This 700C tire was developed for riders (like us) who want a fast, light, high-volume and cushy tire, and at the time of its conception and birth, I'm pretty sure it was the only tire to fill that slot. Jack is about 33.333333mm in diameter, so it won't fit most road bikes with carbon forks, but that's more a fault of the fork than the tire. It will fit any cyclo-cross, touring or tandem frame out there--unless you happen to find one with shamefully tight clearance.
Jack Brown's radius is 350mm, so you need about 354mm between axle and metal. This is an easy measurement to take, but requires x amount of precision and care. The GREEN version is like a plumper Roll-y Pol-y, in that it has a normal casing and tread, with no beefening-up features (thicker casing, kevlar belt, extra rubber) that would add weight. It is the one we recommend for pure road riding.
The BLUE version is the same volume, but has an extra strong casing, kevlar belt, and thicker tread, so it weighs more. We recommend the BLUE for trails, commuting, tandems, or just all-around riding if you aren't weight-obsessed. Both are made for us by Panaracer in Japan. There's nothing to say you can't run a blue in back and a green in front (or vice versa, for that matter).
Made in Japan