Tire size?

[vaporjourney]

I'm planning a bike tour for this April/May and am having trouble deciding on an optimal tire size.   I currently have some 2.20" knobbies which are great on dry trails and hardpacked snow around Crested Butte, but I know I'll need to swap these out for another pair for this trip.  I plan to ride about 75% asphalt, and the rest gravel roads.  Naturally I'll try to keep my load down and don't plan to rock some massive 4 pannier setup.  I'm looking at some Shwalbe Marathon XR tires (other suggestions?) which would be great for pavement as well as dirt/gravel, but can't decide on a tire size for my trip.   I'm leaning toward 2 inches, but would like the opinions of others.  An entirely likely scenario would be that I get completely sick of wide paved roads, and try to ride quiet dirt roads as much as possible..

[ScottM]

I'm leaning toward 2 inches, but would like the opinions of others.  An entirely likely scenario would be that I get completely sick of wide paved roads, and try to ride quiet dirt roads as much as possible..

I can see that happening. 

I'm a big fan of wide tires, even for gravel riding.  Just more comfy and stable.  When I race the Divide route I ran WTB Nanoraptors which are 2.1's.  The Divide is almost entirely gravel roads and pavement, and I thought they were good tires for the job.

I think the Marathons are a good choice, too.  Supposed to be very durable.

[frejwilk]

Without even knowing what wheel size you use, I'd agree with the Nanoraptors. One pair of 26" Nano's saw me through the GDR this year. Considering weight, volume, durability, rolling, etc, I can't think of a better tire - 26 or 29.

Now if you decide to go a lot further off road...

[Slim]

They even come stock on the Salsa Fargo touring bike I believe. Also did you read that article from the German Bike magazine and Schwalbe that a wider tire at lower pressure was faster on rough gravel then a slightly narrower tire, or one at a higher pressure? So I would sy go bigger: less rolling resistance, more comfort and control, more offroad capability.
BTW stated tire width bears little relation to actual width, some 2.0' are much wider than other 2.3's! Check the fori(forums? foria?) for real relative widths.

[vaporjourney]

edit:  just purchased a pair of the Nanoraptors for my 26".  They were dirt cheap at $15 apiece, so I couldn't pass it up.  Thanks for all of the advice, and reviews on mtbr lead me to believe that I've found the right tire.