WTB Pushes “B+” Wheel Size With New Tire/Rim- by Guitar Ted

WTB Trailblazer B+

We got our first glimpse of the B+ wheels from WTB at Sea Otter this Spring.

While wandering around at Interbike’s Outdoor Demo at Bootleg Canyon a few years ago, I was tapped on the shoulder by a man by the name of Bob Poor. Many of you readers may not recognize that name, but you should if you are fans of twenty nine inch sized wheels. Why? Because Bob was instrumental in the push for “The Tire” back in the 90’s, which turned out to be the first large volume off-road specific tire that sparked the 29″er revolution. That tire is the Nanoraptor. Mr. Poor also was one of the first to hit the internet with a site whose sole focus was on 29″ers.  To say he had a big influence on the early development and popularity of 29″ers is not a stretch at all. And here he was, speaking in excited but low tones about a new idea he was getting behind that he had dubbed “B+”. I was promised a few e-mailed specifics but was asked to stay quiet for the time being.

Trailblazer B+

The WTB Trailblazer B+ tires and prototype rims on a special Rocky Mountain Sherpa show bike.

Time went by and all was quiet on the “B+” front, but Grannygear and I had occasionally theorized about such a wheel and what it might do and how it would fit into the current status of off road bicycling. Then early this year things began to percolate again concerning B+. Obviously, our report from Sea Otter, (seen here), showed that the concept had been realized  in the form of a show bike by Rocky Mountain dubbed the Sherpa. Bob resurfaced again and e-mailed me some more about the concept.

Essentially, the thinking is that while 29+ is a great idea, it is somewhat limited to those of larger stature and with the means to buy a completely new bike. How could one enjoy some, (most?), of the benefits of 29+ wheel but not have to “buy in to” another platform? Couldn’t a wheel be produced that might fit into many current 29″ers and still give you a “fatter tired” experience? WTB’s Mark Slate, at the behest of Mr. Poor, looked into these questions and found out that it could be done.

Trailblazer B+

An OS Bikes Blackbuck with the Trailblazer 2.8″ B+ tires (Image courtesy of B. Poor)

Mr. Slate, whose side project, OS Bikes which has as its only model, the Blackbuck, took one of his hard tail bike’s measurements and contrasted that with a B+ sized WTB Trailblazer spec and found it might work out. Indeed, as you see here, it does. The key is using a 584ISO rim diameter, (otherwise known as 650B), and mating that with a voluminous tire. In this case, the 2.8″ wide WTB Trailblazer. The combination measures out to just shy of 29″ in diameter, moving the widest part of the tire’s casing back just far enough to allow for it to spin freely in the Blackbuck’s stays.

Admittedly, the concept of a B+ wheel size won’t fit all 29″ers, and certainly, there would be custom builders taking advantage of the wheel and making “progress” by adapting designs specifically for these wheels and tires, but to know that this may actually work in many current 29″ers propels the idea forward with manufacturers, since the possibilities for selling more units is already out there. WTB is also moving forward with plans to make an “i45” rim like the one shown on the Sherpa show bike. It looks as though we’re actually going to be seeing this happening.

We’re excited about this development since it would be immediately accessible to many with the bikes out there that would fit the new B+ tires. Plus, the ideas that might be spawned from this idea are tantalizing to think of. Stay tuned as we suspect there is a lot more going on here than what meets the eye……