what 80GS1000 suggested, as well as isleoman, Katman, and a few others. I am in the process of collecting the parts to do some conversions myself on my 1100ES, tho i will be using 88 GSXR1100 wheels, which look just like stock, except can accomodate a 150 or 160 rear, and a 110 or 120 front tire. I will also be able to modify the STOCK GS swinger to accept the set up, which will make it look even more stock. Incase you havent figured it out, MY goal is to improve handling a bit, while maintaining a damn near stock look.

If you mess with the geometry on these old frames alot, you are setting up for trouble, as they simply cant deal with the flex, and no bike feels good in the corners when the frame feels like it has a hinge in the middle.

[80GS1000]

I'm a little confused with what you mean by "low rider" with the front end being so short. Is it that the bike leans too far forward with a dual sided shock swingarm? If this is the case would it be possible to reposition the shock mounts, or to used shorter shocks?

The shorter front forks cause the bike to ride lower than stock. A couple of pics to illustrate, this is very early on in my project just after the GSXR 1000 front end was installed. There was only had 2" of ground clearance under the header.





In order to get the Gixxer front end to work I had to raise the rear end by monoshocking and making a custom 4-2-1 header so there's enough ground clearance under the exhaust (about 5"). To my knowledge there aren't rear dual shocks long enough to make a GSXR 1000 front end work, maybe you'll pioneer this.

To preserve stock ride height with a dual shock rear setup you probably want a GSXR 1100 front end.

[TheCafeKid]

The shorter front forks cause the bike to ride lower than stock. A couple of pics to illustrate, this is very early on in my project just after the GSXR 1000 front end was installed. There was only had 2" of ground clearance under the header.





In order to get the Gixxer front end to work I had to raise the rear end by monoshocking and making a custom 4-2-1 header so there's enough ground clearance under the exhaust (about 5"). To my knowledge there aren't rear dual shocks long enough to make a GSXR 1000 front end work, maybe you'll pioneer this.

To preserve stock ride height with a dual shock rear setup you probably want a GSXR 1100 front end.

Approximately how long would they have to be, the dual shocks? I have seen them in as long as 15inch lengths...thats 2 inches over stock of the GS shocks...still not enough?

[80GS1000]

If you mess with the geometry on these old frames alot, you are setting up for trouble, as they simply cant deal with the flex, and no bike feels good in the corners when the frame feels like it has a hinge in the middle.

+1. If you start going with more rigid, newer running gear (forks/swingarm) frame bracing becomes almost a necessity to get the maximum gain from the upgrades. Especially if you like cornering aggressively. Can't have stiff running gear and a spaghetti frame.

[tone]

For a gs i'd go for a gsxr1100k or bandit 12 front end as they are long enough to maintain ride height but you will need to mess with bearings etc (both normal forks btw) if i wanted usd forks the first choice has to be gsxr1100wp as they are also the right length & a direct fit

ive done all the above swaps a few times so am speaking from experiance, buying a complete front end is always preferable as theres no messing around making wheels brakes etc fit

you can get a 4.5" wheel & 160 tyre in the stock swingarn easilly enough & a 5.5" with a 180 is possible but not at all easy if keeping the stock arm, i've seen zrx1100 twin shock arms fitted too but cant comment on that as ive not done it, basically any mono gsxr arm will go easilly enough if you are willing to go the mono route

hope it helps

[Sc0ttzi]

80GS1000, my question now is would you have a guess as to how much the shock mounts on a dual shocked swingarm have to be jacked to reach the same height as your bike if you were to used stock, or stock length shocks?