GSXR Wheel Swap

[DB Cooper]

Hey Guys.
So I finally got all the parts I need, and it's now warm enough to work on the FJ and get the rear 17" conversion done up.
I did a quick mock up tonight, mounting the wheel and all the bits into the swingarm, no tire on the rim yet.
I am using this write up, http://www.fjowners.com/index.php?topic=3380.0 , and every thing seems to work well so far.  The only issue I have, is that the FJ axle seems to be too short.  After mounting everything, and torquing the axle, the nut isn't on far enough to expose the hole in the axle for the cotter key to go through. Anyone else run into this? My FJ is an 89 3CV,  and I'm using the 90 GSXR 750 wheel which is 5.5" thick. I used the factory Suzuki spacer on the brake side between the caliper and the bearing, and the Suzuki spacer on the the chain side between the cush drive hub and swing arm. The mod calls for adding two 4mm spacers, but the closet I could get my hands on measure only 3.30 mm thick. Just wondering where I'm loosing out on axle thread, especially if my spacers are less in thickness than called for. 
Any thoughts?
Kevin 

[FJmonkey]

Hey Guys.
So I finally got all the parts I need, and it's now warm enough to work on the FJ and get the rear 17" conversion done up.
I did a quick mock up tonight, mounting the wheel and all the bits into the swingarm, no tire on the rim yet.
I am using this write up, http://www.fjowners.com/index.php?topic=3380.0 , and every thing seems to work well so far.  The only issue I have, is that the FJ axle seems to be too short.  After mounting everything, and torquing the axle, the nut isn't on far enough to expose the hole in the axle for the cotter key to go through. Anyone else run into this? My FJ is an 89 3CV,  and I'm using the 90 GSXR 750 wheel which is 5.5" thick. I used the factory Suzuki spacer on the brake side between the caliper and the bearing, and the Suzuki spacer on the the chain side between the cush drive hub and swing arm. The mod calls for adding two 4mm spacers, but the closet I could get my hands on measure only 3.30 mm thick. Just wondering where I'm loosing out on axle thread, especially if my spacers are less in thickness than called for. 
Any thoughts?
Kevin 

I have a 92' GSXR 750 rear wheel on my ass end (86'). I needed a spacer on the chain side cuz the GSXR wheel is not centered like my 86'. It was close to 3/8 of an inch to keep the rear centered with the front. I made some other slight front sprockets mods to keep the chain aligned. The chain still hits the 180/55 tire on the rear. I want to move over to the VFR off-set sprocket to keep the chain from removing the Left side of my tires...

[markmartin]

It sounds like the axle should reach Kevin.  I have to ask; are you sure you're using the FJ axle ?  Have you by any chance put an extra washer out side the swingarm on the brake side of the axle?

I used the GSXR spacer on the brake side (the spool of tread looking spacer) and the solid spacer on the the sprocket side as you mentioned in your post. I had referred to a previous post by you to get the brake side spacer right, so I'm thinking that you have the right  one there.  The only other variable is the sprocket side spacer thickness.  I can drop my wheel this weekend and check the thickness of this spacer for you if need be.  I can check other measurements also while Im there; axle, wheel, etc. -- so take me up on it if you need to.

As for the extra washers used as spacers to fit the FJ swing arm, in I ended up with .258" (6.5mm) of washer on the brake side, and .075 (1.9mm)on the sprocket side.  Using the axle for a gauge, I had compared the total width of the GSXR (spacers, brake, wheel),to that of the FJ, to replicate the total width required for the GSXR wheel assembly and (washer) spacers, so I'm pretty sure I'm close with these total measurements, however I did not record this measurement.


Hope this all makes some sense.   

[markmartin]

I needed a spacer on the chain side cuz the GSXR wheel is not centered like my 86'. It was close to 3/8 of an inch to keep the rear centered with the front. I made some other slight front sprockets mods to keep the chain aligned. The chain still hits the 180/55 tire on the rear. I want to move over to the VFR off-set sprocket to keep the chain from removing the Left side of my tires...

