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Changing the Rear sprocket ratio

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    Changing the Rear sprocket ratio

    I am exploring changing the rear sprocket on the GS for a smaller one. The current sprocket is a 44, I have two choices I am looking at. One is a 40 the other is a 38.
    Now I was looking at my sprocket choices and that my bike seems to share its sprockets with these bikes,
    GS750E 80-83
    GS750ES 83-86
    GS750EF 84-85
    GS750S 84-86
    GSX-R750 90-95

    So I was thinking, hopefully correctly that any rear that will fit those bikes will fit mine, right?

    Chatting with a few riders, they figure that I should go with the 40 rather than the 38. Their primary reason is that I will loose accelleration off the line. My main goal is to reduce cruising rpm. It will only cost me $28 bucks for a new rear sprocket, so I guess I will try the 40 first, to see what happens.

    Anybody have thoughts about the 40 as the way to go?

    #2
    for 28 bucks suck it & see... one persons opinion is never the same as another in cases such as this in my experience.
    I know people who will swear on a different final drive ratio to me on a kit car, even though they are pretty much the same car.

    Dan
    1980 GS1000G - Sold
    1978 GS1000E - Finished!
    1980 GS550E - Fixed & given to a friend
    1983 GS750ES Special - Sold
    2009 KLR 650 - Sold - gone to TX!
    1982 GS1100G - Rebuilt and finished. - Sold
    2009 TE610 - Dual Sporting around dreaming of Dakar..... - FOR SALE!

    www.parasiticsanalytics.com

    TWINPOT BRAKE UPGRADE LINKY: http://www.thegsresources.com/_forum...e-on-78-Skunk/

    Comment


      #3
      A 44 to a 40 seems a little drastic. Please let us know what you did and how it worked out. THANKS!!!

      Comment


        #4
        I wouldn't drop more than two or you'll be dragging the clutch big time on take off.
        1983 GS 1100E w/ 1230 kit, .340 lift Web Cams, Ape heavy duty valve springs, 83 1100 head with 1.5mm oversized SS intake valves, 1150 crank, Vance and Hines 1150 SuperHub, Star Racing high volume oil pump gears, 36mm carebs Dynojet stage 3 jet kit, Posplayr's SSPB, Progressive rear shocks and fork springs, Dyna 2000, Dynatek green coils and Vance & Hines 4-1 exhaust.
        1985 GS1150ES stock with 85 Red E bodywork.

        Comment


          #5
          As a rule, 1 tooth on the front = appx. 3 on the rear + 1 up in front is more healthy for the chain, cause the chain doesn't need to bend as tight to go around a larger sprocket. If someone sneeked couple of teeth off the rear, you may not even notice, 4 teeth & you will notice, but not real drastic.
          1983 GS1100E, 1983 CB1100F, 1991 GSX1100G, 1996 Kaw. ZL600 Eliminator, 1999 Bandit 1200S, 2005 Bandit 1200S, 2000 Kaw. ZRX 1100

          Comment


            #6
            Alternatively, you could go up 1 tooth on the front sprocket...may be cheaper, easier, and IIRC 1 tooth on the front alters the ratio the same as 3 on the rear...I'm not sure what size front the stock 750 runs. Check out the chain/sprocket section at z1enterprises.com...a lot of good gearing info there, will enable you to calculate your rpm drop with different ratios.

            Tony.

            EDIT....Philips beat me to it
            '82 GS1100E



            Comment


              #7
              dropping 6 teeth is a big jump, and a rather significant change in the final ratio. I would go with the 40.

              as other has said, add a tooth the front is better.
              AND
              while you are in there, be sure to inspect your chain and front sprocket as well. if the stages of wear are very different front to back, and the chain is stretched at all, then you could have some pretty fast wear and tear on your hands by adding a new rear sprocket.

              Comment


                #8
                Better to replace all chain & sprockets in set if possible if you're going to do it...

                Dan
                1980 GS1000G - Sold
                1978 GS1000E - Finished!
                1980 GS550E - Fixed & given to a friend
                1983 GS750ES Special - Sold
                2009 KLR 650 - Sold - gone to TX!
                1982 GS1100G - Rebuilt and finished. - Sold
                2009 TE610 - Dual Sporting around dreaming of Dakar..... - FOR SALE!

                www.parasiticsanalytics.com

                TWINPOT BRAKE UPGRADE LINKY: http://www.thegsresources.com/_forum...e-on-78-Skunk/

                Comment

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