If you’re wondering how to choose between 650b and 700c for your next gravel bike, you’re not alone. All of the Niner gravel bikes can accommodate either 700c or 650b wheels and tires. In fact, we have expanded our selection of stock 4- and 3-star builds with the 650b wheel size.
But which gravel bike wheel size is right for you? Let’s dive in to explain the difference between 700c and 650b gravel bike wheels.
To put it simply, 700c wheels have a larger outer diameter (622mm) compared to the outer diameter of 650b wheels (584mm). The 700c wheel size has been overwhelmingly popular and the accepted standard for road bikes for more than a century. But the 650b size, once popular long ago, is making a comeback in some circles (get it?).
The larger 700c wheel size generally gets credit for lower rolling resistance, better rollover capability, and carrying more momentum. You might also make a case that the larger wheels generally just feel faster. These arguments in favor are quite similar to the benefits of 29er mountain bike wheels.
There is a place for 650b, however. With a smaller rim diameter, the rims are often a little wider and offer space to support a larger width tire. A larger volume tire, in turn, offers more grip and more bump absorption. Furthermore, because the rims are smaller diameter, they’re closer to the hub and the spokes are shorter. This results in a stronger, stouter wheel that is popular for loaded touring and bikepacking.
You can almost consider the different gravel bike wheel sizes like those on passenger cars (we know, bikes are better than cars, but the analogy is useful). A fast sports car has large wheels with low profile tires for speed, efficiency, and precise handling. A Jeep has smaller wheels and bigger tires for grip, clearance and compliance over uneven terrain, and durability on rough surfaces.
There are other things to consider. Small riders using small frame sizes might prefer 650b wheels to minimize “toe overlap,” when the rider’s foot on the pedal can contact the front wheel during low-speed turns due to the small, compact frame geometry.
Depending on what you’re doing with your gravel bike, you’ll want to choose the wheel size that best suits your needs. Most riders are going with 700c these days, and your Niner gravel bike can fit really wide (50c) tires on those big wheels. But if your Road Less Traveled includes extra rough terrain, loaded touring, bikepacking, or any other situation where Jeep-style gravel riding might be found, consider the 650b.
And if you can’t decide, never fear! All our bikes accommodate BOTH sizes, so you can easily swap in the future.
Whatever you end up choosing 700c or 650b, have fun riding those gravel roads!