GS1100 vs GSXR600 Swingarm

Supercharged, just a thought, however when I put a GS11 swingarm on my GS750 frame, I simply drilled the 750 frame to accept the 11's pivot bolt and retained all the aluminum swinger's bits. G

I have not done this for a bearing set, however, he is right about this. If you use a softer metal the bearings will eat into it, bind, slop, or otherwise behave badly.

My question, does the swingarm already have bushings? If so, what is the difference in diameter between those and the stock bolt? Also, can you just enlarge the holes?

On the machining side, he is right about distortion over length. Unless a fairly stout bar is used, the 8+" length will lead to some issues. Also, using the 3 section idea would be a good way to solve this.

On the bearing side, replacing the bearings with a sealed roller setup would work as well if you can find the right size. You may also consider using 2 sets of bearings on each side to keep a similar load area on each side of the pivot bolt as the stock setup. A shoulder/adapter would be easy to make for this application though I would expect to make it out of a decent steel as the aluminum may get pushed around.

This is my opinion, though I am not a professional machinist or a professional engineer. What ever you do to modify from stock you do at your own risk. Therefore, when in doubt, build it stout!

KawiConvert - Thanks for the input and re-assurance I am on the right track. I would prefer to have it done right.

Since this is a 1998 GSXR arm, the ID of the needle bearing is 30mm and the GSXR bolt is a whopping (compared to the KZ) 25mm.

How feasible is it to have from the outside in...
- the arm ID = 40mm (stock GSXR)
- the needle bearings ID = 30mm (stock GSXR)
- the harderend collar ID = 25mm (stock GSXR)
- another collar ID = 16mm = MODIFICATION
- the KZ pivot bolt = 16mm (stock KZ)
My guess is this will put metal to metal and a potential unprotect pivot spot - or will it take the path of least resistance and pivot on the needle bearings?

attached is an image of my notes on the Arm

how about bushings instead of bearings?

PLUMMEN wrote:

how about bushings instead of bearings?

Heretic!

supercharged wrote:

KawiConvert - Thanks for the input and re-assurance I am on the right track. I would prefer to have it done right.

Since this is a 1998 GSXR arm, the ID of the needle bearing is 30mm and the GSXR bolt is a whopping (compared to the KZ) 25mm.

How feasible is it to have from the outside in...
- the arm ID = 40mm (stock GSXR)
- the needle bearings ID = 30mm (stock GSXR)
- the harderend collar ID = 25mm (stock GSXR)
- another collar ID = 16mm = MODIFICATION
- the KZ pivot bolt = 16mm (stock KZ)
My guess is this will put metal to metal and a potential unprotect pivot spot - or will it take the path of least resistance and pivot on the needle bearings?

My suggestion would be to use the stock bearing and sleeve as you have, but machine a sleeve for each end that is about the width of the stock KZ bearings (about 2" per side in my 650). Make it 16mm ID, 25mm OD with enough clearance to slip ever so slightly. Have them leave a tiny lip on the od, chamfer the ID of the bearing sleeve, and then put locktite on the new 16-25mm bushing, slide them together and let it dry. You'll have a locked in sleeve adapter and only have 2 parts to make.

I'd make them for you, but it would be several weeks before I would have time. Its about 25+ shipping for 1' of stainless or for aluminum (7068) about 35 + shipping. Just ideas, again, go with what works for you purposes.

Thanks - so that is where I was heading, but the details you provided should help.

Since I am entering my busiest time, I may not get this handled locally, so I will keep you informed.

Also, if you lock your new sleeve with the bearing sleeve and keep the bearings greased, the bearings should always be the ones to turn. If not, the bearings are shot and your sleeve is too small. It should be fine, just make sure you have enough length on your sleeve adapter as it distributes the load from the swingarm. Too narrow and you may start to sheer the swingarm bolt (I've seen this on a used dirtbike I picked up).

Convert - what do you think of this idea...

Insert a sealed roller bearing 30mm OD and 16mm ID in the needle bearings. Then the bolt would fit the ID of the roller bearing.

This, providing such a bearing exists, would eliminate any fabbing. If possible, I would use 2 bearings each side to accommodate the distribution.

I ask this, because I have another arm that I believe the technique would be possible, since I have found the bearings.

I did a very quick search through the barden catalog and couldn't find any 30 or 40mm bearings. I think the sleeve adapter is your best and simplest bet. You don't have to have high precision or parts ground like you would if you make a new one piece sleeve, and you are retaining the stock bearings. Its just a matter of making the sleeve. You could use bronze for the adapter as well and have a bushing in addition to the bearing.

Hey guys,

I've been kinda neglecting my swingarm project so I could ride for sure this summer. But...

I still need some sort of sleeve with an OD 25mm and ID 16mm. I was having trouble finding a friend with long enough tooling for the spacer ID (need at least an 8" boring bar). I was thinking...

I have two stock KZ swingarms, one was in my accident, the other on the bike currently. If I cut one apart/cut off the bearing race and turn down the race to the ID of my GSXR swingarm (25mm), I should be able to run it inside there right? I mean,

A. It's steel
B. I would be running two sets of bearings,
1. One set still in the orginal swingarm bearing race
2. The others in the GSXR swingarm.
C. I could use my old swingarm pivot bolt

As long as I turn down the KZ bearing race properly for a good fit inside the GSXR swingarm bearings, I don't see a reason why this wouldn't work, right?

KawiConvert wrote:

PLUMMEN wrote:

how about bushings instead of bearings?

Heretic!

if ya keep em greased bushings will last a long time,much easier to make also if you need to replace one