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    Question on tire conversion sizing

    I will need new tires on my GS300, but I can't seem to find an exact match. According to my owners manual the front is a 3.60S-18 4PR and the rear is a 4.60S-16 4PR. The front looks like a 100/90 is too small and a 110/90 is too big. The rear looks like either a 110/90 or a 120/90 would both work. I don't think the correct tire is on the front because the speedometer reads slower than I am actually going.

    What size would you guys use? Or should I look for an exact match? Thanks!

    #2
    It is rather unusual to have the speedo reading slow. I am lucky enough that my wife's 850L reads VERY close to correct.

    Tire size will make a difference on speedo readings. The 3.60 front tire translates to 91.44mm, so go with a 90/90. The smaller tire will rotate a bit quicker, making the speedo more accurate. The 4.60 rear tire translates to 116.84mm, so a 120 would probably be best.


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      #3
      Sweet thanks!

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        #4
        speedo

        Originally posted by Steve View Post
        It is rather unusual to have the speedo reading slow. I am lucky enough that my wife's 850L reads VERY close to correct.

        Tire size will make a difference on speedo readings. The 3.60 front tire translates to 91.44mm, so go with a 90/90. The smaller tire will rotate a bit quicker, making the speedo more accurate. The 4.60 rear tire translates to 116.84mm, so a 120 would probably be best.


        .
        Is there anything available to reduce mph numbers so that you can read past 85mph? Was thinking that something use to be available to cut numbers in half?( 80mph was reduced to 40mph) what ever you where reading just double it/ any help???

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          #5
          Originally posted by Geoff4130 View Post
          I will need new tires on my GS300, but I can't seem to find an exact match. According to my owners manual the front is a 3.60S-18 4PR and the rear is a 4.60S-16 4PR. The front looks like a 100/90 is too small and a 110/90 is too big. The rear looks like either a 110/90 or a 120/90 would both work. I don't think the correct tire is on the front because the speedometer reads slower than I am actually going.

          What size would you guys use? Or should I look for an exact match? Thanks!
          This might help. Its a conversion chart.

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            #6
            I believe your bike has a 1.85 front rim so you can run a 100 tire which has a fair bit more meat than a 90. The rear rim is 2.15 so you can run that 120 no problem. having the most rubber on the road as possible is generally a good thing.
            Ed

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              #7
              I'm getting a tire in that is a 130/90 as a replacement for a 4.60 It will be a little bit wider but if I remember right, only about 1/2 inch. Everyone I talked to about it said that it shouldn't be an issue. The rims are tubed type too so no worrying about sidewalls poping off the beads. I mistakenly clicked on the 'front' style tire when ordering though and I haven't totally figured out what I'm going to do about that. It's a pirelli mt66. Any suggestions about if I should send it back or not?

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