cogdriven 

Anybody know for sure whether you get better traction with studded tires when you run them at the upper end of the recommended pressure range or the lower? I run mine a little soft to get more gription out of the rubber, but I'm thinking that this may allow the studs to "sink" down into the rubber rather than digging a little deeper into the ice. About two miles of my commute is on frozen, hilly, dirt roads, always an adventure, especially coming home in the dark.

Thanks

aggiegrads

Are you asking specifically about grip on hardpack/ice? If so, the more studs in contact with the ice, the better. I run my hard when I know the pavement is going to be dry, and drop the pressure when I know that there is ice.

Even when soft, the studs will dig into the ice before they sink back into the tire.

noglider 

I'd think that if the road is hard, you'd want hard tires. Low pressure will spread your contact patch and reduce the amount you dig a rut into the snow/whatever.

xtrajack

I go upper end for mostly dry roads, run them a little lower if it is storming.

modernjess

I know for sure that for me they perform better in snow and ice with less pressure. And when I say "perform" I mean they get better traction and are more stable in sketchy conditions. I vary the pressure based on the conditions I'll be riding in from day to day if necessary, it's just something I've learned through experience in my conditions.

neil

Lower pressure will give you more grip. More surface area in contact with the ice means more traction.

jimblairo

I run Schwalbe Ice Spiker Pro 26" and I've run them at 50 psi and as low as 25 psi with a tubeless set-up.

Lower PSI definitly gives better traction but I had to stop running tubeless b/c the spikes gripped too well and the tire pulled away from the rim on two occasions.

jeffpoulin

If you haven't read Peter White's article on studded tires, you might want to give it a read. Basically, when riding on ice, the stud's "path of least resistance" is to sink into the ice rather than sink into the rubber. You'd have to run your tires at VERY low pressure for that to change. If you have more than 30psi in your tires, you're probably fine.

bent-not-broken

My Nashbar (Kendra) studded tires are designed so the studs are on the outer edges of the tire. At max pressure they just touch the road as the tire center takes more load. Dropping the pressure allows more stud contact.

droy45

I would agree with this

fietsbob

On the days I get out the studded tire Bike , the ice has been such that I had a hard time walking on it, on the sidewalks,
But riding the bike , was significantly, more secure..


[specifics]
26x1.9" Nokian Mount and Ground W 160 stud, on All Weather Sports Snow Cat Rims (4.5cm wide)
using Sturmey Archer Drum Brake Hubs.

cogdriven 

Thanks for all of the great advice, especially the reference to Peter White's article in jeffpoulin's post #8. The decision is unanimous, both here and in the Winter Biking Forum. I figured this is what I would hear, but I am always willing to entertain the non-intuative approach, if there is one. There is a lot of good information in White's article and I've found another bike shop worth checking out, as I live only about an hour away from his shop.

sirtirithon

I have been running my rear studded tire (2.1") at 25psi,

Burton

Might depend on the tire width and compound being used - which can vary with make and model. I'm running Nokian 240's and although some Internet references give them a psi range of 58 to 65psi, the only thing marked on the side of my personal Nokians is INFLATE TO 65PSI.