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