YZF R125 Sprocket Gearing Table Ratio

Discussion in 'Technical Discussions' started by diasilman, Sep 26, 2009.

  1. What are your current front and rear sprockets size (their number of teeth)?
    What is your current top speed?
    What size of sprocket you're going to use?

  2. stock sprockets
    133 km/h at 10500 rpm
    14 - 46 or 47

  3. by assuming the engine can be pushed to the same 10.500 rpm on 6th gear:

    -With 14 - 46 sprocket, you'll get 138-139km/h top speed

    -With 14 - 47 sprocket, you'll get 135-136km/h top speed.

  4. Hmm, great. Thanks! ;)

  5. I calculated those with this method:
    Current top speed multiplied by current sprocket ratio, then the result was divided by the new (planned to be used) sprocket ratio.
    nickda likes this.

  6. i know this is a really old post, but maybe i can reignite it? i'm kinda getting bored of my r125 now, it's a 58 reg, and i top out at like 84, which is the supposed standard max speed of the bike, so what do i need to do to get some power? like a complete list of modifications... i.e exhaust, gearing ratios, cylinder kits, cams, sprockets, air filters, power commanders, spark plugs, tyre sizes... ect....?:D

  7. Just buy a 250cc motorbike...

  8. This doesn't help at all... i do not have a full license and therefore could not insure a larger motorcycle.

  9. Me neither but I can legally drive 250cc bike...

  10. not in the uk you can... you need to have your full license.....

  11. Ok then, I understand

  12. Hello All,

    I am looking for a front gear 12, i cant find one in the shops for a YZF R125.
    I is for the CUP racer.

    Thank you for reading

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