I got a couple of maxxis swampthing 2.35 tyres, they claim to be downhill tyres, but on the sidewall they say “inflate to 30-60 psi”.
Surely they’re wrong?
I wouldn’t dream of pumping them up to even 30, let alone 60.
I got to 20psi, and they felt too hard, so I let a bit out till they were at about 15, which feels on the hard side of what I would normally have them at.
Why do they tell me to inflate them to 30psi?

20 psi – are they not squirming about>

I would think the 30 psi minimum is to stop them rolling off the rims.

I run all my tyres above 30 psi – I hate the squirming of a soft tyre

the reason is to prolong the life of the tyre side wall. if you run your tyres at sub 20 psi a lot then you’ll see diagonal marks appear on the side of your tyres- showing some of the cording inside the tyre. this is due to braking or acceration creasing the tyre under load. saying that- some riders on the world cup circuit run pressures around 25 psi and they hit stuff hard! so its not unusual to run tyres as low as you do- they’ll just roll a bit slow……

the bontrager big earls that they replace which admittedly were 2.5 never “rolled off the rims”. I have got fairly fat rims.

the reason is to prolong the life of the tyre side wall. if you run your tyres at sub 20 psi a lot then you’ll see diagonal marks appear on the side of your tyres-

yes, this is exactly what has happened to my previous tyre!

I noticed that they had got quite bad and developed from creases into actual cuts, and the tube was poking through, which told me i needed to replace them.

But it has taken at least a year, and quite a lot of riding…

I would rather have to replace them more often than have poor handling. I guess I will go for a compromise of between 20 and 30, and see how it goes.

Don’t you get better handling with lower pressures – surely downhill riders don’t have high pressure tyres?

some downhillers run tyres pretty firm- to hold the shape in hard cornering, others run them softer. it is all about personal preference. nico vouilloz (who i guess knows what he’s chatting about)says he runs his tyres as soft as they can be without feeling like they are folding in the corners. but then some moto riders have their tyres well’ard

the reason is to prolong the life of the tyre side wall. if you run your tyres at sub 20 psi a lot then you’ll see diagonal marks appear on the side of your tyres- showing some of the cording inside the tyre.

Yeah, I get this. It certainly happened on my old Mud-X to the extent the inner tube burst through the side. I had got a lot of life out of it so didn’t mind. Still won’t stop me running my tyres at lower pressures….my perfect tyre pressure is just enough psi to limit pinch punctures…normally between about 25 and 30 psi.