Touring - wheel sizes

what are the advantages of 26 inchers over 700's?

One thing is that I'm told that 26" wheels were developed to be similar radius to 700c with the different size tire installed. so the attempt was not really to create a difference in the first place.

26" have more tire options toward the fat end, so if you are a 1.25 tire or larger person, this is your rim, 700C is the reverse, perfect for the person who wants loaded touring at 37mm through to say 28MM for light touring.

Beyond tires, the smaller wheel is stronger. You can go to 36 spokes and have the effect of a 700c at say 40 spokes while using relatively standard components. In addition for the same hub the rigging angle is more favourable, again stronger smaller wheels. The smaller wheel is lighter, and the distance from center is lower, which means it's esier to spool up and keep spooled up, a big factor in quickness and energy overall. The larger wheel is better rolling relative to roughness in the road, which is present even in a fairly smooth road; and rolls better relative to hub friction, might be a factor with a generator a pro on the downhills, an con for spooling up. Large wheels roll over bumps more easily and are easier on your body because the ride is smoother.

Gearing wise the smaller wheel has a natural abilty to deliver lower gears, while maintaining a tighter gear spacing, and less problems from chain suck and so forth. On the other hand you would have to choose the lower gearing, it's worse for you if you want a high gearing.

The smaller wheels take up less space on the frame leaving room for fenders, racks and for the whole machine to be lower in the wind. Of course this assumes that the frame was built to take advantage of these features... Smaller wheels provide more fit options since a large rider can easily ride 26" wheels, while 700c can be worse for small riders.

Parts for smaller wheels are easier to carry, so your extra tire and tubes weighs less. And parts are generally easier to find in most place in the world. Often seems as though for the same rim the smaller wheel is easier to change tires while fixing flats, though that sounds wrong so maybe the rims aren't really the same.

Larger wheels brake more effectively with rim brakes, but less effectively with disc.

The biggest advantage for 26" wheels is that you can find tires and tubes basically everywhere.

That's my biggest concern also. Though the chance of finding touring replacement worthy tires is probably less than 700C. That's why I carry a spare folder. However finding something is better than not finding anything.

whew! thanks pan1, all my ?'s answered, and then some.

My bulletproof wheelset for a touring single bicycle:

Rear:

Phil Wood 40 hole tandem cassette no dish 145mm hub
26" Sun Rhyno Lite rims
DT Alpine III triple butted spokes
26 x 1.5 Schwalbe Marathon tire

Front:

Hugi 36 hole tandem high flange hub
26" Sun Rhyno Lite rim
DT Alpine III spokes
26 x 1.5 Schwalbe Marathon tire

One unusual thing happened with the wheelset. All of the spokes are the same length, left & right, front & back.

what are the advantages of 26 inchers over 700's?

Rivendell builds their smaller Atlantis frames to fit 26" wheels, and 58 cm frames and larger have 700 wheels. This leaves more room for fenders and a third water bottle, it lets the frame builder use a steeper head tube angle if he wants to build the bike that way, and it reduces the standover height of the bike for a smaller rider. It also reduces the problem of toe clip overlap on a smaller frame.

Toe overlap, I need to add that one. I almost had a tragedy on that score.