Gear Guy

Do bigger wheels on a mountain bike make a difference?

What do you think of the newer mountain bikes with 29-inch wheels? I'm thinking of upgrading my 1989 Fisher Hoo Koo E Koo for something more roadworthy, but that can still take the abuse of dirt trails. I was thinking of getting a cyclocross bike, but perhaps a 29-inch wheeler might be more suited to the kind of riding I want to do. Booker Kensington, California


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The 29-inch wheels now on some mountain bikes (Gary Fisher makes several models) have two supposed advantages: One, you can use 700c tires on them (the road bike standard these days, referring to a 700-millimeter outer diameter), an advantage if you want to use a mountain-type bike for touring or recreational riding on asphalt. Two, the bigger wheel doesn’t hit obstacles like roots or rocks at such a severe angle as the traditional 26-incher, so in theory can roll over the obstacle more easily.

But, is a 29-inch wheel “better” than a 26-inch wheel? Hard to say. Certainly, the 26-inch standard is arbitrary, simply being the original size of the fat tires when mountain bikes were first pioneered back in the 1970s. But the 29-inch size—really just another way of identifying a 700c wheel—is in itself quite arbitrary, its origins to some degree lost in the misty past of cycling. No one seems to have done any real empirical study as to what the ideal wheel size would be. I’m willing to buy into the idea that a 29-inch wheel rolls better in some instances, something that might be particularly useful for downhill riding. But it’s also going to be heavier than a 26-inch wheel, perhaps meaning greater fatigue on long rides, plus lesser acceleration.

That said, Fisher makes a nice-looking bike called the Dual Sort 129 ($1,430; that has 29-inch wheels, a nice mix of Shimano LX and XT components, disc brakes, and a Manitou shock. It would be a MASSIVE upgrade over your Hoo Koo E Koo.