Home Forums Tech Talk gear ratio /tm k9c

This topic contains 3 replies, has 4 voices, and was last updated by  Richard Kirlin 4 years, 5 months ago.

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  • #39790

    Just purchased a tm k9c,  I plan on running open 125. The track is 2.2mile 9turns the main straight is a 1/4 mile drag strip. I plan on running a 50mm axle, can anyone give me a good gear ratio for that long of a straight

  • #39794

    Glenn L Riggs

    I would try a 18/21 as a starting point

  • #40398

    Antonino Esposito


    I’m a italian boy and I’m sorry for my english!!!

    Anyway, also I have a tm k9c, it’s very good engine!!! The track with  the main straight of 1/4 mile It’s very long. I think that a good starting point to gear ratio is 19×22 !

    At 13800 rpm your final speed will be 170 Km/h

  • #41456

    Richard Kirlin

    I’ve raced TM motors on big road course,  a 19/21-22,  18/21-22 will work depending  on weight and hight of the person?


    best of luck:)



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