GSX-R Rear Wheel Swap...Quick Question

[Turd Ferguson]

As some of us know, many of the old GSX-R rear wheels have 20mm I.D. bearings and the GS has 17mm I.D. bearings.  Does this simply mean that the rear axle on the GS has approximately a 17mm O.D.?  If so...why can't the rear of the bike be drilled out to accept a 20mm O.D. axle so that a wider GSX-R rear wheel can be swapped on?

I have been looking at the 5 or 5.5 inch rear wheels, it seems like if I switched axle's it shouldn't be impossible.  I could then use the GSX-R cush drive and sprocket.  I'd have to find a wheel that fits, and I'd have to find a sprocket from a bike with a 520 chain.

I tried searching...nothing came up.  Anyone have any insight?

-Turd.

[onefastgs500]

you just use the gs bearings in tyhe gsxr wheel use the gs cush drive and spacers shave the rear caliper hanger to about 10mm thick @ the axle look for a 4.5inch gsxr wheel 88-89 i think pm me w/ questions

[sledge]

We touched on a similar subject a few weeks ago.

http://gstwins.com/gsboard/index.php?topic=24346.0

[Turd Ferguson]

I should have mentioned that I am very familiar with the common 88-89 GSX-R 750 rear wheel swap.  I am looking for something wider.

Thanks Sledge, from that link you gave me it looks like I'll be able to find wheel and hub bearings that will fit the GSX-R wheel AND my 17mm axle if I look up some industrial supply type bearing companies.

The idea here is...I want to fit a wide wheel on my bike, but I want to keep my 17mm axle.  Now the challenge is to find a wheel with a sprocket for a 520 chain that wont totaly destroy my chainline.

Hopefully I'll end up with a 180 or 190 rear tire on a GS500F here in a few months...

-Turd.

[JetSwing]

how do you exactly plan to put 180 or 190 on a gs? a new swing arm? an entirely new back-end? what about the chain alignment? anyway this doesn't make too much sense...

[Turd Ferguson]

The factory swingarm will do, but it'll be tight.  As far as chain alightment, I'll probably buy the wheel and hub, mount it on the bike and see where I need to go from there.  Many GSX-R hubs have a sprocket that is spaced out quite far (compared to the GS) to clear a large tire.  If everything goes correctly, it wont be spaced out so far that the chain alignment is way off.  I am, however, willing to move the motor over a few millimeters to get a proper chainline.

It seems that the chainline is the only thing holding me back.  If the wheel is centered well in the swingarm, a large tire like this will fit.  This has been done before you know...

http://gstwins.com/gsboard/index.php?topic=22948.0

Take a look at this guys swingarm, it's factory.  I've taken several measurements on the swingarm and a 180 is going to be tight.  A 190 would be super tight, I'm not sure how this guy fit it.

I'm a mechanical engineer...this is what I do.  The way I see it, by the time I sell my brand new 130 bt45 tire, my brand new rear wheel, sprocket and rotor...I will have spent $100-$150 on this project.  I work in a mechanical engineering lab and I spend many hours a week in a machine shop.  It might take me a while to work out the kinks, but it CAN BE DONE. 

-Turd.

[onefastgs500]

look at other manufacturers as well yamaha wheels are very similar might have a narrower cush drive

[Turd Ferguson]

look at other manufacturers as well yamaha wheels are very similar might have a narrower cush drive

Will do, thanks for the tip!  Ideally, I'd like to use a wheel that has the "twisted" spoke design like the GS, hence why I am looking for an early 90's GSX-R wheel.

-Turd.

[Cal Amari]

Of course it CAN be done, but I personally wouldn't want to add any weight to the already weak-lunged GS, and those ultra-wide tires have got to be heavier than a size closer to stock. There comes a point in time where making changes like that constitutes overkill... I don't understand why you'd want to make a slow motorcycle even slower; I'd prefer to build a 541 engine and get more performance, but that's just me. Maybe you want a way to showcase your engineering skills, maybe you're bored... all it really amounts to is parts-bin engineering (not that there's anything WRONG with that), which I've been guilty of many times over the years. Mill this, grind that, install stock or slightly modified parts from other models... I'd be more inpressed if you forged your own pistons, or cast your own wheels and swingarm.

Well, if you have the time, money, energy, and resources, more power to you. Good luck finding suitable parts... hope it turns out well...

[Turd Ferguson]

A good post as always by Cal Amari.  I've always enjoyed your input on every thread I've seen you join in on.

For me, owning a GS is not about speed.  I don't race the bike, I don't participate in track-days.  I'd have to admit, I wouldn't be cruising around town on a GS500 if motorcycling, to me, was all about speed.  I enjoy cruising and riding around town with friends at a rather casual pace.  I know a wide tire will have negative effects on handling and acceleration.  Honestly, these effects will be small, especially for a guy like myself who rarely sees the other side of 6,500 RPM. 

