Most of you know, and no shame if you don’t, that 700C is the dominant wheel size in the modern bike world, and the biggest of the top three. The other two are 26-inches, and 650B. It sounds like two languages, but when you translate them all to rim diameters, as people rarely do but always should, it goes like this:
700C = 622 millimeters
650B = 584 millimeters
26-in = 559 millimeters
A simple but good way to think of them (but not when communication matters, as when buying wheel parts) is large, medium, small.
700C = Large
650B = Medium
26-inch = Small
The 700C wheel makes the most sense in these circumstances:
On our bikes, 700c show up on all sizes of the Roadeo, because it’s a sporty-club-racer bike; and on the touring and off-road sized frames that accept the Big wheel with no compromises. The Hunqapillar 54 and larger; the Atlantis 58 and larger; the Bombadil 60 and larger (although we coulda done it on the 56, as well, but what the heck).
- Racing against other 700c riders, and with teammates who also ride 700C wheels. If you need a new wheel, you’ll be able to get one.
- On any bike that doesn’t require compromises in frame design or clearance (which, of course, is part of frame design, but I want to emphasize the clearance part) by using the Big wheel.
- Big mountain bikes. The bigger wheel rolls over bumps better. If you doubt this, consider the difference between riding over a pothole or a driveway lip with a skateboard (which has small wheels, don’tcha know), compared to riding over the same thing with a bike with a much bigger wheel on it. The difference between Big, Medium, and Small bicycle wheels isn’t as dramatic as that, but the dramaticness makes the point, and the same physics (is that what it is?) applies.
What’s a “29’er”?It’s just a fat 700C tire. It’s a term in the same language as 26-inch, the normal mountain bike size. Any 700C wheel that measures 28-inches or bigger is a “29’er.” So, if you prefer metric, a 700x45mm tire and up qualifies.
It is common to see small frames with 29ers. Bike makers who make ‘em are trying to ride the trendiness of the giant wheel, but it’s misapplied to a small frame.