Announcement

Collapse
No announcement yet.

81 GS650E Sprocket sizes

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    81 GS650E Sprocket sizes

    Hi all,

    Ive an 81 GS650e with 15 tooth front and 45 rear. RPM seem to be way too high, even when doing 80km/h.

    What size are others with this particular bike running? I understand that 15/44 is standard for this although the 45 is an option also. I’m happy to lose low down acceleration etc to be able to cruise a little faster, enabling me to go on longer open road type rides.

    I’ve done plenty of searches but would like to hear what other combo’s you’re running on the 650.

    Cheers
    81 GS650e

    #2
    You might want to try a 16 in front. That will make a noticeable difference and it's a cheap swap.
    Ed

    To measure is to know.

    Mikuni O-ring Kits For Sale...https://www.thegsresources.com/_foru...ts#post1703182

    Top Newbie Mistakes thread...http://www.thegsresources.com/_forum...d.php?t=171846

    Carb rebuild tutorial...https://gsarchive.bwringer.com/mtsac...d_Tutorial.pdf

    KZ750E Rebuild Thread...http://www.thegsresources.com/_forum...0-Resurrection

    Comment


      #3
      Thanks for the response. I’m thinking i’ll Give something like that a go. I’m amazed that the top end cruising speed is so limited based on factory specs.

      cheers
      81 GS650e

      Comment


        #4
        One other thing to consider.

        What is your engine speed at 80 km/h?

        What would you like it to be?

        What other engine(s) are you used to?

        Many who are 'new' to smaller-engined bikes are not accustomed to the RPM that they need to run properly and want to slow the engine down. One problem is that slowing the engine will bring it down, well out of its power band. When it gets out of the power band, you will have to open the throttle more to compensate, which will really start sucking gas.

        My son had a 650L (shaft-driven). If I remember correctly, engine speed was about 6k at 70 MPH (110 KPH). Fuel economy was decent, in spite of the pods and pipe. Can't say that the engine ever sounded like it was running too fast at those speeds.

        .
        sigpic
        mine: 2000 Honda GoldWing GL1500SE and 1980 GS850G'K' "Junior"
        hers: 1982 GS850GL - "Angel" and 1969 Suzuki T250 Scrambler
        #1 son: 1986 Yamaha Venture Royale 1300 and 1982 GS650GL "Rat Bagger"
        #2 son: 1980 GS1000G
        Family Portrait
        Siblings and Spouses
        Mom's first ride
        Want a copy of my valve adjust spreadsheet for your 2-valve per cylinder engine? Send me an e-mail request (not a PM)
        (Click on my username in the upper-left corner for e-mail info.)

        Comment


          #5
          Thanks Steve,

          I believe mine might be in the order of 5500rpm or so at only 80km/h but i’ll take it for a run soon and confirm the RPM etc.

          Mine certainly seems to be excessively high given the low speed.

          cheers
          81 GS650e

          Comment


            #6
            Ok, took it for a run and it sits on 4050-4100RPM at 80km/h. Seems to cruise along ok. Maybe 1 tooth larger on the front to allow ,e to cruise a little faster at similar RPM?
            81 GS650e

            Comment


              #7
              Originally posted by Gs650eAUS View Post
              Ok, took it for a run and it sits on 4050-4100RPM at 80km/h. Seems to cruise along ok. Maybe 1 tooth larger on the front to allow ,e to cruise a little faster at similar RPM?
              Rev it and love it!

              BTW, do the 650s use a 630 chain? If so, downsize to a 530 or 520, along with suitable sprockets.
              Cheers, Andy

              Current bikes... 78 GS750E, 72 CB500K1
              Previously owned...
              01 VFR800Fi, 67 Honda Sports 90
              71 Yamaha 175 CT2, 73 Yamaha RD250 (great bike!), 79 Yamaha XT250T
              75 Kawasaki KX125 (little screamer!)
              BMW R65, BMW R80, BMW R100LT

              Comment


                #8
                Originally posted by Gs650eAUS View Post
                Ok, took it for a run and it sits on 4050-4100RPM at 80km/h. Seems to cruise along ok. Maybe 1 tooth larger on the front to allow ,e to cruise a little faster at similar RPM?
                I wouldn't....Just run it at a higher rev. You won't hurt nuthin'...