I measured the stock FJ wheel as it sat in the swing arm (to my knowledge, I had a stock set up) and this is what I got:

The stock wheel set up has the FJ wheel off center of the swing arm by 3/64ths of an inch to the right of center.  I was measuring this with a combination square, squared off to the outside of the swing arm, measuring to the wheel closer at the front side (motor side) of the wheel. Also, the stock FJ distance from the outside of the swing arm to the teeth on the sprocket was an even 2.100 " ,(measured with a vernier caliper).  

On the GSXR, I used (off the shelf washers)  .258" spacers on the brake side and .075 spacer on the sprocket side. This put my GSXR wheel a weak 1/32nd  to the right of dead center, and a distance of  2.055" to the sprocket. Incidentally, I used an JT 38tooth sprocket, and flipped it to get the teeth further from the sprocket..

Now, I could get custom spacers to tweak the wheel off center to the right another .0312" or so to more to mimic the original FJ measurement and consequently move my sprocket closer to the original measurement.  I don't know if this is spitting hairs .  Also, I was perplexed by the original wheel being off of center of the swingarm.  Granted it may be this way by design to have the wheel centered to the bike frame.

[DB Cooper]

Hey Mark.
Funney you should mention the axle. The best way I found to line everything up was to insert the OE Suzuki axle in from the chain side, then work back through the brake side with the FJ Axle. The very first thing I looked at was if I had used the FJ axle or not, and I did. I'm missing about a 5-6 mm of thread to expose the hole for the cotter key, so I don't think it's a question of the spacer. Also, visually, the chain lines up really nice. One thing I did notice, and wondering if you could have a look on your setup, is that the  cushdrive hub doesn't "seat" all the way into the wheel hub. There is about 3 mm exposed, not sure if this is normal. I'll take a picture tonight a and post it. It was a late night, and I was tired so maybe I'm missing something obvious. Don't worry about dropping your axle, I'm sure I notice something when I go out later to tackle it.
Thanks
Kevin

[markmartin]

One thing I did notice, and wondering if you could have a look on your setup, is that the  cushdrive hub doesn't "seat" all the way into the wheel hub. There is about 3 mm exposed, not sure if this is normal.

Here you go Kevin, I think you've found the problem.  The cush drive hub sits IN from flush about .5 mm  to  1 mm or so. (guestimate by feel).  Sounds like the rubber dampers may not be seated all the way in.  ?

[DB Cooper]

That probably is the issue. If I install the cushdrive onto the wheel without the spacer that goes between them, it will fit flush. I guess I have the wrong spacer. I know this one is the right diameter, just the wrong length. I can machine it down so the hub will fit flush.
Thanks Mark!!!!!

[craigo]

Mr Cooper,

With all due respect, you should not have to machine anything. My wheel mounting went without any machining. And this is my guide you are using.

I bought the washers off the shelf at Ace Hardware. I used the entire wheelpack from the GSXR. All the parts came from the same bike. If what you bought was all from the same model year GSXR, then you should have the same results as me.

If you used anymore than 2 washers, one on either side of the wheel pack, you have too many washers. If you went with more than one washer on each side of the inside the swing arm, and have that gap, I am surprised that you were able to get the wheel pack to fit.

You mentioned the spacer that fits between the sprocket hub and the wheel. So we know that's good. The only other item is the axel. You must be using the Suzuki one by accident.

Anything I can do to help, let me know.

