91 GSXR750 swing arm on 83 GS750E question.

[djee]

Great thank you.
I'll look into all this and double check again when I'm done

My bike is an 750E '84 (canadian) and the donnor is GSXR750 1991.

Forget about the tape measure....I'll use the galiper to make sure everything is in order.

[djee]

Rear wheel centered,

Hey,
So finally had some time this week end.
Found out that the rear wheel is 8mm offset right in the swing arm.
Centered the wheel in the frame using the center of the swing arm +4mm.
Made sure my wheel axle was parralel to swing arm pivot.
Then double checked with the string method (http://www.motorcyclistonline.com/ho...els/index.html)
Ended up that my wheel is "perfectly" centered with the front (±1mm).

Then, checked the sprocket alignment, again with the string method:
Using the gixxer rear sprocket and original wheel spacers and keeping the front one at it's original position (just to check) I found that my rear sprocket is 10mm off on the exterior side and it wouldn't clear the frame.

So basically my rear sprocket need to go ±10mm inside.

My first thought is to shave the drum (where the sprocket attach) by 10mm. Looks like the chain would clear the 170 rear tire.

Is this the thing to do ? Don't remember to have read such a thing on the different conversion posts.

I am planning to go with a 530 chain set-up.

Thanks,

[posplayr]

Hey,
So finally had some time this week end.
Found out that the rear wheel is 8mm offset right in the swing arm.
Centered the wheel in the frame using the center of the swing arm +4mm.
Made sure my wheel axle was parralel to swing arm pivot.
Then double checked with the string method (http://www.motorcyclistonline.com/ho...els/index.html)
Ended up that my wheel is "perfectly" centered with the front (±1mm).

Then, checked the sprocket alignment, again with the string method:
Using the gixxer rear sprocket and original wheel spacers and keeping the front one at it's original position (just to check) I found that my rear sprocket is 10mm off on the exterior side and it wouldn't clear the frame.

So basically my rear sprocket need to go ±10mm inside.

My first thought is to shave the drum (where the sprocket attach) by 10mm. Looks like the chain would clear the 170 rear tire.

Is this the thing to do ? Don't remember to have read such a thing on the different conversion posts.

I am planning to go with a 530 chain set-up.

Thanks,

As stated earlier most of these conversions use the GS sprocket carrier in the GSXR wheel. You can take a couple of mm off of it but I think 10mm is way to much.

Are you using an offset countersprocket? 5.5" wheels usually use 5/8" offset

[djee]

As stated earlier most of these conversions use the GS sprocket carrier in the GSXR wheel.

What would be the advantage with the gs sprocket carrier ?
I believe I measured the same sprocket position with the gs carrier vs the gsxr carrier.

Are you using an offset countersprocket? 5.5" wheels usually use 5/8" offset

I am planning on but actually don't have it with me. At first sight 5/8 (15mm) looks like the chain will rub the frame.

[salty_monk]

GS Carrier is slimmer than the GSXR one - it moves the sprocket closer inboard moving the chain towards the Tyre which is what you want to do....

[posplayr]

GS Carrier is slimmer than the GSXR one - it moves the sprocket closer inboard moving the chain towards the Tyre which is what you want to do....

I did not know for sure as I just used 88 GSXR 1100 stuff.

So Djee if you can measure the thickness difference of the carriers, that will give you an adjustment to the stock spacers. Then reassemble and check for chain clearance.

[salty_monk]

I think there is about 1/4" of meat on a GS carrier sprocket surface that could be machined off to get a sprocket into alignment if necessary too. Any more than that would leave things a bit thin....

On my 750 I am running a 6mm front spacer with a 530-520 conversion sprocket (has a lump on one side) with the lump on the inside rather than the outside.

Couple with some adjustments on the sprocket hub in order to move it in closer to the wheel I am able to run 1 170 tyre on a 5.5" wheel on a stock swingarm.





Dan

[posplayr]

I think there is about 1/4" of meat on a GS carrier sprocket surface that could be machined off to get a sprocket into alignment if necessary too. Any more than that would leave things a bit thin....

On my 750 I am running a 6mm front spacer with a 530-520 conversion sprocket (has a lump on one side) with the lump on the inside rather than the outside.

Couple with some adjustments on the sprocket hub in order to move it in closer to the wheel I am able to run 1 170 tyre on a 5.5" wheel on a stock swingarm.





Dan

Looks nice and you have tonnes of clearance. What shock you got on there? Did it boost rear ride height?

[salty_monk]

It's a Ducati shock. Stock length & using the stock spring but the Ducati shock allows application of about 2" of preload if required where as stock hydraulic preload adjuster had only 3/4" range.

To gain extra clearance I run the wheel slightly further back in the swingarm than stock but I think that I may have been ok even in the stock position looking at it now

You'll see it for yourself in July all being well

[posplayr]

It's a Ducati shock. Stock length & using the stock spring but the Ducati shock allows application of about 2" of preload if required where as stock hydraulic preload adjuster had only 3/4" range.

To gain extra clearance I run the wheel slightly further back in the swingarm than stock but I think that I may have been ok even in the stock position looking at it now

You'll see it for yourself in July all being well

Looking forward to it. Just putting my Vac request in today

[salty_monk]

Me too... Skunk is in pieces now in prep!

[djee]

getting there slowly...

Gentlemen,
Well finalize alignement of the rear wheel a few weeks ago...I finally use the string method and compare with calculations on new vs old swing arm and it fitted within a mm or two.
Also had spacers made to centered the swing arm I had previously slightly shaved.
Ending up very close to the 5/8 offset sprocket in the front. I will finalize measuring once my suspension is all mounted and fixed.

So now I am on the rear suspension mounts...(I know it's been a while..putting only 1 or 2 hours weekly is not very fast !)....
Mounted a preliminary mock-up to see how it will look like.
Used pictures I took of a GSXR 1100 to base my dimension, I know it's not the same bike but at least I had a point of reference.
We rapidly welded mounts. ===> Note that this will not be the final design as it is not strong enough...only to try out positions.<===
Here's some pics:




I have put back the bike on it's wheels with the gixxer fork and in terms of height it's a little low but looks balanced and leveled so I would assume the height of mount is with in parameters.

Compare my top mount with some pic I saw (like Tone earlier in this tread) and looks like I would need to get the shock closer to the frame
and change lower one accordingly.

What do you guys think ?