Are GEAX tires good?
Jessica Cortez
Updated on April 04, 2026
They are super fast rolling, offer great traction, and have held up well so far over roots, ledges, and sharp rocks. If you are a racer and want one tire for both training rides and race day, or if you just want a lightweight trail tire with really low rolling resistance, then these are for you.
Are 650b tires the same as 26?
A 650b wheel is one that’s about 27.5 inches in diameter, when measured from tyre edge to tyre edge. This compares to 26in for a standard mountain bike wheel and 29in for so-called ’29er’ wheels (700c road wheels are also 29in in diameter).
Will 650b fit on 26 wheel?
You’re not out of the woods just because your bike can accommodate 650b wheels and tires. A number of 26-inch forks can fit a 650b wheel, though you’ll need to add rubber bumpers to prevent your fork kissing your front tire, and you may need to limit the rear suspension in a similar fashion.
Can 700C fit on 650B?
That’s where 650B saves the day. With the same diameter as a 700C x 28mm tire, a 650B x 48mm tire can provide all the goods without risking excessive toe overlap.
What does the B in 650B mean?
650b, 700c etc are all old french metric tyre size designations. The “650” denotes approximate outside diameter of an inflated tyre, the b or c refers to width. Originally the French system had tyre widths from a through to e with a being the narrowest.
Is 650B slower than 700C?
On top of that, a 700C tire will have a significantly larger diameter than a 650B tire of the same width. That too has an impact on not just speed but the amount of power required to keep the wheel rolling. At that point, technically the larger diameter wheel and tire will roll faster than a smaller one.
Can my bike take 650B wheels?
You can run a normal 700c up to 38mm – but if you pop on a 650b wheel with a 2.1in tyre, the diameter is pretty similar so you’re not losing anything in terms of your ability to roll over rocks, but you’re essentially just turning a bigger percentage of that diameter into air cushion.
Are 650B wheels smaller than 700C?
700c wheels feature a larger diameter rim and are the standard choice for most gravel riding and racing. 650B wheels have smaller diameter rims that are often paired with bigger volume tires for added compliance and traction.
Will a 700C tire fit a 27.5 Rim?
The two main options are 700c which is standard for road and cyclocross bikes or 650b, known in the mountain bike world as 27.5″. Both wheel sizes come with pros and cons making them suitable for different riding purposes and conditions but in certain respects, the two wheel sizes can be relatively interchangeable.