Tube size question
 

Got some 700 x 47 Continental touring tires. Will a tube for 700 x 35-43 work?

Or would a 27.5 x 1.75 - 2.5 tube be a better choice?

The 700c tube will work fine. It's a little small, but tubes are stretchy.

I wouldn't be too surprised if you could get the 27.5 tube in there and inflated, but it would be much harder to correctly mount since the hoop diameter is so far off.

Blow up a tube as if to check for leaks. Notice how little pressure is required and how huge the tube becomes, relative to what it would be inside the tire. Never worry about "too small" tubes again!

Thanks. That's what I figured, and almost ordered a couple but these big touring tires are new territory for me & wanted to be sure. Thanks again.