Tyre pressure advice

grant620

Hi all!
Recently got back into Mountain Biking after a 10 year break and SO much has changed!
Got a query regarding tyre pressures....
I'm running a Pace RC405XCAM with Rockshox Recon Race forks.
Tyres are Maxxis ADvantage 26x2.1 Foldings.
Having all sorts of grip issues and finding it very hard to hold a tight line.
So as a rule, what sort of pressures do people run in these tyres? If I can get this about right I can move onto other areas of setup!
Currently running about 33 front and 32 rear (below the recommended minimum anyhow!)
Any guidance would be appreciated.

Thanks
Grant

nicklouse

there are no rules. as there are too many variables.

Zeroman_IR

Welcome to the forum!
Those pressures don't sound too bad, I usually start at 30psi front/35psi rear and adjust from there. It's amazing the difference small adjustments can make though, a few psi either way can change how the bike rides.

What sort of terrain do you ride on? Are your shock and fork pressures OK? One of the fellas I ride with recently switched to an Advantage on the rear (from an Ignitor) and finds it much grippier and more predictable.

robertpb

Your tyre pressures are back to front, the back should be 2-3psi higher than the front.

You could put a wider tyre on the front for more grip.

You also have to adjust tyre pressures according to weight of rider, size of tyre, type of tyre and terrain.

The tyre wall pressures that different makers use vary quite a bit, but they are usually for a 75kg rider.

My tyre pressures I use are on 2.25s 23psi front 25psi back with an all rider weight of 64kg,

These pressures have been OK for the Peak District and Yorkshire Dales, before anyone says they might be all right in Essex but they won't survive a rock strewn track.

rhann

On road, about 5psi below maximum.
off road, I go for the halfway point, about 40 psi.

grant620

Zeroman_IR wrote:

Welcome to the forum!
Those pressures don't sound too bad, I usually start at 30psi front/35psi rear and adjust from there. It's amazing the difference small adjustments can make though, a few psi either way can change how the bike rides.

What sort of terrain do you ride on? Are your shock and fork pressures OK? One of the fellas I ride with recently switched to an Advantage on the rear (from an Ignitor) and finds it much grippier and more predictable.

Hi
Thanks for that.
Will drop the front pressure then. I'm about 71-72kg (depending on time of day )
Been fiddling with fork and shock pressures a bit and I reckon they are spot on.
Set them up with the sag as suggested, but ended up making small adjustments to rear as I was bottoming the shock out from time to time.

I'm tempted to swap the front tyre for something a bit more rounded in profile as the ADvantage seems pretty square and seems to drop onto the side.

RealMan

robertpb wrote:

Your tyre pressures are back to front, the back should be 2-3psi higher than the front.

The logic behind that is..? :?


For off road use, go for about 25-35 psi. For on road, maximum, so 50-60 psi. If you go tubeless, or you find you just don't pinch puncture much, could try 20-30 psi.

robertpb

RealMan wrote:

robertpb wrote:

Your tyre pressures are back to front, the back should be 2-3psi higher than the front.

The logic behind that is..? :? .

Well 25 years plus of riding MTBs has brought me to this conclusion, plus it's logical, plus every top rider, world champ I have ever enquired of has this set-up.

supersonic

robertpb wrote:

RealMan wrote:

robertpb wrote:

Your tyre pressures are back to front, the back should be 2-3psi higher than the front.

The logic behind that is..? :? .

Well 25 years plus of riding MTBs has brought me to this conclusion, plus it's logical, plus every top rider, world champ I have ever enquired of has this set-up.

Many use identical pressures though. It really does depend on a variety of things.

RealMan

I said logic...

JK in the UK

Some things people argue about just for the sake of it. Seriously, your question's a good 'un but it always opens a can of worms!!

General convention is slightly lower pressure on the front than the rear (for me normally 5 psi difference) and if you're running different width tyres, put the wider of the two on the front.

Other than that it's all experimentation! I find that I can really feel a drop of just 2 psi on the motorbike and that it has a serious impact on the way it handles. I also notice quite some difference on my MTBs. For example on my DH bike with my current tyres etc etc I like 22 / 27 psi. I don't feel happy if the front's over 25 and the rear's over 30. I weigh 65kg but these are 2.5" tyres so probably not representative of what you're running.

There's absolutely no logic to having a higher pressure in your front tyre as I see it. It is the rear that provides the majority of rolling resistance - the front provides grip. Go as low as you can sensibly go without pinch flats and let it rip. If you're not riding proper offroad or you're more into the distance game rather than seeking thrills, then obviously up the pressure...

grumsta

The logic behind that is..?

That you can run the back harder because grip is slightly less crucial than the front, and they will roll a bit faster.

supersonic

I know people that run less in the back on some hardtails - takes a bit of the sting out. As above, so many variables. What works for one may not work for another.

andrewjoseph

The logic behind having more pressure in the rear tyre is that more of your weight is over the rear.

Silenzio.eu.com

Well thats interesting. I have been riding for many years and now live in Italy (yes they have good trials), most trails are a mixture of dirt, roots, and rocks. I have always ben happy with a low presure of 32 psi rear and 28 front, until I read the Mavic wheel web site which gives much higer values. So I change the presure higher to give better rolling speed- tyres 2.2 with inner tubes (can not be fussed with all that gel) rider weight 77Kgs, Full suss with high fork pressure I like the bike to be firm and not bouncy .

Result, a wall jump out in front of me when the wheel skipped over a rock. It now handles like a swine (no offence pigs) and all over the shop. Gone back to orignal pressure and have better grip, especialy on corners with either rocks or more importantly loose gravel at speed!. It goes to say, start of with a pressure as suggested and make small steps to get the balence right and increase until you are happy with the speed and handling.

MountainPete

I run a lower pressure on the back (hardtail rider) - it makes the ride a bit softer, and I find I need the grip more on the back to get up those hills. My forks keep the front pressed into the ground.

XxxBFGxxX

i am 130kg i run my tyre at about 45 psi if on rooted stuff if its cross country i run about 50psi. does me fine

Dirtydog11

grant620 wrote:

Hi all!
Recently got back into Mountain Biking after a 10 year break and SO much has changed!
Got a query regarding tyre pressures....
I'm running a Pace RC405XCAM with Rockshox Recon Race forks.
Tyres are Maxxis ADvantage 26x2.1 Foldings.
Having all sorts of grip issues and finding it very hard to hold a tight line.
So as a rule, what sort of pressures do people run in these tyres? If I can get this about right I can move onto other areas of setup!
Currently running about 33 front and 32 rear (below the recommended minimum anyhow!)
Any guidance would be appreciated.

Thanks
Grant

Read this

http://www.schwalbe.co.uk/pdf/techinfo.pdf