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Maximum Tyre Pressure

supermurph09supermurph09 Posts: 2,471
edited February 2013 in Road beginners
On my old Specialized Allez I often felt the rear tyre was getting a puncture as the bike seemed to squat at the back, that was until I bought a floor pump and pumped the tyres up to their maximum PSI. The next ride I could not believe the difference, sure the ride was a little harsh but the bike seemed to fly. PB's on a few regular segments proved that.

Anyway, new bike (Cube Agree GTC Race), 2 rides done and it appears I'm quite a few PSI short as there is a little give when I push the tyre down to test the pressure. So given the increased performance I noticed on the Allez I'm thinking of maxing out the PSI. Whilst I'd imagine this will make things a little quicker, what are the disadvantages. Increased p**ct**e chances? Less grip?

Thoughts please.

Thanks

Posts

  • Maxing tyre pressure doesn't make you go faster. The tyre has far less contact on the road and skips along. Sounds like you need to find a happy medium. I ride at approx 110psi and I'm currently 66kg.
  • Happy medium, without doubt. I'll be interested to check the pressures tonight to see what they are actually running. I'm 6ft and 80kg so not exactly a heavyweight.
  • slowbikeslowbike Posts: 8,498
    I used to ride at 110psi but have reduced that to 100psi because it skipped a lot ...

    I'm inbetween u 2 weight wise.
  • Some of the numbers you will read on tyres are distinctly more sensible than others (eg. I have heard of 700x23 road clinchers with 140psi on them), but in general don't assume to use them for guidance. Find a chart instead. Sheldon Brown's one is an example.

    P.S. I am also 6ft and weigh 63kg currently. I run my - 27 x 1 1/4" (32mm) - tyres at 80-85psi. The pressure you use has more to do with the volume of the tyre, and won't make you faster.
  • I use this chart that was posted on here a while back.
    http://www.bikequarterly.com/images/TireDrop.pdf

    Works for me :)
    "You really think you can burn off sugar with exercise?" downhill paul
  • I'd like to use that 15% drop rule but the pressure required is way way over the limit on my tyre - need to work on the spare one round the middle for a while longer before I can fit with that one :shock:
  • Skipping is a problem and when the road is greasy (like now) it makes it worse. I upped the tyre pressure from 80(front) 100(rear) to 90(front) 110(rear) at the weekend. Rode on sunday OK but on the way home tonight th rear was sliding around quite a bit and I had a slow speed off at a junction (nothing damaged just a bruised ego)
  • JahmooJahmoo Posts: 168
    Run both tyres at 80psi, also feel like the rear has a flat at times, so may up the rear a little but not to much, as said, roads are greasy.

    This confirms an issue I had when I changed my 32's for 28's running at the same PSI my speed dropped loads. The Graph showed less PSI in the larger tyre....thought I had gone mad, but now explained :roll:

    :)
  • GuernseyStuGuernseyStu Posts: 21
    edited April 2013
    jk,tdydvsdv
  • An interesting point for me is maximum tyre pressure certain rims can take. Older rims are going to be worn and more prone to blowing with higher pressures.

    I'm a lightweight at only 65KG, and my I have some fast Vredestien TriComp tyres. The MINIMUM recommended pressure on the sidewalls of those is 116psi! I think my Mavic SL rims are rated to the same Max pressure of the tyres which is 10Bar/145psi

    I've used them at 120psi on a super smooth tarmac track and handling was great. On the road however, the ride becomes very skittish.
    Ribble Stealth/SRAM Force
    2007 Specialized Allez (Double) FCN - 3
  • Had a couple of punctures so upped to 120 front and rear, not flats now and also seems to have made a significant difference to my times. I'm 5 11 and 70kg by the way.

    Ditto
    Cipollini Bond
    Pinarello GAN
  • 110 - 120 for me depends on the bike I'm on TBH. Never had an issue with the wheels feeling anything other than good.

    Personally don't like to run then too low as just introducing a greater potential for a pinch puncture & I've had enough of the on my race XC bike to not want to deal with any more on the road bike.
    Pain hurts much less if its topped off with beating your mates to top of a climb.
  • oldwelshmanoldwelshman Posts: 4,733
    Markjaspi wrote:
    Had a couple of punctures so upped to 120 front and rear, not flats now and also seems to have made a significant difference to my times. I'm 5 11 and 70kg by the way.

    Ditto
    Placebo effect :D
    Increasing to 120 will make no difference to performance.
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