Tyre pressure

mak3m
mak3m Posts: 1,394
edited August 2010 in MTB beginners
To date ive mainly ridden road, country track and flat easy trails on my hard tail, normally run at 45psi, tyre states min 40 max 65.

tomorrow going for my first trail ride on the follow the dog.

do i need to drop my pressure for this route or indeed should i be running higher on the roads.

sorry for newb q :oops:

Comments

  • chedabob
    chedabob Posts: 1,133
    Lower pressure = more grip but more chance of pinch flats and more rolling resistance. Low pressure on the road generally speeds up wear of the tyre.

    It's personal preference really. Just don't exceed the min or max of both the tyre and the rim as the tyre could come away from the rim or it could get blown off. If you find 45 psi doesn't give enough grip, drop it to 40. It also depends on the size of your tyres as wider tyres can have lower pressures without getting pinch flats.
  • robertpb
    robertpb Posts: 1,866
    Low pressure off road is low rolling resistance.

    Tyre pressure should be adjusted to your weight and tyre size.

    On the bike I weigh 66kg and run 23-24 up front and 25-26 out back on 2.25's

    To put 45psi in the tyre you would need to weigh 130kg.

    Most tyre companies are now using 29psi for a rider weight of 75kg, add 1% for every kilo over that.
    Now where's that "Get Out of Crash Free Card"
  • mak3m
    mak3m Posts: 1,394
    cheers matey

    as im a little on the chunky side will go down to 40

    when you do the math i will :oops:

    lol
  • robertpb
    robertpb Posts: 1,866
    How chunky?

    Then I will do the maths
    Now where's that "Get Out of Crash Free Card"
  • mak3m
    mak3m Posts: 1,394
    lets just say i added 40% *cough*

    :lol:
  • Bar Shaker
    Bar Shaker Posts: 2,313
    If its very soft ground a lower pressure will help the tyre float across the top. Otherwise, I ride with my tyres between 40 and 60psi, depending on the trail smoothness. Rougher trails seem easier if the pressure is at the lower end. Climbing definitely gets better traction with lower pressures.
    Boardman Elite SLR 9.2S
    Boardman FS Pro
  • t0pc4t
    t0pc4t Posts: 947
    am I doing it wrong then? I normally run my anthem at about 30 or just under

    have not (yet) had a pinch flat
    Whether you're a king or a little street sweeper, sooner or later you'll dance with the reaper.

    Cube Curve 2009
    Giant Anthem X4

    FCN=6
  • robertpb
    robertpb Posts: 1,866
    If sub 30psi is good enough for all the world and ex world champions I have asked then you are OK.
    Now where's that "Get Out of Crash Free Card"
  • Anonymous
    Anonymous Posts: 79,667
    i am a big old unit and i run my tyres at 30 on the front and 40 on the back. i find this allows the front wheel to deform around the trail and not get deflected by it so it is easier to control, i leave the back pumped up more as i find it helps with the rolling resistance and the back i easier to control if it gets a bit out of shape.
    i am using tubeless setup and ride slowly enough that pinch flats arent something i need to worry about.
  • t0pc4t
    t0pc4t Posts: 947
    do you even get pinch flats on tubeless? I thought a pinch flat was when the inner tube gets caught between tyre and rim?
    Whether you're a king or a little street sweeper, sooner or later you'll dance with the reaper.

    Cube Curve 2009
    Giant Anthem X4

    FCN=6
  • Anonymous
    Anonymous Posts: 79,667
    t0pc4t wrote:
    do you even get pinch flats on tubeless? I thought a pinch flat was when the inner tube gets caught between tyre and rim?

    it is possible, ive seen photos of people's pinchflatted tubeless set ups but i was referring to the genrality of the fact that i typically canget away with i think seems to be low pressures for my hulk due to the fact i dont ride hard. as a big bloke i would expect to need more pressure if i rode harder but the relatively low for my size pressure i run are ok.

    i was trying to put the whole thing into a perspective of some sort.
  • mak3m
    mak3m Posts: 1,394
    well i dropped to 40 and lost the front a few times on the trail

    next time will try the dropping the front trick :D try 35 then maby 30
  • nicklouse
    nicklouse Posts: 50,675
    looked in the FAQs it is well coved in there.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • mak3m
    mak3m Posts: 1,394
    balls sry will seek in there next time :)
  • I usually run the back a bit higher than the front to give it a bit less grip. I'd much rather the back to slide than the front! I do have the same tyre on f+b though, which will make a difference to the balance you choose.

    If it's horribly wet and muddy, run your tyres a little higher to slice through the wet mud. If it's really dry and dusty, put a little less pressure in to have some more grip on the lose surface.