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lightweight riders & tyre pressures

Discussion in 'Technical and Troubleshooting Torque' started by micksing, May 10, 2013.

  1. ok heres a tyre question & I cant find it covered anywhere , I am 51kg with my riding gear on & ride a cb seven fifty, I am experimenting with suspension & tyre pressure setups, nobody can tell me a minimum pressure for my tyres & before you all say stick to hondas recommendations for this bike, the recommendations are usually for an 70- 120 kilo rider the same with tyre manafacturers , I am checking wear patterns atc, but it just sh*ts me that they all talk about overloadin & max weight etc. but what about us flyweights ????
    or should I just buy a scooter :-/

  2. Well, a rational approach based on absolutely no expert opinion could be to assume the pressure should vary proportional to total weight. So, if your bike weighs 200kg and the manufacturer's recommendations are based on an 80kg rider.
    Your total weight = 51 + 200 = 251kg
    'Design' total weight = 80 + 200 = 280kg
    Proportion = 251/280 = 0.90

    If I were you and believed the recommended tyre pressures were too high, I'd say you could justifiably ride at 90% of what they recommend. If the book says 30psi, ride at 27psi.

    Having said that, perhaps Honda (especially older designs) designs based on the typical Japanese rider, who I'm guessing is lighter than the average guy you see in Australia. Running marginally too high pressure (i.e. what the book says) will probably improve economy marginally.
    • Informative Informative x 1
  3. I'd use spec and base any adjustment on handling and wear.
    Many will go slightly above recommended so if you sit on spec you should be fine.
  4. #4 micksing, May 10, 2013
    Last edited: May 10, 2013
    thanks for the formula very helpfull :) as for economy I dont believe in" it" handling & performance always comes first ;-)
  5. thanks guy's I guess the one advantage is that fully loaded for a trip my maximum load ie: rider & luggage comes in at well under 100kg's ;-)
  6. have you thought about a career as a jockey?
  7. #7 micksing, May 10, 2013
    Last edited: May 10, 2013
    I'm 178cm or 5'11" tall lol & I cant be a moto gp rider because I'm not spanish
  8. and only 51 kg ....geeeeeeeeeez.
    • Agree Agree x 1
  9. yep a real beanpole lol
  10. wish i had your problem mate lol.. too skinny.

    do you eat?
  11. certainly eat & anything I want to & dont gain weight, I bet not too many people have to shave 3 inches off the seat of a cb seven fifty because it's too wide lol
  12. what really gets me is that we have Jenny Craig, Gloria Marshall,weight watchers etc. etc. what about poor bastards like me that want to gain weight,
  13. It's not an exact science. While theory is good and would help by making a great starting point. Usually manufactures specs are better tho.
    It's a feel thing. How do you like the bike to feel.
    Light and easy, good economy and wear ??? Then I would stick close to the spec psi. That way for you it would be a slightly high pressure and should make the bike feel light.

    Heavier more glued to the road feel is found by using a slightly lower pressure.
    If the rear is spinning up a bit, or skating. Then lower the pressure in the rear. Same if the front feels a little loose and skatey.
    And only drop by 2psi at a time. And it will take some time to get use to the new pressure and feel it.
    Also only do your pressures cold... and use the exact same gauge.
    • Like Like x 1
  14. Exact same problem with me. I am 177cm at 55kg. I have always been 55kg since high school lol.

    Edit: PS - I am an Asian though, its in my genes to be skinny haha
    • Like Like x 1