Boredom?  Probably.  I've always had some sort of hobby that has allowed me to modify and change things that are somewhat outside the norm.  First, cars.  Next, computers.  Now?  My GS500.

If I wanted to race the bike...maybe I would be creating my own parts that related to performance.  I'm not looking to make a giant project out of this...I'm simply looking to have something to play around with that has a relatively small cost.

Thanks for the input everyone!

-Turd.

[Cal Amari]

Once again, I've learned something from reading another perspective... the truth is, I'm not a speed freak, I'm more obsessed with handling. Knee-dragging is my particular obsession; I can't ever get enough of cornering (must be an inherent inner-ear imbalance)... if I had my choice, I'd live at Laguna Seca (or whatever they call it now) and spend every free moment attacking the Corkscrew from both directions. Hell, I'd drag my ears if they weren't trapped inside my helmet...

The GS is maybe one notch below where I'd prefer it to be from a power perspective, which is why I mentioned building a 541 engine. The GS doesn't handle like an FZR400, but with the right suspension changes, it really doesn't need to apologize to any other four-stroke motorcycle sold in the US. No one will ever mistake it for a purpose-built roadracer, but it suits me, especially with my favorite passenger holding on to me, living her own motorcycle fantasies, which are just as intense, though completely unrelated to mine...

Kick some ass, TF; I can't wait to see the results...

[makenzie71]

First...no, you're not going to put a 190 in the GS's swingarm.  I already tried mounting up my TLS wheel...a 180, maybe, but it will be very tight.  ALmost "unsafe" tight.

Your best bet is to grab up a later model GSXR 750~1000~later 600~etc wheel.  They have 22mm rear axles if I'm not mistaken (I'll double check for you later)...at any rate they have a wide enough axle to accomidate a sleeve.  You can have one machined out of mild steel (you want to use milder steels for shafts and sleeves) for less than $100...you'll just have to get your width right but that really shouldn't be that difficult.

Make your you get a full rear assembly...wheel, sprocket and rotor cariers, cush, rotor, and a caliper hanger and caliper too would be beneficial.  It'll be much easier making the whole thing fit into a single gs piece than making 5 GSXR things fit in 5 GS pieces.

[Turd Ferguson]

Hey Makenzie, thanks for the reply!  So you slid your TLS wheel into the GS swingarm with a 180 on it?  How tight are we talking?  Your right, if it's 1/8" or closer to the swingarm on each side...thats just not safe.  Was your obstruction the swingarm or the brake rod and chain?

-Turd.

[makenzie71]

The obstruction was, actually, everything.  I only had a 190 to try and fit and the rubber was rubbing the arm pretty heavy.  Everything else was in the way but alterable, the main thing was the tires width.  If you really want to run with this you need to look into swingarms designed to accomidate a wider tire.  I know that the earlier GSXR 750 swingarms will accomidate a 180 and fit in the GS frame with minimal modification.

If you're doing this for a total-show purpose, you might want to look into an sssa.  You can buy 6.5" rims to fit almost any SSSA hub and run a 225 if you really wanted to go wide...

[sledge]

Turd??
This thread has really got me thinking and would like to offer you a suggestion. Last year I bought a used swingarm, I had it shot blasted and repainted it before replacing all the bearings in the linkage and swapping it for the original one. The original was rusting in the `crotch`and looked crap. If what you propose  landed on my desk as a project and after thinking about the design of the swingarm I would be looking  to modify the original one by grinding off the 2 arms from the pivot tube and making and rewelding on 2 new arms made from rectangular  box-section spaced wide enough where it matters to accomodate the larger tyre. I think this option could be a viable proposition and seriously worth looking into. Maybe you could get a used arm from a breaker then take it to a few local Engineering shops and get their comments and views. Ok there will be other issues to consider like axlebolt and spacer length and sprocket and brake-disc alignment. The arm would have to be carefully measured and jigged, and machined to accomodate the tensioners but its by no means impossible for someone experienced and knowledgeable enough.

[makenzie71]

Sledge, as easy and simple a process as what you describe may sound, it'll be far easier to just buy a swingarm wide enough for the wheel.

[werase643]

QUOTE....."I'm a mechanical engineer...this is what I do. "

Turd might have a clue what to do and probably has the equipment to modify what ever he wants

[makenzie71]

^...most random post ever.

[werase643]

the concern to me would be the hub width on the 90-up wheels
the GS width at the axle is....8.5 ish inches
the GSXR stuff is 10 ish

that is a lot of trimming to get to fit
on the 88-89 wheel at least you can use the GS cush and save an inch on the width

[werase643]

ya Mack
real random
in ref to sledges post.....   Maybe you could get a used arm from a breaker then take it to a few local Engineering shops and get their comments and views.


i like the mod to your TL....got rid of that dang rotory dampener