I have 230 gram 25 mm Continental GP4000S tires on our tandem. But, I am seeing where 90% of pro riders in the Giro use 25 mm tires. I figure if a 140 lb. pro rider is most efficient on a 25 mm tire, this 290 lb. tandem team could stand to use a wider tire.

But the GP4000S doesn't come in 28 mm. I guess the obvious move is to the 260 gram Conti GP4 Seasons.

I looked at Michelin, but I don't see anything. The least bad 28 mm appears to be the cheapie 340 gram Dynamic Sport. What happened to the Krylion? That was a nice tire, and would have been a natural for the 28 mm.

There is the 235 gram Ultremo ZX with V-Guard, which appears to be Schwalbe's equivalent to the GP4000S, only it comes in 28 mm. Interesting that it in 28 mm it is only 5 grams heavier than the 25 mm GP4000S. I wonder how good that V-Guard flat protection is?

Another candidate is the Specialized Roubaix Pro, which is 700 x 25/28; psi 115-125; approx. weight 300g. What is 25/28? 26.5 mm?

Are there any other performance 28 mm tires we should consider?