Try running a set of nice set of 26" x 1.125" (~28mm) road tires such as the Continental Continental Ultra GatorSkin Black Duraskin or a Schwalbe Stelvio on your existing wheels and see how that goes.
Unless your Rhyno Lites or what ever rim you have on your tandem has a bead-seat (interior width of the rim) that's wider than about 22mm, a 28mm tire should work just fine and give you nearly all of the useable benefits of a second set of wheels with a few less spokes and a somewhat more ligher-weight narrow rim, that is unless y'all are going to be doing some serious time trials or other timed / competitive events.
Anyway, just an option that'll save you a few bucks... at least for a while.
Thanks for the response. I did put a set of 1.5 Specialized Nimbus tires on it. They have worked good so far for on and off road (rail trail) I'm not planning on racing with it , just trying to make up for our lack of ability.
We have Avocert FasGrip City 1.25 on RhynoLite rims. They're okay but I wouldn't go any narrower.
With two wheelsets my only concern is that the rim brakes line up properly when switching wheelsets. Anyone know if that is a valid concern?
FWIW the rim is 20mm wide inside.
Last edited by justcrankn; 06-24-09 at 10:08 PM.
Reason: measured rim
Yes, different wheels and rims will often require a minor adjustment of the brake blocks, both with regard to the alignment / brake block contact point with the brake tracks and with regard to brake lever travel if the rims have a different width at the brake track.
Another option would be to build your current hubs with some narrower rims, like a Sun 0 Degree XC or Velocity Aeroheat. That would be a good compromise for swapping between 28mm road tires and 2" fat tires, like Tandemgeek suggested.
I think you'll find 26" tandem road wheelsets rare on the used market.
We just picked up a bike with 26" wheels to try as a convertible. Traveling will be easier with just one tandem that we can use for road and off-road, with just a wheel swap or tire swap.