Following threads in the past, I ordered
1  JT countershaft 16T stock-sized sprocket     $ 7.88   part no. JTF565-16-PU

It's the same as the one that came off the bike ... except it doesn't have a lip... so it's not as thick as the stock one...

the C clip is the only thing holding it on the bike, and when the C clip goes into the groove, the sprocket can slide back and forth on the shaft...

what's going on?

ok, after doing some more research, it looks like after 1993 they started using different sprockets.

I have a 1999.

going by this:
http://www.bbburma.net/Documents/GS500_Chains&Sprockets.txt

I actually need the JTF512 ... which has the "shoulder" on it.

so I'm going to return this one.  The stock sprocket as 16 teeth, is it beneficial to go to 15 teeth?  will the chain size or rear sprocket change if I do this?

I think It's better to go with a lower gear ratio, noticed better ecceleration and high top speed. with one tooth I'm not sure about the chain size but I've got a 13 or 14 and had to go 108 link to fit properly. You don't need to change the rear teeth, but I change them all at the same time. Next time I will go 15t up front and bigger on the back, as people say that small of a front will wear your chain faster.

I just went back to regular gearing my bike last week after having one tooth down on the front for the past two years.

I did like the "better" acceleration on the low end, but I got sick of constantly gear changing, and seeing the tach dance around 8,000 rpm on the highways all the time. I was going through more oil than usual because of the valve float at that rpm, and the gas mileage sucked balls.

Thanks, I'll elect to have stock gearing, see 7,000 rpm at highway speeds and enjoy 40km/25 miles more on the tank before hitting reserve.

GSJack claims that you don't need the "hub" for the later models, that it self-aligns. He has the experience to back it up.

A couple washers could work too 

Yes 94' and later used a sprocket with a hub to allow for chain allignment. I would recommend getting one with it if your bike came with it.

so is the JTF512 the correct sprocket for my bike?

Quote from: Wrecent_Wryder on June 12, 2007, 03:09:56 PM
GSJack claims that you don't need the "hub" for the later models, that it self-aligns. He has the experience to back it up.

Quote from: mattress on June 13, 2007, 09:31:46 AM
so is the JTF512 the correct sprocket for my bike?

No, the JTF516 is the correct sprocket for 94 and later GSs with the hub on the sprocket.   But, the JT565 w/o hub can be used on all 89 and later GSs as can the Sprocket Specialists 504 spocket.

I put 4 replacement chains on my 97 GS500 and got a new SS 504 15T sprocket with the last three, all from Chaparral with a DID 0-ring chain and clip type link.  When I got the first SS sprocket from Chaparral, I e-mailed SS about the no hub on the sprocket, they listed the 504 for all years.  SS replied that the hubless sprocket would indeed work on all years and that the "floating" front sprocket aligned itself from the fixed rear sprocket and indeed it did.  Every time I looked at one of those hubless sprockets with the cover off it was right up against the C clip and stayed there.  If your rear wheel is aligned properly it is a waste of time and washers to put something behind the sprocket.

I put a DID 0-chain and sprocket on my 02 GS and used the SS 504 16T front sprocket.  When it came time to replace the chain again I noticed the sprocket was a bit looser on the output shaft and also that the rear wheel was a bit out of alignment causing the wear in the sprocket bore, the shaft showed no wear from the misalignment.  I had already ordered a chain from Chaparral so I just picked up a OEM sprocket from local dealer.  I would still use either the one with the hub or the one without the hub in the future.

I've never replaced a rear sprocket in 120k GS500 miles and a total of 350k mc miles.