I am planning a bicycle ride on Adventure Cycling's GDMBR Great Divide Mountain Bike Route this 2013.

For the trip, I am going to purchase a Trex Mamba which has Bontrager 29-2, 29x2.2" tires on a Bontrager AT-850 rim.

I'm smart, but apparently, not smart enough - and worse, the more I read, the more clear it becomes that I don't know jack.

Folks who have completed the GDMBR indicate that wider tires are the best for handling the soft spots like sand and loose dirt and for softening the ride.

When I read reviews of a newly found 2.5 tire, I find that it has poor durability or is not truly a 2.5 (more like a 2.3) or has weak side walls or better serves to alert you that you have just ridden through a patch of goat's heads - being flat before you can count to thirty.

And then when I find the perfect tire, I discover that fat tires sometimes take a different profile when mounted on a narrower rim vrs a wide rim - narrower resulting in a taller tire and wider rims giving a more rounded shape where the new shape then interferes with the shifter.

And then there's rubbing on the forks because of the swelling caused by mud being stuck to the wheel.

Dang it! I can't find the numbers for the rim, is it a 'wide' or 'narrow' rim? And I have no idea of what to measure for when it come to side clearance on front forks.

Any help? Actually, I'm tired of reading about TPI, plys, mm's, beads, and cornering - I want someone to just tell me which tire to order.