should MTB bike tires be rock solid?

fguihen

I have a road racer and advice is generally to keep tires as hard as possible.

Recently ive tried out a few Mountain bikes in various store and all have had moderately soft tires. i know they will prob be softer than tires of a road bike, but these were very soft.

is there some logical reaosn for this?

RobFowl

They grip better when softer. Off road this makes a big difference.

Those MTB types will be able to explain better.

Morgan

Like the man says - better grip.

I run up to 120psi on my road bike but rarely over 30psi on the mtb.

zil

Lower psi = more grip but also more risk of pinch flats and higher rolling resistance.

If your running with tubes then you probably don't want to go under 40 psi otherwise you'll be getting a pinch flat every 2nd spin. If your running tubeless you can go as low as you like but I wouldn't say go much under 20-25 otherwise it'll feel like you have an elephant on your back when your going uphill due to all the resistance.

Gavin

zil wrote: »

Lower psi = more grip but also more risk of pinch flats and higher rolling resistance.

If your running with tubes then you probably don't want to go under 40 psi otherwise you'll be getting a pinch flat every 2nd spin. If your running tubeless you can go as low as you like but I wouldn't say go much under 20-25 otherwise it'll feel like you have an elephant on your back when your going uphill due to all the resistance.

Depends on your tyres and riding style. I got away with around 25-30 psi in my tyres without a puncture for ages. Halo Knobblers and I ride like a pansy.

-Chris-

You should also vary it depending on where you're riding - if you're commuting on it you can pump the tyres pretty hard, but if you're on the muddy stuff you'll get better grip if they're (relatively) soft.
Where will you be riding it?

fguihen

bit of both really, but its a pretty good bike so wont be bring it into town and locking it to a fence or anything, so more leisure cycles on road that lead to off road tracks

-Chris-

If you're mostly on tarmac you can pump them pretty hard, but be warned that the harder you go with knobblies the less grip you get for cornering. If you're on concrete/tarmac a lot you should get smoother tyres.

If you're off road, you can probably judge it by feel. Pump them hard enough that they're not uncomfortably hard and that the back wheel doesn't spin when you're pushing hard, but not so soft that you ever feel the "rim hit the ground".

Idleater

zil wrote: »

If your running tubeless you can go as low as you like but I wouldn't say go much under 20-25 otherwise it'll feel like you have an elephant on your back when your going uphill due to all the resistance.

I run tubeless at 20 - 25psi. Full sus too - but run the damping quite hard. I tried 30psi but prefer the grip and control on the roots, damp ground and gravel. Shows how long I have not been out on it

zil

nereid wrote: »

I run tubeless at 20 - 25psi. Full sus too - but run the damping quite hard. I tried 30psi but prefer the grip and control on the roots, damp ground and gravel. Shows how long I have not been out on it

Stronger legs than me then, first spin after getting tubeless I tried 20psi, ended up having to granny ring every single climb.

Enduro

The best rule I heard was that tyres should be as hard as the ground you're riding on.

Personally I run tubes at 50psi+ and tubeless at about 40psi. I hate punctures, and prefer to learn to control the bike properly at those pressures.

Idleater

Enduro wrote: »

The best rule I heard was that tyres should be as hard as the ground you're riding on.

Best advice, will take that on board!

Enduro wrote: »

...and prefer to learn to control the bike properly at those pressures.

Wheat from chaff! I've been found out

Now then, all I need is for the aul knee to repair itself and I can set about improving my control!

EamonnL

I don't know if it is true but I always believed that part of the reason for soft tyres on a MTB was because it is faster. i.e. the bike does not have to bounce up and over every pebble on the trail but can ride smoothly over, more efficient and less energy wasted.