New to changing sprockets

[Madmike]

Hey guys I just ordered a new front and rear sprocket for my recently acquired (OLD USED) 1989 GS500E . The dealer told me all I could get was a 14tooth not a 15 tooth. So what is this gonna do for me? I think I'm getting the stock is it a 39 tooth???

Just curious dropping that tooth in the front / whats it gonna do? I have a 520 O-Ring chain coming in for it too...

Hope it does good things...

Mike

[dgyver]

Your dealer is incorrect. 15T sprockets are readily available. Plenty have changed to a 15 and some try a 14. The chain gets tight with a 14T. There have been several threads regarding this.

Personally I like 15/41 for the street. 

[mattress]

welcome to the wonderful world of the GS500!

I too am a new member here, I acquired my '99 a few months ago, and have loved every moment of riding!

Anyway, to answer your question about the teeth.  I think the general rule of thumb is if you drop a tooth up front, you go up 2 teeth in the back.  
This will give you more low-end power..faster pickup... but your engine will be running faster at highway/cruising speeds, and will have a lower top-speed.

some people don't like that trade-off.. myself included..  I just ordered a stock-teeth sprocket + chain set from parts411.com ... still waiting for it to come in the mail!

[Madmike]

Just confirmed with the dealer that the front sprocket ordered is a 15 - the 89 came with a 16 tooth stock (weird) - anyhow my gear ratio is 15/39 so 39 tooth for the rear. Whats this gonna do for me?

Thanks

Mike

[Chuck]

All years have a stock 16T sprocket.  The math is simple.  15 is about 6% less than 16, so your RPMs will be about 6% higher at a given speed and you'll have 6% more torque.  Your top speed is theoretically reduced by 6%.  Although since the GS's top speed is limited by torque far before the theoretical top speed, the top speed isn't really changed in any way.