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Tyre Pressure


FOB's picture

By FOB - Posted on 15 September 2009

Hey,

being only new to MTB and doing the usual Dam, falls etc trails I generally run my tyres at 40psi, talking to a bloke on the weekend said that I should be running them at max 25-30psi ? seems to low but whats the G.O?

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Matt P's picture

Depends on a lot of factors such as your weight, type of bike, riding style, are you using inner tubes or tubeless tyres how big are the drops you do etc.

I’m about 120kg (plus gear, camelback etc) and tend to run around 40 on my rear and mid 30s on the front (track dependant) of my 6” travel, dual suspension trail bike.

I’d suggest riding the dam and reduce pressure by 2 psi each ride until you find a sweet spot of comfort but not having the tyre squirm when you corner hard. Also consider that as your skills improve you may be able to drop a little more pressure as you won’t be hitting some sections with as much impact.

It’s a bit of trial and effort but over time you’ll find whats best for you.

loki's picture

I'd be careful of dropping pressure too much if you are using tubes as you'll then be likely to get a "pinch flat" and wreck the tube.

I'm using tubeless and run 29-30 psi in the front and 34-35 at the back. I found dropping the front pressure gave me more front end grip and the bike wasn't as skittish going downhill on loose stuff. BTW I weigh about 75kg, 2.2" tyres, 5" travel dual suspension bike.

Let us know some further details and you will get some recommendations from people with a similar setup.

Scottboy's picture

I agree with Matt P , it comes down to weight , tyre type what the bike is and most of all how you ride .
I have been riding trails for over 2 months I hear the same about pressure but it all depends on your tyres too & the area you ride I always run my pressure around 35psi & I have tubes .

snowkiwi's picture

I've found that very generally harder tyres means a "faster", harder ride and can be squirly on slippery tracks while softer tyres means more grip and a "smoother" ride. Of course if you go too far in either direction it's not a good look.

And it also depends on where you are riding, why you're riding there, your bike setup (full squish, hard-tail, etc), your tyres themselves, your weight, your riding style, the temperature (tyres swell a little in hot conditions), how many spare tubes your friends are carrying, what you had for breakfast and what colour your undies are.

I also reckon you should go for lots of rides and try lots of different pressures till you find what you like. Besides - that's another great excuse to get out more, eh Sticking out tongue

hawkeye's picture

I haven't ridden off-road for about 6 months now due to injury Sad , but around the Dam I usually run 28-30 PSI on the front and 30-32 on the rear.

I run tubeless conversion and 2.1" rubber on a 5" travel bike, at about 85kg riding weight (once I lose this lard I've accumulated).

I have run below 20psi, but had enormous tyre squirm and burped the front tyre off the rim on a rock Shocked 25psi is the absolute lower pressure limit for me, I reckon.

spudatm's picture

Im 110 kg and run 42 in the front 46 in the back and haven't had a flat in six months {with tubes}.
My wife is 55kg and she runs at 30 front 34 back and has had one flat in the two years she has had her bike.
Mate of mine is about 80 kilos and going by my calculations runs 38 front 42 back and has had one flat in 12 months.

rangie's picture

add to mattp's factors, rim width, tyre type etc too. do not need tubeless tyres per se, just a bit more effort.

if tubeless, then start around 32-35psi and go up/down in small increments until you find your sweet spot.

more psi does NOT mean faster, it just means harder. When a tyre is too hard for conditions (track, your weight, etc) it will bounce over obstacles rather than rolling over them, like its designed to do. Bouncing over means up and not forward when it comes into contact with an obstacle. Therefore you will often have less grip, comfort, speed, etc.

At recent doctor, I (60kg max with gear) ran very skinny raven/crow at 24, 27psi front, rear respectively. Not one issue, very predictable grip levels and awesome ride on a hardtail so only a slightly sore lower back from the rougher sections of track.

FOB's picture

Righto

I'm 90kg currently riding a Giant boulder, with Maxxis advantage tyres/tubes mostly riding XC but will give most things a go once just to see if my body or the bike can take it

Thanks for all the feedback

snowkiwi's picture

I'd not considered the bounce vs roll aspect (and haven't ridden off-road much for a while either) when I said harder meant faster. Thanks for pointing that one out Rangie.

I guess that's part of why [a bit] lower pressure grips more, too.

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