I own a 93 with the narrow/shoulderless front sprocket. Now I was looking at the fiche and got thinking (dangerous, I know!).

http://wiki.gstwins.com/index.php?n=Main.GearBox

I know that the c clip is the outbound restriction on the sprocket thickness but is part 37 the inboard restriction or is it the depth of the splines on the shaft, part 15?  If it is part 37, can it be removed without splitting the cases? I was wondering if it could be milled or replaced with a newer version to get the clearance to use a shouldered front sprocket.

Out of curiousity, why would you want to? It doesn't make a difference, and both are available....

but to answer the question, 37 is a spacer, and yes, theoretically could be turned down, but for all the trouble...again, why?

My front sprocket has some movement which may be normal with only 24 thou, but if it was easy enough I wanted to change to the shouldered style front sprocket. Its mostly for peace of mind because I wouldn't mind the better wear characteristics of the thicker gear.

Bear in mind, the gear itself is no thicker. So there is no real difference in the life. THat is more down to the quality of the part. The thickness doesn't change the lifespan of it. The extra thickness, is simple to take up space. Remove that spacer shoulder on the newer style, and it's just the same exact one we already have. If you have play in the sprocket, and .024, is nothing, then it may just be time to replace the sprocket. For the $12 you spend to replace it, you'd spend countless more hours taking the whole thing apart to convert it to use basically the same $12 part.

Now, if you are getting excessive play in the shaft itself...you may need to look into that.

sorry i meant 24 tousand miles, thanks for the info. I was under the impression that the later model year gs has a thicker gear to give more mating surface area between the gear and the splined shaft in an effort to prevent poblems like this...

http://gstwins.com/gsboard/index.php?topic=57392.20 

Can't say much for that really, but it's possible. I have not seen anyone swap them that I can remember. Despite the age of mine, it's only turning over about 19K this year...with no real visible wear on that spline. I think how you ride has a lot to do with that. The thin sprocket was standard up until the 01 changes I think...so can't be that bad. A lot has to do with making sure everything is aligned properly as well.

Quote from: X-ray on November 27, 2013, 02:46:37 PM
My front sprocket has some movement which may be normal with only 24 thou, but if it was easy enough I wanted to change to the shouldered style front sprocket. Its mostly for peace of mind because I wouldn't mind the better wear characteristics of the thicker gear.

All front sprockets wiggle. Some more than others.t is OK and that's what they do.
The sprocket and splines last longer if greased. Otherwise they can rust and rust wears down faster than greased steel.

Unless the splines are seriously damaged from abuse, you are OK.

I understand what it is your are trying to achieve. Yes its possible but its not going to be easy.

Suzuki put that boss on the sprocket to increase the contact area of the splined surfaces in an attempt to reduce wear. In order to accommodate the increased length the spacer the sprocket sits up against had to be shortened.

The original sprocket is about 5.75mm thick and the modified one including the boss is about 8.5mm, a difference of about 2.75 so it stands to reason the later spacer will be 2.75mm shorter along its length than the original.

The spacer can be faced off easily enough in a lathe but the problem will be in getting it off the shaft to do this while its in situ. The spacer will be an interference fit and reasonably tight....2 reasons why:

1) If it was loose there would be a leak path between the inside of the spacer and the shaft and oil would bypass the seal and drain out
2) The seal runs on it and if it was loose the seal might hold it and prevent it from turning with the shaft. It could remain stationary and lead to wear on the inside and on the shaft.

It will need to be pressed or drawn off, very difficult with the shaft still in the case. If you did decide to go ahead it would be easier just to swap the older spacer for the newer one.......once the old one is off 

Original spacer # 27531-01D00
modified spacer # 27531-01D10

The important thing is to keep those splines lubricated with grease, particularly on the older ones that don't have the boss on the sprocket. That red dust you see on dry splines is fretting corrosion. Its microscopic particles of steel that have been `hammered` off the splines when the surfaces contact which has then rusted when the moisture in the atmosphere hits it. Grease or `copper-slip` goes some way in preventing this happening.

Quote from: sledge on November 28, 2013, 03:42:00 AM

The original sprocket is about 5.75mm thick and the modified one including the boss is about 8.5mm, a difference of about 2.75 so it stands to reason the later spacer will be 2.75mm shorter along its length than the original.

The spacer can be faced off easily enough in a lathe but the problem will be in getting it off the shaft to do this while its in situ. The spacer will be an interference fit and reasonably tight....2 reasons why:

1) If it was loose there would be a leak path between the inside of the spacer and the shaft and oil would bypass the seal and drain out
2) The seal runs on it and if it was loose the seal might hold it and prevent it from turning with the shaft. It could remain stationary and lead to wear on the inside and on the shaft.

It will need to be pressed or drawn off, very difficult with the shaft still in the case. If you did decide to go ahead it would be easier just to swap the older spacer for the newer one.......once the old one is off 

Original spacer # 27531-01D00
modified spacer # 27531-01D10

Thank you. This is the information I was looking for. I wasn't aware that the spacer was an interference fit from the fiche alone. The measurements and part #s will be very useful should I decide to pursue this.

My original line of thinking was that, albeit minor, this was an up grade and if simple enough, why not do it. It bugs me sometimes the way some things are designed especially when a minor improvement can change things for the better regarding longevity, reliability, and safety.