Under Pressure

[Pale Rider]

You'll be skipping about on hard surfaces, and losing grip on hardpack stuff...... you may detect a bit of squirm, but the tyres won't be working with your suspension at those sort of pressures. Unless you're permanently on tarmac fully loaded, try dropping a few psi at a time and see how much your grip improves. The tyre knobs need to be able to conform to the trail, and much more than 40 psi won't let them do that.

Thanks for that, I did wonder if I'd been a bit over-enthusiastic with the track pump.

 

[mrbikerboy73]

I run 25-30 Front and 30-35 rear on a full-sus MTB. I only weigh 10.5 stone so anything more and there's not a lot of grip TBH.

 

[Justinslow]

There must be a compromise between rolling resistance and grip depending on the surface being ridden, therefore adjust pressure accordingly!

 

[I like Skol]

Check the sides of your tires. My road bike tires vary between 80PSI and 115PSI and I keep them at 110PSI to allow for post inflation pssssssssst...also because I prefer the solid feel to the spongy feel, but that's a personal thing

As has already been pointed out MTB Vs road bike pressures are two very different beasts.

25 fr 30 rear on both bikes, .........

Jeez, at those pressures I would be stopping with pinch punctures several times a ride! I run about 40Psi Fr and 45Psi Rr on my hardtail (14.5st & 26x2.1") and still get the occasional snakebite when hammering down rocky stuff (Like the Hayfield side of Jacobs Ladder recently ). I have wondered about tubeless as for me I think 5-10 Psi less is optimal for comfort, grip and handling but if I run lower pressures wouldn't I be damaging rims even though might not be getting flats?

You'll be skipping about on hard surfaces, and losing grip on hardpack stuff...... you may detect a bit of squirm, but the tyres won't be working with......... much more than 40 psi won't let them do that.

I don't suffer too much, as you know

 

[Cyclist33]

Thanks for all responses, yes if I could clarify it was only MTB pressures I was enquiring about, hence why I posted in the MTB forum..!

Stu

 

[Cubist]

As has already been pointed out MTB Vs road bike pressures are two very different beasts.


Jeez, at those pressures I would be stopping with pinch punctures several times a ride! I run about 40Psi Fr and 45Psi Rr on my hardtail (14.5st & 26x2.1") and still get the occasional snakebite when hammering down rocky stuff (Like the Hayfield side of Jacobs Ladder recently ). I have wondered about tubeless as for me I think 5-10 Psi less is optimal for comfort, grip and handling but if I run lower pressures wouldn't I be damaging rims even though might not be getting flats?

I don't suffer too much, as you know

Those are on 2.1s though. A wider higher volume tyre run tubeless will make a huge difference to grip and prevent you dinging your rim. (ooer etc.) Even with a 2.1 it'll take a pretty catastrophic hit to smack the ri.

 

[Crackle]

I used to ride my old 26" Velociraptors (2.1) at 40 because anything below 35 felt like I was riding with a puncture but they were really square profile tyres, absolutely awful on the road but great off.

The 29er Nobby Nics (2.25) I have on this bike run well for me at 25 to 30 psi. Over 30 psi and the the wtyres start to skit alarmingly on a hard gravely surface. I've run them as low as 20 but as yet I didn't feel any benefit from that but certainly no hindrance either. Much better tyres on the road too than the old Velociraptors.

 

[Jody]

I run 25-30 Front and 30-35 rear on a full-sus MTB. I only weigh 10.5 stone so anything more and there's not a lot of grip TBH.

This ^ plus a bit of additional weight round the mid rift. Tubed wheels would be 30+ and for canal paths etc would be 45-50

 

[GrumpyGregry]

I'm a biggish lad, so 55-60psi in the back of the new Cannondale MTB and about 10psi less in the front.

The shop sent it out lower than that, but I detected some squirm from the back on hard surfaces.

about 10psi less than this works for me.

 

[bridgy]

This MTB tyre pressure calculator might be useful - http://mtb.ubiqyou.com/

 

[Motozulu]

Blimey - I'm a bit of a fat git at over 14 stone and I run (tubeless) 29 rear and 27 front, grip is spot on at that and not too draggy for me.

 

[Jody]

This MTB tyre pressure calculator might be useful - http://mtb.ubiqyou.com/

Good link! Reckons I should be running 29F and 31r. Tend to run the rear about 5PSI higher so the rear lets go first.