If 26 were 29: Mountain bikes and choosing wheels

Gabriel    mountainbikingholidays, Pro Tips     26-Inch wheels, 29-Inch wheels, mountain bike holidays, mountain biking, mountain biking gear, MTB

There is a lot of debate over the size of mountain bike wheels. The current trend has seen people choosing wheels for their mountain bikes and taking the normal 26” standard wheel and increasing it to a diameter of 29” (to be clear, that is an average outside rim diameter with no tire on the wheel). There has been quite a fight as to which system is better on mountain bikes. The fact is they both are: it all depends on what kind of riding you are looking to do and what kind of cyclist you are.

Rollin with 29'ers

The arguments against “29ers” are very strong (industry doesn’t like change – especially if that means buying a new fork and frame to accommodate the bigger wheels), but when the chips (and the wheels) are down, the mountain biker should asses whether or not the switch to larger wheels is a good idea. Bigger wheels on the bike-market means more choice for the buyer, so accept the innovation. Here are a few things to consider when considering a 29-inch wheel purchase:

1. Weight:

Con: Larger rims constitute more weight. There is more metal and as a result it makes the mountain bike heavier. 26-inch wheels are thus essentially lighter.

Pro: Larger rims have more metal in them, but it’s a pretty insignificant weight difference. There are a number of manufacturers who produce tubeless 29-inch rims. Get rid of that inner tube and you get closer to your preferred riding weight.

2. Cornering:

Con: On mountain bikes with larger wheels, it’s difficult to make sharp turns on tight singletrack. When space is an issue in the narrows and you’re traveling at a good pace, a smaller wheel is preferable when making the corner and catching the wheel on an obstacle. When choosing wheels, smaller is better when the track is tight.

Pro: A larger wheel means you have a smaller surface-area contacting the ground. This translates into less friction and improved cornering. Since you have a smaller patch of rubber touching the ground, the wheel handles better in harrowing turns than a smaller wheel does.

3. Size:

Con: Big wheels make the bike seem clunky and out of control. Low branches, rocks and roots are all more difficult to navigate with a bike that seems like a cruiser. 26-inch wheels make the bike more agile so maneuvering up, over or under obstacles is not a hassle.

Pro: The addition of 29-inch wheels doesn’t change the height of the bike, but the bike can feel “longer.” Of course, when choosing wheels you would need another frame (you can’t just “stick on” 29ers), but bigger wheels help cruise over bumps and holes in the ground. The larger circumference means you get a smoother ride over obstacles than you would with smaller rims.

4. The Mountain Biker:

Con: A rider under 177 cm may be at a disadvantage on 29ers. A raised center of gravity means a more dangerous position descending. Smaller riders are better off on a bike with 26-inch wheels primarily because it allows them to get as low as they need to.

Pro: For taller riders (177 cm and above), 29-inch wheels are a benefit. Longer limbs and longer torsos mean the rider can still get a low position on these wheels when descending and cornering (partly because the weight is also displaced by arms and legs fanning off to the side of the bike in descents for example). Therefore, a taller mountain biker should strongly consider the investment in 29-inch rims.

5. The Shatter Factor:

Con: A larger radius rim means the wheel and the fork need to be stiff to prevent them from shattering. That kind of stiffness prohibits the elastic potential of mountain bikes and makes for a stiffer, bumpier, more uncomfortable ride.

Pro: Wheel stiffness depends on the number of spokes in the rim, the material the rim is made out of, double-wall or tripple-wall rims, dish and a number of other factors. Briefly, a 29-inch wheel can be as stiff as you’d like it to be, just as a 26” wheel can. There isn’t any more danger in a bigger wheel falling apart then for a smaller wheel.

About the author

Gabriel Del Rossi wrote 12 articles on this blog.

Gabriel is a professional tour guide and ski instructor. He has mountain-biked most of the trails in the French/Italian Alps and in New England in the US. When not outside, Gabe can be found writing for various on-line publications.

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Related posts:

1. The First Mountain Bikes : Fat-Tyres and Clunkers
2. Mountain bike gear: are tubeless rims the best for your ride?
3. New Bikes: Buying a Mountain Bike

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