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How to work out Tyre Pressure

Discussion in 'Bling and Appearance' started by Black Betty, Aug 5, 2005.

  1. Am tired of getting different answers at every servo - so need the EXPERTS please.
    How do I convert the manuals/bikes figures to PSI?

    Front is 2.00kgf/cm2
    Rear is 2.25kgf/cm2

    Took a guess at a digital one today - but felt like I was bouncing all the way home - or maybe I'd been riding on underflated to start with....

    Your Advice Will Be Greatly Appreciated :D
  2. that's a search using google if ever i saw one dude :) just type in the measurement and the words convert to psi and you'll be in business
  3. Try Google.
  4. Two Google's in one go! :)

    Also remember to buy yourself a decent gage and take the readings when the tyres are cold.

    My manual has the figures in PSI which helps, no sure what's up with yours.

    I just go to the servo and wack extra air in, then ride home, wait till it cools and release the pressure to the correct amount.
  5. To convert BAR to PSI multiply by 14.5 - e.g. 2.0BAR * 14.5 = 29PSI

    To convert KpA to BAR divide by 100 - e.g. 200KpA / 100 = 2.0 BAR.

    To convert Kpa to PSI multiply by 0.145 - e.g. 200Kpa * 0.145 = 29PSI

    This still isn't helping - its kgf/cm to PSI????
  6. As a rule I run cold pressures as follows;
    Rear 42psi
    Front 36psi
    I have found over most of my bikes that those pressures work well.
  7. Thanks - that was a recommendation on another forum (for someone who asked the same question) for a triumph.
    Trouble is by time I've gotten to servo tyres are warm. Did them 29 front 33 back and that seemed high?
    Am still searching google for the equation...
  8. FOUND IT!! :D

    2.00kgf/sq cm = 28.44669 (ie 28PSI)
    2.25kgf/sq cm = 32.00252 (ie 32PSI)

    So I was close guessing (now need to do it with cold tyres)

    :p :D :p
  9. Equation is -

    kgf/sq cm X 14.22 = PSI

    now back to real work ....
  10. not sure on what bike you have :?:
    If a 250 then 36 rear and 32 front. If a bigger bike then the above recommendations :!:
    If you haven't got a tyre pressure gauge get one but not a cheap one. I use a Michelin which race teams use and works really well and very accurate.
    If you have a gauge then pump tyres up to 45 - 28 respectively and in the morning reduce pressures to the correct pressure.
    Don't be concerned if the pressure seems high. When I get new tyres I always get my mechanic to put the pressures up to 50 psi as it helps the bead set and then reduce the pressure the next morning. I no longer lose pressure from my tyres.
  11. And, as an addition to that, put in about 4 pounds more in each tyre if you're doing long trips.
    Drop it back if you're commuting a lot.
    Servo pressure gauges are notoriously unreliable so marty's suggestion about buying one of your own is very good advice.
  12. Also put another 20 pounds in if you have a really overweight pillion.
  13. in my manual, it says 29 each for a VTR 250 for the tyre pressure
  14. Thanks - apart from the overweight pillion bit(!) for the good advice. Have had a look in KMart but couldn't find a decent one.

    And thanks Dan - you ALWAYS seem to have the right answer!?!
  15. Try a bike shop, I got a decent Michelin one from Peter Steven's in the city.
  16. Interesting - my manual specifies different for front and rear (same with or without pillion)?

    Its a 2002 VTR250