5kdad

I need to put new tires on my mountain bike. I never ride the mountain bike trails. My riding is split between paved roads and the many dirt roads we have in rural, rocky Arkansas. The dirt roads often have loose gravel, so it's not always smooth. The bike has 26" tires. What factors should be taken into consideration, to decide if I should buy 1.75" or 2.00" tires???

canklecat

Sounds like my Texas rides, a mix of smooth city and rough rural pavement, brick, chipseal, gravel roads and some open fields -- but no mud or stunts. I've been riding a set of Michelin Protek Cross Max 700x40 for almost six months and am very satisfied. All terrain chevron type tread pattern.

They're a bit heavy but puncture resistant -- no flats so far, and the grass burrs that gave me fits with my previous tires can barely penetrate the Michelins. Great grip on everything I've tried. Looks like they're wearing well too.

I run lower pressure than Michelin recommends for my weight (around 75 psi for my 165 lbs). Above 70 psi up to the maximum 86, the Michelins feel a bit too rigid and tooth-jarring on rough pavement. The sidewalls are stiff. They're fine on smooth pavement at 65-70 psi, but I usually ride 'em at 50-65 depending on the main surfaces I encounter. They're about right at 50 psi on gravel, fields, and rougher trails -- less sideways jouncing from sideswiping large gravel.

Retro Grouch 

The first thing to look at is what size tires came on your bike originally. I'd assume that most mountain bikes would accept 2" wide tires but the path to hell is paved with good assumptions. Tires that are too big can rub in all sorts of places that might surprise you - like your front derailleur the first time that you try to shift into your granny chain ring. Your current tire size will also get you the number for matching your rims. It's a good place to start.

Narrower tires. as general rule, will handle more air pressure. A wider tire will allow you to use lower air pressure for a cushier ride while maintaining the same rolling resistance.

It's easy to overstate how much tire tread helps. I like slicks or minimum tread tires for everything except soft sand or climbing rocky single track trails. I have some big thick tread Continental Town and Country tires on my beater mostly for their puncture resistance.

As I write this I'm in the process of building an old mountain bike frame into a gravel grinder bike. It's getting 1.75" Panaracer semi slick tires that I expect to run at about 75 psi.