Rear Wheel on a Recumbent ( Pick One )
 

A) 26 x 1-3/8" or

B) 26 x 2.125"

How many places did you post this question??

Are you asking what we have? Or asking what we would choose? If you are you may want to consider making this into a poll.

BTW, I run a 26" x .875" on mine. And a 20" x 1.35" on the front. I wish I could find a narrower tire for the front in the Primo brand. I have tried other brands, but do not like the way they feel, handle the road surface. Or I have had to much bad luck with premature wear & side wall blow outs. With the Primo's I have never had a problem with any of this. They are a very good tire as far as I am concerned.

I don't know anybody who has a 2.125" tire on the back of their recumbent. Of more than 100 bents in my club, the majority use 28mm or less, with a significant minority using up to 1.5" and a handful using 1.75". I have a 25mm on my go-fast wheels and a 32 on my training wheels.

BlazingPedals, what kind of bent is your primary ride?

A Labent by Ladue just got finished powder coating after the frame was built to my specs. 225lbs here. He did a fantastic job on it. I can't wait.

All flat terrain in South FL. 100% asphalt riding. And I'm trying to get ready for it.

I had no idea that these wheels had diff. diam. rim. So I just learned that the 26 is the total overal diam. I thought it was the diam. of the rim. Boy learn something every day. The brakes I guess will determine which rim I use.

My primary ride is an Optima Baron. Go-fast wheels are Velocity Thracians, the training wheels are Vuelta Airline rims built on Shimano XT disc-compatible hubs.

As a newbie, I often find tire sizes confusing. The best resource I've found is Sheldon Brown's article on tire sizes:

http://www.sheldonbrown.com/tire-sizing.html

Thanks, that's a good reference. I think I'm more confused now though.

We'll see where the brakes are. That'll pertty much decide it. I think he said he's using a mtb rear triangle, so that'll probably mean the wider rim.

Even among MTB's, there's a lot of variation in tire width. My son's MTB has 26 x 2.125 tires; my MTB has 26 x 1.75. The rims are the same diameter, 559mm (measured from bead to bead, not outside edge to outside edge), so they should accept similar brakes. I'm still new at this, but as far as I can tell, you can get 559 tires in much narrower widths (down to 1" or less). These should work with the MTB rear triangle and brakes. So, my guess is that you can run whatever width you want, more or less, as long as you stick to the 559 rims and tires (26-inch with the width expressed as a decimal, e.g., 26 x 1.25, 26 x 1.5, 26 x 1.95, etc.)

...so long as the tire will physically fit in the frame. If World Tour's bent uses a MTB rear triangle, I would expect it to handle at least 1.95 wide tires, as long as the rim can handle it - you don't want to mismatch the width of the rim and tire.

I've never tried changing tire sizes on a given set of rims. How much leeway do you have, roughly? Obviously, you can't replace 26 x 2.125's with 26 x 1.0's--but how much can you you up or down in tire size?

As with most cycling subjects, Sheldon Brown has a page on mixing tires and rims. It's at http://sheldonbrown.com/tire-sizing.html
Here's what he says about tire widths:

Near the bottom of the page is a chart showing his guidelines of what width tires to use with what width of rim.

Somehow I missed that chart. That's what I get for skimming.

You guys have been great in helping me understand and learn about this stuff. I had no idea.

Well, I put a 26x2.0 on a 559 rim to use on the rear of the bent. Listen to me, a week ago, I didn't know what 559 meant. hehehe.

Thanks.
ps, Denny Ladue (Labent by Ladue) is a master craftsman. My frame is awesome.

Enjoy! And let us know how it goes!