Mountain Gear

Tech FAQ: Before Buying 650B

A reader asks tech guru Lennard Zinn if a 650B bike doesn't work out, can 26-inch wheels work on the rig instead?

Dear Lennard ,

I just read your column about the 650B bikes: Tech FAQ: 650B or not to be?

In that column you say that is probably okay to mount 650B wheels in a regular 26-inch, checking obviously that the fork works. Well, what about the other way around? What can I lose?

I´m going to explain myself better: I’m looking forward to buying a 650B bike. But my question is if it doesn’t work for me with those wheels, can I put a regular 26-inch wheels to that bike? What can happen?

I don’t want to buy a good 650B bike to take it for a couple of rides and realize that is not for me and sell it losing a lot of my invested money as happened with my 29-inch bike. I´m 5-foot 7 and those big wheels are definitely not for me, but I love some sensations that the 29er gave me and I also like to try new things. That’s why I think the 650B is for me.


Dear Pablo,

The brakes (assuming the same disc rotors) and the suspension travel will not be a problem when making the switch from 650B wheels to 26-inch ones. However, your bottom bracket height will drop by around a centimeter (0.5 inch). This could give you pedal clearance problems where you could end up clonking your pedals a lot on technical climbs. You should check that you have abundant pedal clearance before buying that 650B bike. Or use the biggest tires you can find on the 26-inch wheels.


Technical writer Lennard Zinn is a frame builder (, a former U.S. national team rider and author of numerous books on bikes and bike maintenance including the pair of successful maintenance guides “Zinn and the Art of Mountain Bike Maintenance” – now available also on DVD, and “Zinn and the Art of Road Bike Maintenance,” as well as “Zinn and the Art of Triathlon Bikes” and “Zinn’s Cycling Primer: Maintenance Tips and Skill Building for Cyclists.”

Zinn’s regular column is devoted to addressing readers’ technical questions about bikes, their care and feeding and how we as riders can use them as comfortably and efficiently as possible. Readers can send brief technical questions directly to Zinn.

Follow Lennard on Twitter.