91 GSXR750 swing arm on 83 GS750E question.

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 ?

[salty_monk]

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

[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]

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]

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]

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]

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]

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....

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.

[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

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,

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.

[posplayr]

I went back and looked at the pics. Just judging from where your straight edges line up on the frame, it is saying the wheel is close to centered in the frame. This is not going to be accurate unless you get the rear axle parallel to the swing arm pivot.

I forgot is this an 1150? or 750/750? Regardless the GS pivot bosses are likely centered, but that GSXR swing arm may not be. IIRC, the Bandit is about 3/16" offset.

Also as you have probably surmised, it is going to be tough getting a rear brake push rod to fit between frame and swing arm on the rights side (is the 1150 set up that way?).

If you look at my thread, I was able to offset the whole swing arm to the left to give more space and changed the wheel spacers to compensate.

But before you go too far with this take a look at where you are with the chain. Are you even close? Most of these GSXR conversions retain the stock GS sprocket carrier. That means new spacers . You have the tread the chain between tire and frame. With my 4.5x18 and 170/60-18 I had about 4.5-5.0mm clearance on either side using a 530 chain. A 5.5x17 with 180/55-17 you are ususally down to 2.0 mm or so either side.

At this point you are not just doing an alignment between front and rear. You are tring to find the right combination to get the rear wheel centered and have the chain run straight up to the countersprocket. Basic steps are.

1.) Wheel has to be centered in the frame (within 1/8" (3mm) or better.

2.) Align the rear wheel axle with the swingarm pivots by measuring pivot center to axle center as best as possible ( to within 1/16" or 1.3mm)

3.) Check chain alignment and see if you are going to have to change sprocket carrier or swingarm to get chain alignment (to within 1/16" or 1.3mm).

If NOT go back to 1.) above.

Alignment between rear and front wheel is going to be a fine adjustment one the 3 items above are sorted.


BTW, to get to these accuricies with a tape measure you need to "burn and inch"

A.) Do you have any idea what your rear spacers needs to be. The front alighment can be changed all over the map if the rear wheel is not centered in the frame. Wheel offset in the swing arm is based on swing arm offset. The wheel needs to be in the center of the frame (+/- 1/8" if you are going to use a tape measure).

B.) Did you see if the rear wheel is aligned with the swing arm pivot? Measure distance between rear axles and the swingarm pivots.

Ok good, I'll double check those things. I assume the rear wheel is centered as the swing arm and wheel come form the same donnor bike (GSXR 750 1991) and I have all the original parts on it. THks

[posplayr]

I posted in this thread a while back

http://www.thegsresources.com/_forum/showthread.php?p=1102275#post1102275