Forum home Road cycling forum Road beginners

loss of tire pressure

fatblokefromwarwickfatblokefromwarwick Posts: 331
edited October 2009 in Road beginners
Just had my Trek 1.5 a little over two weeks and almost immediately fitted Michelin Pro 3's on Bontrager race x lite tubes.
As i'm new to the dark side :wink: Is it normal to lose 35psi on both tires in this timescale?
Had been running them at 115psi & felt soft on the ride home so checked hence the question. Cheers.

Posts

  • Mine did that the first couple of times but are fine now touch wood :roll:
  • FlasheartFlasheart Posts: 1,278
    I find my rear tyre loses pressure over a couple of days. I just make a point of getting the track pump out and topping front and rear up to 115psi before every ride..
    I don't want any visits from the P"££$%% Fairy now do I? :roll:
    The universal aptitude for ineptitude makes any human accomplishment an incredible miracle. ...Stapp’s Ironical Paradox Law
    FCN3
    http://img87.yfrog.com/img87/336/mycubeb.jpg
    http://lonelymiddlesomethingguy.blogspot.com/
  • Not sure if this is "normal" per se but I get the same thing. Tyres lose approximately 60psi in a week (from 120 to 60) front and rear. I'm not so bothered as the track pump is stored next to the bike, I generally ride out from home and the bike is only used for riding out rather than commuting.

    Two minutes with the track pump and everything is fine - and less effort than trying to "fix" it and probably creating a new issue ;)

    While this may not be normal for some, I do think that a lot is being asked of the inner tube and valve to store air at 8 atmospheres for a long time!

    Neil
  • FlasheartFlasheart Posts: 1,278
    I even changed innertubes and brands of innertubes and it still happens. I think that they must be porous to an extent and as DubaNeil said 8 atmospheres of pressure is a lot trying to escape.
    The universal aptitude for ineptitude makes any human accomplishment an incredible miracle. ...Stapp’s Ironical Paradox Law
    FCN3
    http://img87.yfrog.com/img87/336/mycubeb.jpg
    http://lonelymiddlesomethingguy.blogspot.com/
  • Just had my Trek 1.5 a little over two weeks and almost immediately fitted Michelin Pro 3's on Bontrager race x lite tubes.
    As i'm new to the dark side :wink: Is it normal to lose 35psi on both tires in this timescale?
    Had been running them at 115psi & felt soft on the ride home so checked hence the question. Cheers.

    yes it is


    but they are called tyres thats t-Y-r-e-s on this side :D
    'dont forget lads, one evertonian is worth twenty kopites'
  • Just had my Trek 1.5 a little over two weeks and almost immediately fitted Michelin Pro 3's on Bontrager race x lite tubes.
    As i'm new to the dark side :wink: Is it normal to lose 35psi on both tires in this timescale?
    Had been running them at 115psi & felt soft on the ride home so checked hence the question. Cheers.

    yes it is


    but they are called tyres thats t-Y-r-e-s on this side :D

    Yes, I often feel the need to point this out! So many people spell "tyres" as "tires". We may have MacDonalds, KFC, baseball caps and jeans but we're not actually American.... Yet....
    Do not write below this line. Office use only.
  • amaferangaamaferanga Posts: 6,789
    Bear in mind that as you attach a track pump the effective volume of air increases (tube + barrel of pump) so the pressure decreases. So while tubes do loose air over time, as soon as you attach the pump you're not actually measuring the pressure the tubes were at.

    I don't really have a feel for how much this is though - could be a couple of psi, could be more....
    More problems but still living....
  • neil²neil² Posts: 337
    Just had my Trek 1.5 a little over two weeks and almost immediately fitted Michelin Pro 3's on Bontrager race x lite tubes.
    As i'm new to the dark side :wink: Is it normal to lose 35psi on both tires in this timescale?
    Had been running them at 115psi & felt soft on the ride home so checked hence the question. Cheers.

    yes it is


    but they are called tyres thats t-Y-r-e-s on this side :D

    Yes, I often feel the need to point this out! So many people spell "tyres" as "tires". We may have MacDonalds, KFC, baseball caps and jeans but we're not actually American.... Yet....

    And it's amazing how many people can't spell McDonald's :wink: (or was that also a subtle one...).

    Anyway back to the point - I'm far from an expert on this but my limited understanding is that latex tubes lose pressure quicker than cheaper (heavier) butyl ones, but I have no idea why!

    Anyone care to confirm / enlighten us?
  • Thanks for the comments regarding my tires, I did think that their color had something to do with it :wink:
  • Thanks for the comments regarding my tires, I did think that their color had something to do with it :wink:

    GRRRRRRRRRR! im getting angry now! :lol:
    'dont forget lads, one evertonian is worth twenty kopites'
  • redddraggonredddraggon Posts: 10,862
    neil² wrote:
    Anyone care to confirm / enlighten us?

    Latex has a Higher permeability
    I like bikes...

    Twitter
    Flickr
  • gavintcgavintc Posts: 3,009
    tyres lose pressure NOT tires loose pressure. Please.

    Your tyres lose pressure quite quickly. I pump mine up every couple of days and note a drop of around 10-15 psi.
  • feelfeel Posts: 800
    It will take longer for air to leak out through thicker (cheaper and heavier) rubber than thinner (lighter and more expensive) rubber inner tubes. Same principle as party balloons deflating after a couple of days.
    Plus as mentioned above every time you check pressure you will lose a bit, but if you use the gauge on your track pump you will lose a lot.
    We are born with the dead:
    See, they return, and bring us with them.
Sign In or Register to comment.