Building a vintage track bike

[Old Colt]

Just found this thread. Way back when these bikes were new I raced my '79 GS550. It was not stock.



These pics were taken a decade ago.
At the time I ran with both the stock swingarm and a short period with a GS750 swinger. Had shocks on stock mounts as well as lay down shocks. The longer swinger sucked, made the bike a slug. We tried a few different heights in the rear but the bike was far better on the original short swingarm which at that time I was welding braces onto.
Early on I ran the longer GS750 fork tubes to gain cornering clearance on the alternator case. Near the end it rode on GS 100 forks which it is on now. Later for sprint racing I removed the starter and stator. Interesting changes there was the bike became very lively with the reduced flywheel as well as the bike then weighed in at 380#.
During that period I rode my modified 550, stock 750 and later a stock 16V 750. My 550 was by far the fastest and most nimble of the three.

To me, I would not be afraid of the tiny bit shorter arm on your build.

[one_civic]

Thanks Mark, and nice Bike Colt. I'm not at home right now and can't remember how far off the sprocket alignment is, not too worried about that as my friend will just machine off whatever is needed to get the chain centred, I wonder if wider rear 4.5"-5"-5.5" 17" GSXR rims have a narrower rear sprocket carrier that would fit my 18" rim assuming they use the same Cush drive?

[Old Colt]

Keep in mind there are offset front sprockets should you want to move the chain outwards, they are 5 or 8mm or so.
I think you will run into width issues going much over 4.5" wide, I could be wrong but that is where I am looking at going with the refresh on my old 550. I have a set of 17s for my bike but do not recall what the sprocket carrier was from, quite a mix & match of parts off ebay to set it up and I have not put hands on the rims in years. My current intention is wire spoke rims, 18 front and 17 rear.

[mmattockx]

I wonder if wider rear 4.5"-5"-5.5" 17" GSXR rims have a narrower rear sprocket carrier that would fit my 18" rim assuming they use the same Cush drive?

I just did some digging on partzilla and it appears that Suzuki used the same cush drive sprocket carrier ('sprocket drum' in Suzuki speak) for a fair number of years from 1986 up into the 90's on a range of bikes. The part is #64611-17C01. In 1991 or so the big GSXR's switched to a new design, but the sprocket carrier is a different style. On the plus side, the cush rubbers have the same part number from 1986 through to some current models, so maybe you can tweak the newer style carrier to fit the older wheel?

The partzilla page on the older style carrier is: http://www.partzilla.com/parts/detai...611-17C01.html


Mark

[one_civic]

Thanks Mark, I'll have to wait till I get home to do some digging around on partszilla from my laptop, and measure up and take pics of the rear wheel

[odl777]

Nice Bike Old Colt! On the rear shocks it looks like you are using eye to eye clevis on the stock swing arm....did you have to do anything special to do this or did you just bolt it up like normal.

Thank you!

[Old Colt]

Nice Bike Old Colt! On the rear shocks it looks like you are using eye to eye clevis on the stock swing arm....did you have to do anything special to do this or did you just bolt it up like normal.

Thank you!

Those are stock mounts.
When the bike was new I originally went with alloy body Koni, they were far from impressive. Sure looked pretty though. I soon had the red body Fox shocks W/ remote reservoirs and all my riding was on them. The Fox's on it now have not been ridden, yet.

[GregT]

I just did some digging on partzilla and it appears that Suzuki used the same cush drive sprocket carrier ('sprocket drum' in Suzuki speak) for a fair number of years from 1986 up into the 90's on a range of bikes. The part is #64611-17C01. In 1991 or so the big GSXR's switched to a new design, but the sprocket carrier is a different style. On the plus side, the cush rubbers have the same part number from 1986 through to some current models, so maybe you can tweak the newer style carrier to fit the older wheel?

The partzilla page on the older style carrier is: http://www.partzilla.com/parts/detai...611-17C01.html


Mark

The major change AFAIK is they went to 6 bolt sprockets from 5 bolt. I've used a GS1000 cush in a late 4.5X17 GSXR wheel no probs.

[mmattockx]

The major change AFAIK is they went to 6 bolt sprockets from 5 bolt. I've used a GS1000 cush in a late 4.5X17 GSXR wheel no probs.

When did they change? All GS1000's, 1100E's and GSXR1100's use the same 6 bolt sprocket pattern according to JT Sprockets. Good news on the GS cush fitting into the 17" wheels.


Mark

[one_civic]

I know for sure the older Slabby and Slingshot GSXR 750-1100 rear sprockets are 5 bolt, at least that's what they are here in Canada,

So anyways I guess I was in such a rush to mount the rear wheel onto the bike before leaving for Toronto that I didn't space the rear wheel properly

After loosening the rear axle bolt I noticed that their was still a 10mm gap that I should have taken up with a spacer on the rotor side, I have now taken up the clearance and the rim is almost perfectly centred in the rear swing arm, all I need now is to get a rear caliper and bracket for the 240mm rear GSXR rotor and either a 530 or 520 chain.

Is there a big difference in un sprung weight and price between the two or should I just go with a 530?

thanks guys

[mmattockx]

I know for sure the older Slabby and Slingshot GSXR 750-1100 rear sprockets are 5 bolt, at least that's what they are here in Canada,

Well, look at that. I went back to JT's catalog and the 86-88 GSXR1100's are indeed a 5 bolt pattern and then Suzuki went back to the old 6 bolt pattern for the 89+ 1100 models. I guess I never looked at the early GSXR's close enough once I found that the 1127cc oil cooled motors and the 1074cc liquid cooled motors matched my 1100E. Doh.

On the chain I would probably go with the 530 just because it is so common and sprockets are easily available for it.


Mark

[one_civic]

So I laser lined my front drive sprocket to my rear sprocket carrier and I need to machine 1/2" or 12.7mm off the rear carrier and shim out my front sprocket 1/8" or 3mm to have proper chain alignment. The only thing that kind of worries me is that there will not be much material left on the rear sprocket carrier, so.... I'm thinking of only machining off 3/8" or 9.5mm and shimming the front to 1/4" or 6mm.

My question is, has anyone used a front drive 530 15t sprocket shimmed outward 6mm? Was there enough of the sprocket on the output shaft spline? Pics for clarity, lol




[IMG][/IMG]

[mmattockx]

My question is, has anyone used a front drive 530 15t sprocket shimmed outward 6mm? Was there enough of the sprocket on the output shaft spline?

The drag racers regularly use offset front sprockets, up to 5/8" offset. They are available in a number of offsets direct from stock, nothing custom or funky required.

For instance: http://www.dgchassis.net/Dragbike%20...-sprocket.aspx


Mark

[Old Colt]

Keep in mind the front sprocket is available with a dish to it allowing you to go out 6 or 8mm with no fuss.
The only thing about shimming out is making sure you maintain spline a thread engagement. Ducati uses the same spline and many models have a very wide hub. This wide hub could be offset machined as needed but then why bother when the offset sprocket is available.

[one_civic]

Yeah, that seems like a better option than machining the rear sprocket carrier, now what brand does everyone use for a 530 15t 5/8 offset front sprocket for their 8 valve 750's?