                Heck...what's the redline on that thing? 9500 rpm or something? Peak torque around 8K probably?

                4K is just loafin'

                You can run 7-8K all day on that bike....
                Bob T. ~~ Play the GSR weekly photo game: Pic of Week Game
                '83 GS1100E ~ '24 Triumph Speed 400 ~ '01 TRIUMPH TT600 ~ '67 HONDA CUB

                Comment


                  #9
                  Hi Andy,

                  Thats the plan! Haha. Did 100km today and she loved every second of it.

                  This one has a 530. I’ll do some more research but perhaps one larger on the front.

                  Cheers
                  81 GS650e

                  Comment


                    #10
                    Thanks Bob,

                    I see where you’re coming from but I thought it would be better if I wasn’t riding it too hard all the time.

                    Cheers
                    81 GS650e

                    Comment


                      #11
                      Originally posted by Gs650eAUS View Post
                      Thanks Bob,

                      I see where you’re coming from but I thought it would be better if I wasn’t riding it too hard all the time.

                      Cheers
                      Guess that depends on what you mean by "better"

                      It is probably "better" for the bike to run near peak torque, but others who know more can verify that.

                      I'd at least try it stock for a while...Easy to change later.
                      Bob T. ~~ Play the GSR weekly photo game: Pic of Week Game
                      '83 GS1100E ~ '24 Triumph Speed 400 ~ '01 TRIUMPH TT600 ~ '67 HONDA CUB

                      Comment


                        #12
                        Originally posted by Gs650eAUS View Post
                        ... I thought it would be better if I wasn’t riding it too hard all the time.
                        Actually, running it faster at a lighter throttle setting is better than lower speeds with open throttle.

                        .
                        sigpic
                        mine: 2000 Honda GoldWing GL1500SE and 1980 GS850G'K' "Junior"
                        hers: 1982 GS850GL - "Angel" and 1969 Suzuki T250 Scrambler
                        #1 son: 1986 Yamaha Venture Royale 1300 and 1982 GS650GL "Rat Bagger"
                        #2 son: 1980 GS1000G
                        Family Portrait
                        Siblings and Spouses
                        Mom's first ride
                        Want a copy of my valve adjust spreadsheet for your 2-valve per cylinder engine? Send me an e-mail request (not a PM)
                        (Click on my username in the upper-left corner for e-mail info.)

                        Comment


                          #13
                          I think I get what you mean although it’s not running faster at a lighter throttle setting, I’d be giving it a fist full if I were to be able to cruise at 90-100km/h. Or am I confused? Haha
                          81 GS650e

                          Comment


                            #14
                            I think he's saying 3000rpm at 75% throttle with lower gearing is harder on the bike than 6000rpm at 50% throttle with stock gearing.

                            I agree.
                            Jordan

                            1977 Suzuki GS750 (My first bike)
                            2000 Kawasaki ZRX1100
                            1973 BMW R75/5

                            Comment


                              #15
                              Buddy of mine has a GSX1100F, powerful bike.

                              He tried going up 2 teeth on the front sprocket and had to cut off a support
                              off the sprocket cover to make it work.
                              This powerful bike would not go past 190 km/h. (standard easy over 220)
                              Guzzling gas too.

                              So back to 1 tooth over standard. That did lower the revs at cruising speed
                              between 120-150 km/h, but still using way more gas.

                              He's back at standard gearing.

                              The GS650 is not as powerful as that, and will probably suffer more noticable.
                              Rijk

                              Top 10 Newbie Mistakes thread

                              CV Carb rebuild tutorial
                              VM Carb rebuild tutorial
                              Bikecliff's website
                              The Stator Papers

                              "The thing about freedom - it's never free"

                              Comment

                              Working...
                              X