CraigO

[DB Cooper]

Hey Guys.
I just got home and went out to the garage. I instantly saw the problem. The solid spacer between the swing arm and the cushdrive is way more exposed than the way it is in Marks photo. I'll disassemble tommorow and find out why.  It may not have seated correctly. Also, you can see the difference in how much Marks cushdrive sits deeper into the wheel than mine. I'll have to carefully measure the inner spacer and see why, as the hub sits like Marks' does if I remove that spacer.
Hey Craigo.
I can't say just how invaluble your write up on this swap has been. Unfortunately, these parts came from a few different suppliers, so some of the parts may from a different model.
Mark, thanks for the photo, a real big help!
Kevin 

[craigo]

Hey Cooper,

Yeah, the GSXR spacer is not in the wheel like this:


And this is the gap between the hub and wheel on my bike. I hope it comes out as the light and black wheels makes it hard for a good pic.


CraigO

[DB Cooper]

Curiousity got the better of me, so and I went out and took everything apart. I took the FJ wheel, spacers and caliper carrier and assembled it on my bench in the order it would be on the bike. Then I scribed a mark on the axle where it came through the spacer on the chain side. Then I did the same setup with the gsxr wheel and spacers,with out the added washers and the measurement was the same.
Craigo,
I'm assuming that the washers are required for chain alignment? If so, first I'll correct the way the cushdrive protrudes out of the wheel (see the pictures below). Then I'll remount the FJ wheel on the bike, and take some accurate measurements for the sprocket to swingarm distance, and wheel center.  My thinking is that the spacer I have probably came from a different model, and is thicker than the one you guys have.  I may get lucky and not need the washers. I'll keep you posted.
Thanks for the help!
Kevin

I took these pictures of the cushdrive with and without the inner spacer. Either the spacer is wrong, or possibly the bearing was never seated properly in the hub.

[markmartin]

I took the FJ wheel, spacers and caliper carrier and assembled it on my bench in the order it would be on the bike. Then I scribed a mark on the axle where it came through the spacer on the chain side. Then I did the same setup with the gsxr wheel and spacers,with out the added washers and the measurement was the same.

I used the same procedure when doing mine, and the GSXR wheel assembly was shorter than the FJ assembly by about 8 or 8.5mm ; thus the addition of washers. 

   Either the spacer is wrong, or possibly the bearing was never seated properly in the hub.

That sounds right to me. 

[craigo]

Yeah, what Mark said about the reason for the spacers. The wheel pack on the GSXR is narrower than the FJ pack. Hence the washers.

I have to say it appears the inner spacer between the hub and wheel might be your problem. The sprocket hub just does not fit like it should. If memory serves, that is the right spacer, so it could be the bearings are not seated correctly. But I'm feeling that the problem is in there.

This is why it was so important to me to source the parts from the same bike. Enough to make mention of it in the write up.

Again, anything I can help you with, let me know,

CraigO

[woodman]

Hey Guys.
I just got home and went out to the garage. I instantly saw the problem. The solid spacer between the swing arm and the cushdrive is way more exposed than the way it is in Marks photo. I'll disassemble tommorow and find out why.  It may not have seated correctly. Also, you can see the difference in how much Marks cushdrive sits deeper into the wheel than mine. I'll have to carefully measure the inner spacer and see why, as the hub sits like Marks' does if I remove that spacer.
Hey Craigo.
I can't say just how invaluble your write up on this swap has been. Unfortunately, these parts came from a few different suppliers, so some of the parts may from a different model.
Mark, thanks for the photo, a real big help!
Kevin 

Hi i have the GSXR wheel mod and my spacer fits deeper into the wheel than yours will try to upload a few photos this weekend.cheers! Woody.

[DB Cooper]

I have to agree on the size of the inner spacer. However, it looks to be only about 4mm or so off, which still won't get me enough axle thread for the cotter key. I'm still thinking that my chain side spacer may be a little thicker as well. Once I correct the inner spacer size, I'll get a better idea on the spacer thickness, and what I'll have to do to shim it up.
Hey Craigo.
Ya, I hear you on the "same bike" stuff, I tried, but there just wasn't anything around me to be had at a reasonable cost. One guy had a rolling frame and engine, but he wouldn't sell it for any less than $750. So I opted for parts, knowing someone who can do some machine work for me.
Thanks for the help
Kevin