different tire pressure readings???

7 replies to this topic
  • bigwake

Posted August 25, 2007 - 02:34 PM


my 03 yz450f tire pressure reads at 15 psi..with the same guage my buddy's 03 kx250 reads 5 psi..in both tires..i don't understand why this happens..when i sit on my bike..i can see the tires flex because i had them at 10 psi before..my friend's bike's tires don't flex at all and are firm..yet read 5 psi..im confused??is there a reason for this??

  • dr x

Posted August 25, 2007 - 02:46 PM


when tyres get old they get stiffer, that could be why....

  • bigwake

Posted August 25, 2007 - 02:52 PM


so that would make a tire that rides and seems totally normal..to read at 5 psi? because he has no problems riding..but when im in sandy roads..i get speed wobble like crazy..and it scares the crap out of me..

  • dr x

Posted August 25, 2007 - 03:04 PM


if the tyre has hardened off its not going to change the pressure reading.....
just wont flex as much, as for your speed wobbles that could be a few different things.

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  • bigwake

Posted August 25, 2007 - 05:53 PM


maybe his tire is hardened..but about mine..would you think i could have my psi at about 7 front 8 back? im 250 with gear

  • flintlock28

Posted August 26, 2007 - 06:13 AM


Tires have different sidewall stiffness, plus depending on whether a normal, Heavy-duty, or Extra Heavy-duty tube is used, you'll get different amounts of "Flex".

Some tires have very stiff sidewalls, and don't bulge much under load, while other tires with less stiffness will bulge considerably more. Use the below method to set tire pressure.

Rim Clean Method of setting tire pressure:

Set your tire pressure at what you assume to be o.k. for the terrain you ride....probably about 11-15 p.s.i.

Make sure your rims are clean, and then go ride the bike in either somewhat Dusty, or muddy conditions. Ride enough time to get the rims dusty or dirty, and than examine your rims right where the tire makes contact with the rim.

You should see a strip of cleaned rim that has been caused by the tire "folding" over the rim, thus "cleaning" off the dirt, and leaving a strip. Measure this "cleaned" strip, and it should be about 4mm in width. If it's less than 4mm, than you have too much tire pressure, and need to go lower in p.s.i. If the strip is more than 4mm, than you need to go up in tire pressure. Set pressure to what gives you 4mm, and you will have optimum traction for the TIRE and TUBE that you're using. All off road tires are designed to "fold" over the rim somewhat, and leave this strip.

  • bigwake

Posted August 26, 2007 - 06:51 AM


i'll try that thanx!

  • Jekel

Posted August 26, 2007 - 07:43 PM


That is some good info. I will try to look at this now:-)

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