Welcome to Netrider ... Connecting Riders!

Interested in talking motorbikes with a terrific community of riders?
Signup (it's quick and free) to join the discussions and access the full suite of tools and information that Netrider has to offer.

Tyre Pressures (PSI)

Discussion in 'Scooters' started by mr_sikma, May 30, 2006.

  1. Hey,

    I have a 2005 Bolwell Jolie 50cc.

    I am just curious as to what people believe to be the right amount of air should be in the tyres?

    My handbook is in some weird measurement with kgs per soemthing etc

    I also read somewhere that the pressures should be checked every 3-4 times you fill up, so about every 500kms or so.

    As i havent done alot of kms in my skoot so far (1900kms) i havent really checked it, apart from servicing.

    Today they were around the 15psi mark and according the placard on the BP air pumps they recommend 30psi for 'motor scooters'.

    I put 30psi and felt it was a bit harder and the tyres feel to roll smoother, but i didnt notice alot of difference in handling, etc.

    What can having too low or too high tyre pressures cause?


  2. Better a little higher rather than too low.
    Too low will cause heat build up and ultimately damage the tyre.
    Higher will give you a firmer ride (like a car) .

    15psi is way too low and could cause handling and braking problems.
  3. Go with the manual!

    The Jolie is 150 kPa (1.5 kg/cm^3) up front
    and 220 kPa on the back.
    Since you are still working in Pounds, shillings and pence -
    that translates to 22 psi and 33 psi respectively.

    When a tyre is underinflated the pressure is on the sides of the tyres instead of being even across it. This causes the tyre to flex and lose grip on turns. It also wears the tyre quicker and you will need to replace it much sooner. If it is too low the tyre will generate too much heat and could even blow.

    When it is over inflated, it rides on the centre tread only and that gives you less contact with the road giving you less grip and a harsh ride.

    Motorcycles are much more prone to problems from incorrect tyre pressures than cars.

    Always check pressure on a cold tyre and theory says before every ride.
    You can probably get away with checking it once a month.

    You should have noticed a LOT of difference in handling once the pressures where back up.
  4. I'm a big guy on a Bolwell Gypsy. I put 30psi in the back and 26 in the front.
  5. thanks guys

    i am a tad younger so the old measurements dont mean too much too me!

    so i mite drop the front down a bit and put a bit more in the rear!

    so why does it drop so regular?

    also i havent tried to corner harder as i thought it maybe worse with more air in!

    will check the pressures again 2mrw and let yas know ;)

    BRADDO... Check your yahoo email! also do you still run the standard tyres in your jolie?
  6. '

    Kpa (kilopascal) is metric and psi ( pound per square inch) is imperial as you state you are young so you would be more likely to use kpa nevertheless a lot of people still use psi.

    Tyres lose pressure over time because rubber is actually slightly porous, thus tyres inherently lose pressure over time.

    You shouldnt have to inflate them every day if you do its possible you may have a puncture.

    I check mine about once a week, I find this sufficient.

    As Braddo said, best stick with the pressures indicated in your manual. Make sure you do it when they are cold.
  7. cold tire pressure

    this is going to sound silly.. but how do you fill them cold, if your local petrol station is about 2km's away??

    or do you mean, relatively cold??

    I have a TGB Akros-tec, and prefer a firmer tire, so I am filling up to 38psi oncer per month or so. Most of the time it needs no adjustment
  8. yeah as soon as possible after first riding i reckon.

    from my understanding the tyres would hit their hot operating temps very soon after first riding.
  9. shouldn't be tood bad after 2km's then..

    I wonder how quick they cool down after a ride?
  10. Re: cold tire pressure

    Get a compressor.
  11. Depends on the tyre as to the warm-up time, so i have no idea for scooter tyres.
    Mine will be up to standard riding pressure after about 3km's @ 60km/h. They'll be up to enthusiastic riding pressure after about 5km's @ 100 (or so) km/h.

    As silly as it sounds, i actually carry a small bicycle pump in my bike in case of emergency's. I had a bad run with picking up sharp objects in my rear tyre. :cry:

    My little single action bicycle pump will happily take my rear tyre up to 42psi with a bit of effort, so i'm sure it'll take make a quick job of smaller scooter tyres.
  12. KG/some metric area should look similar to kpa. just a factor of 10 of 100 or something out.

    As to intervals it depends on what type of riding you do.

    I filter, ride in service lanes, good roads, shit road and then get on the expressway. each way. every day. so my tyres can pick up all sorts of shit.

    As such I try to check every fuel stop. Generally this turns out to be every second, but I try.
  13. Another check to determine whether your tyre pressure is correct is the following: Note the 'cold' pressure of your tyres, then after one hours use, note the pressure of the 'hot' tyre. If the pressure has increased by 28 KPA (4 PSI) you have started with the correct pressure. If the pressure has increased by more than 28 KPA (4 PSI) then the starting pressure was too low.
  14. I already have a pressure guage/tester.. but a compressor sounds the go, as the ones at the petrols stations are usually crap
  15. my old bolwell euro used to like around 30 in the rear tire and 28 in the front.

    All tyres are different but I used to top them up every couple of weeks. a compressor at home is priceless but just make sure you have a good quality gauge
  16. well i put 30 in each a week ago but after riding for a while...

    i had 26psi in the front

    and 27psi in the rear

    now running 28 up front
    and 33 on the rear
  17. will do, ta! :wink:
  18. I use a push bike hand pump for my scooter tyres. The tyres are that small that im sure it would only take a couple of minutes to pump a dead flat scooter or bike tyre up within a couple of minutes. All you need is a seperate tyre pressure guage, and you can check the tyre pressure dead cold before you ride it.
  19. got both those, but I was also looking at the car.. so I want a better quality gauge rhather than the crap pencil one I currently have, and then a compressor, as the Falcon tires would take forever with a hand pump...

    I went down to Repco, and priced a good gauge at $10, and a DC powered compressor for $7!! Not bad! :shock: