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1/4 mile at Luskville Dragway this saturday :)

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    1/4 mile at Luskville Dragway this saturday :)

    so my first ever in my life run,...

    16.03 seconds, 88mph.. ya, that sucked.

    but I got better over the next 5 runs, and my best:
    13.7seconds, 100.024mph...

    Here's where I need ya'll help
    I'm basicly in 3rd gear near redline (10,000rpm) as I fly by the finish line... I know I should have the bike dyno'd to get the peak torque rpm & HP rpm... but has anybody got any input on what a good shift point would be for 1/4 mile (in RPM)?

    I'll be honest, the Tach doesn't seem to be horribly accurate at those high RPMs & speeds, but I was able to glance down at it a few times...

    Also, if it were better to shift a bit earlier, do you think I'd gain anything by shifting into fourth?

    I checked in the service manual, and the only overdrive gear ratio is in 5th... so I'd still have some torque multiplication in 4th... not much albeit...

    I'm all jealous as a guy on a stock ZX12r w/ modified swingarm was running 9.6s @ 142+mph...

    TIA for the input

    #2
    You might want to drop a tooth on the front or go up a few teeth on the rear sprocket.

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      #3
      What were you riding? If it was in your post, I didn't see it.

      Comment


        #4
        1986 GS750es (1983 motor though)

        Originally posted by karl_ibsen
        What were you riding? If it was in your post, I didn't see it.
        hehe,... good point
        1986/83 GS750es

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          #5
          Originally posted by Billy Ricks
          You might want to drop a tooth on the front or go up a few teeth on the rear sprocket.
          I'm currently running a stock 43 teeth on the rear end... haven't checked the front end yet though...

          are there any real issues to deal with other than chain size?
          I'd ideally like to not have to switch chains for 1/4 mile days (by having a 43 for daily driving, and 48 or so for track day)...
          how about how many teeth can you go up before needing a bigger chain?

          thx

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            #6
            If you just drop 1 tooth on the front it will be equal to about 3 on the back. If anything you will have to tighten the chain a bit after replacing the drive sprocket.

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              #7
              Which GS are you riding?
              What model?


              Billy has good advice, drop one tooth, shift at about 9K, then let it wind out in 4/th.
              Keith
              -------------------------------------------
              1980 GS1000S, blue and white
              2015Triumph Trophy SE

              Ever notice you never see a motorcycle parked in front of a psychiatrist office?

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                #8
                I think peak hp for the 750 is around 9500, so shifting a little after that is good. Pretty much shift at 10k. Ideally you want to cross the line at redline in 5th gear. Obviously that would be a big change gearing wise. When I had my 700 I was going to change my sprockets to a 15/50 I believe, giving me about the same gear ratio for the street, but giving me the ability to drop 2 teeth up front for the strip. I sold the bike before I got around to it though.

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