Q: Suppose I buy a new 27-inch-wheeled bike and hate it. I really like the idea of the mid-sized wheels, but you never know. The new wheels might clash with the color scheme of my shorts. If I just slap on an old set of 26-inch wheels and tires, am I good to go, aside from the occasional pedal whack?
—Tim, who has commitment anxiety

MBA: You could probably live with a 27 bike converted to a 26er, but chances are it would not be all that fun. There are so many factors that come into play. Does the bike have slightly longer stays for wheel clearance? If so, it will have a longer wheelbase than you need with 26-inch wheels. It shouldn’t be too much of an issue with the steering because you are changing both wheels.

The bottom bracket height is a bigger deal than you think. We recently tested some Shimano pedals side by side, and we noticed clearance issues (we kept hitting rocks) with the pedal that was just slightly fatter. It was a shocker.

Finally, we don’t think you are going to hate 27-inch wheels. When we took the KHS 609 Carbon test bike out for photos, the rider we used (who had not ridden a 27) wanted to buy the bike on the spot. Even if you hate the bike, you shouldn’t have much trouble trading it in.