The Official, thus-spake-those-in-the-know, word from RBW (6/27/07):

"Jack Brown is our new 622 x 33.3333 roadish tire.

Jack Brown GREEN is like a Roll-y Pol-y in that it has a light casing, normal 1.5mm tread thickness, and no kevlar belt. It weighs 295g.

Jack Brown BLUE is like a Ruffy Tuffy in that it has a stronger casing, an extra .5mm (to 2mm) tread thickness, and a kevlar belt. It weighs 435g.

A Rolly-Pol-y/Ruffy Tuffy is 27-28mm wide its diameter is 686mm. (A typical 700x23 has a diameter of 675mm.) The Jack Brown is 33.3mm wide and its diameter is 700mm. We're riding samples now, and they mount easily and seem great.

Mark here, local fast guy, got his fastest time up the mountain in 10 years on JBGreens, and rides them all the time on trails, too. But he's 140lbs and really good.

Most people should go like this:

Road riding only, decent roads: Green
Anything goes and tandems: Blue

We should have stock by July 15. "

click photos for full-screen image

Jack Brown Tire - Green Label Version (4/8/07)

Here's the first actual sample Jack Brown, and some facts & figures:

It is basically a fat Roll-y Poly, when the label is green (the Jack Brown Green). That means the casing is light, the tread is 1.5mm thick--which is normal for a light road tire; the bead is kevlar, and there is no belt.

Comparing it to a Roll-y Pol-y:
RP diameter and width: 27mm/686mm
JBGreen diameter and width: 33 to 33.5mm/ 700mm
The weight is 295g, which beats our 300g target.

It specs out as a super dreamy fast cushy road tire this way. Panaracer is working on the diameter, trying to nail 33.333333, but that is impossible, of course, since diameter depends on rim width, tire pressure, and casing stretch, and casings absolutely stretch over time.

There will also be a JackBrown BLUE--same thing, but with a blue label behind the Jack Brown name, and: --a thicker, tread (like a Ruffy Tuffy) --and an inner reinforced casing for puncture protection and cut resistance.

Don't have a sample of that yet, don't know the weight, but for mixed road and trail use and tandems, this would be a good way to go.

We should have twenty tester tires (at least the Greens, maybe some Blues) by about April 20, and production by June 1 or so. Although, of course, we've never met a deadline--but that is what I'm told.

I don't know how exciting this is to others--it's just a tire, after all--but to me it's a huge thing,

It will fit any road frame we've ever made, but no Jack Brown plus Fender on a Rambouillet---it's too fat for that. For the A. Homer Hilsen, no problem.

Best, Grant