Any recommendations for fold-up 1.5x20 & 1.5x26 tires I can carry in trunk for spares?
We take long rides on our Just-Two-Bikes side by side bents and have blown three tires... twice had to bum ride or walk home... once had a Walmart 1.75x26 in trunk but could only inflate to 20 lbs... rubbed on inside of fender.
How about trying kevlar-belted tires (or similar) and carry spare tubes.
I always carry extra tubes and have tire liners or kevlar tires on two of our four bikes we ride most. The blowouts were on a couple old bikes I bought recently with old tires. Have since replaced the tires with Primo Comets (kevlar). Still want to carry a fold-up spare on longer rides.
I use Schwalbe Marathon Racers in the sizes you are looking for and they are foldable. Great tire. I am averaging about 5000 miles per set