Salsa Vaya 650B Conversion (Overview)

In case you haven’t noticed, the bicycle industry is touting the 650B wheel size as the proverbial next big thing. They’ve even given it a catchy nickname–27.5″–so folks will know where it fits in the MTB wheel-size hierarchy (namely, right between 26″ and 29″). What’s interesting though, is that 650B wheels are nothing new. The French constructeurs of the 1940‘s and 50’s favored 650B wheels, and some of Tom Ritchey’s earliest MTBs were designed around the 650B wheel size.

This tween wheel size has not gone unnoticed by tinkerers and gearheads (including yours truly). Many riders found that they could fit wider, more comfortable tires into frames and forks designed for 700C (and 27″) wheels without increasing the effective wheel diameter. My own interest in 650B conversions centered around increasing the off-road capabilities of my 700C-wheeled Salsa Vaya. Box-stock, the Vaya has clearance for 700×42 tires (1.9″ on 26″-wheeled models), but I found myself wanting a little more meat for steep, rocky¬†terrain. After taking a few quick measurements, I concluded that the Vaya was a good candidate for a 650B conversion.

Here is a breakdown of the Vaya’s conversion process:

  • Wheels and tires
  • Drivetrain and gears
  • Miscellany

Stay tuned for the results (both good and not-so-good), caveats, and my overall impressions of the converted bike.

10 thoughts on “Salsa Vaya 650B Conversion (Overview)

  1. So….I’m curious about 650B wheels. I’m needing to understand what advantages they bring to a bike and why is the industry pushing 650B. Why aren’t they called 650c wheels? I have a 55cm Vaya with 700c wheels. Love the thing. I have sold off other bikes now that I own a Vaya.

    • Thanks for the reply.

      Wheel/rim sizing can be extremely confusing. The late Sheldon Brown published a very comprehensive list of wheel/rim sizes, which you can find here. Sheldon explains the A, B, and C nomenclature on this page.

      So why 650B/27.5? Many claim that it combines the best features of 26″ and 29″ (aka, 700C) wheels. Proponents will tell you that 650B/27.5 wheels spin up quickly like 26″ wheels, but still retain the smooth(er) ride of 29″ wheels.

      I’m a huge fan of the Vaya. I’ve ridden mine thousands of miles, both on- and off-road. However, the widest 700C tire that will clear the frame/fork has less (air) volume than a compatible 650B/27.5 tire. Think of it this way–the “height” of the tire is like suspension. If you have more height (air), you have more suspension. There is, however, a limit on how tall the tire can be before you run out of clearance. When you shrink the rim’s diameter, but keep the overall tire diameter (height) the same, you’re increasing the volume of air, which yields more cushion and flotation.

      • Okay, that’s interesting. One of the aspects of the tires I’m riding is that they have a very low amount of rolling resistance. I keep them at 70 psi. I love how fast I can be with them. Is this possible with 650B tires?

        • There are some very fast-rolling 650B tires available. The Grand Bois Hetre is both fast and smooth-riding, but doesn’t have much in the way of tread. Most of the 650B/27.5″ knobbies have a max pressure of 50 psi or so. The deep tread/knobs will slow you down more than the lower pressure, though.

  2. After looking around the web I now get the impression that 650B is for unpaved situations? I just may build a wheel set for my Vaya!!!! I’ll save the 700c Conti Travel Contacts for touring and commuting. :-)

    • Right now, the emphasis is on unpaved use. Small builders/companies such as Kogswell and Rawland advocated 650B for paved and “country bike” use.

  3. I am patiently waiting for your “good and not so good” results. I’m right on the edge of buying a Vaya but have been waiting to see your report on the 650b aspect as I would be really interested in doing this with the Vaya. What are the not so good aspects of it? Pedal strike? Tire fit? Thanks for any info on it!

    • Right now, there are very few sub-2.00″ knobbies being offered in the 650B/27.5″ size. I spoke to some of the tire companies at Interbike, and I hope to be receiving some narrower (but still dirt-capable) tires in the coming weeks. If your wheels are perfectly true/dished, and there’s no mud, there are some suitable tires available. But, if you get caught in a sudden rainstorm, and there’s mud, expect to lose some paint due to the wider tires’ side-knobs.

      Pedal strike is actually lessened with the 650B/27.5″ wheels. The overall height of a 700×32 SOMA New Xpress is approximately 0.25″-0.50″ less than a 2.1″-2.3″ knobby. If you encounter pedal-strike (say, on step-ups), it will be due to the Vaya’s relatively low BB.

      Stay tuned…

  4. Pingback: Salsa Vaya 650B Conversion Project (Wheels & Tires) | GRAVELBIKE.com

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