There has been a lot written already about the 650B or "B" sized mountain bike wheels on the ol' innerweb lately. I suppose that a lot of folks are really sick of it all. I know I feel it's getting waaaay more play than it deserves now. However; with all of these opinions flying around, I thought I'd weigh in on where I'm coming from on this and where I think I'm going to come out on it.
For a good primer on a couple different viewpoints see this and this.
First off, I do not totally agree with either of those posts, but they are representative of a couple of prevalent viewpoints on this subject.
Im coming from a bit different angle here. Let me cut straight to it: I do not feel comfortable with the motivations behind the marketing of the "B" bikes. I think the wheelsize is being pushed on an unsuspecting market place by one main motivation: money. Yep, I really do not see any other reason behind it that makes any sense.
First of all, there is the historical perspective. It isn't like the "B" wheels haven't had a chance to be exploited for off roading before. There are several examples of where the format has been tried already. I could be wrong here, but my feeling is that 700c mtb had been chosen over that "B" size for a reason. It could have gone either way. The thing is, there were inherent benefits to going to a 700c mtb tire and wheel combination that 650B didn't offer. History speaks but too few are listening. Even the main proponent of this whole she-bang had a say in the early adoption of a different choice in mountain bike wheel size. Why "B" size now all of a sudden? Weird. Something fishy about that to me.
Secondly, the touted benefits of the "B" wheels are all less than what 29"ers give you. There are those that say smaller bikes will be easier to make in "B" wheels. Yeah, well tell that to all the sub 5'5" folks already on 29"ers. It's not like 29"ers can not work, they already do. Yes, the "B" sized wheels should be used for smaller folks, I'll agree with that. In those instances 26 inch wheels should be eliminated altogether for adults. However, it's not likely that a huge, entrenched wheel size is going to give way to a "new" standard for smaller folks. So, the "B" will be relegated to the custom ranks for the most part there.
Some say the "B" sized wheels will be better for long travel/DH/AM applications where 29"ers pose too many design constraints. Oh really? Gee, nobody must be paying attention to what folks like Niner, Lenz, and Intense are already doing with long travel 29"ers. Here's a dirty little secret for ya: It's not that "B" sized wheels will be better in those applications, it's that they are easier to get into production tomorrow. Take for example how easy it is to just slap on a set of "B" wheels and go for a whirl on a bike already in production. Does this click with anybody? You can look like you are providing "big wheeled benefits" with a minor tweakage to your existing 26"er sleds. Hmm...................smells like money to me! Once again, 29"ers are not a problem to use in long travel and the benefits of the bigger wheels is greater.
So, am I against the "B" sized mountain bike wheels? Absolutely not! I think it's a cool idea for some other reasons. I just don't like the ideas being pushed forth as "benefits" for that size wheel. To me the whole 29"er thing came about because the wheelsize worked great for mountain biking. The "B" sized wheels seem to be getting traction for reasons still not seen on the trail. 29"ers were there to try for a few years. There was no money in them. The whole thing took off because it worked and worked well. It took a few years, but that's where it came from. Now they are telling me that the 650B works "even better" for reasons that are not making sense and haven't even been experienced yet? Hmm..................I am a bit wary of the whole thing.
So, Interbike will be interesting if just for that one thing. A real ride on a couple of "B" bikes.
I'll tell ya what I think after that, I can guarantee you that much!