Gear: Big wheels rule

The revolution is over — and big wheels have won. The “29er” mountain bike, which first appeared on the scene a decade ago with monster-truck tires 3 inches taller than the age-old 26-inchers, now dominates the market. It’s easy to see why: The bike makes you faster and safer, gaining more momentum and floating better over sand and rocks. This year, the demand’s so hot for huge hoops that some companies don’t even sell 26ers anymore. Others have started experimenting with different-size big wheels, like the 650B, a “27.5er” (reviewed below) that touts faster speed with sharper steering. At the recent Handmade Bicycle Show in Sacramento, one company even rolled out a 36er — a cruiser with 3-foot-diameter tires. A mountain-bike version can’t be far behind.

Dream machine

Cannondale Scalpel 29er Carbon 2: Ultra-light, high-end, carbon-fiber dual-suspension, do-it-all race-recreation bike with unique one-sided Lefty fork.

Likes: A super bike — fast, light (24 pounds), solid-feeling and quick handling with great components (SRAM X9 front derailleur, Shimano XTR rear). Climbing is aided by a rare handlebar-mounted suspension lock-out button, adding convenience and safety over a normal fork-mounted lock-out, which requires reaching down a foot to twist a dial. A 39-tooth chainring on the SRAM 20-speed drivetrain (not the common 36) lets you pedal all-out on long descents and the flats without spinning out. The one-piece seat-chainstay has flattened tubes that add suspension flex but eliminate wasteful lateral wiggle.

Dislikes: Although a great climber, it could handle the super-steeps better with a 22-tooth small front chainring (like the Specialized below), instead of its 26-tooth.

Price: $5,300. (800) 245-3872; https://www.cannondale.com

All-round star

Specialized Stumpjumper FSR Comp Carbon 29er: Plush cross-country trail bike with carbon-fiber mainframe and aluminum rear triangle.

Likes: Great all-round speed, climbing and handling, with lots of cushion over big bumps with 130mm of suspension travel. A good components package includes SRAM’s 20-speed drivetrain, X7 and X9 front and rear derailleurs, and a rear Fox shock with Autosag, which makes setting up the bike for your weight simpler than usual. Solid as a rock, it uses good low-end gearing (a 22-tooth front chainring with an 11-36 rear cassette) to provide great leverage on steep inclines. It feels lighter than its 28.8 pounds, which is still light for a 29er. A similar all-aluminum Stumpjumper Comp 29er is $2,700.

Dislikes: The 36-tooth front chainring is too small; I found myself spinning out on long descents and the flats. It needs a 39-tooth, like the Cannondale.

Price: $4,100. (877) 808-8154; https://www.specialized.com

Bare-bones brawler

Felt Nine Trail 29er hardtail: 24-speed aluminum-framed bike with front suspension only.

Likes: If you had to use one bike for everything and didn’t have a lot to spend, this stout, bare-bones bike would be it. The components, including a 24-speed Shimano Alivio drivetrain, 100-mm SR Suntour fork with lockout, and mechanical (not hydraulic) disc brakes, won’t impress the local bike geeks, but they are functional and effective for real mountain biking, riding around town and even commuting. In fact, all 29er hardtails are fast on pavement due to the large diameter and momentum. The small knobbies of the Geax AKA tires are particularly fast on blacktop and hard-packed fire roads. Weight: 32.34 pounds.

Dislikes: Those small mini-knobbies did not get good traction on steep trails.

Price: $699. (949) 452-9050; https://www.feltbicycles.com

New size, new paradigm?

Jamis Dakar SixFifty B Comp: Plush aluminum-framed dual-suspension bike and unusual 650B wheels that split the difference between 29ers and 26ers: a diameter of 27.5 inches.

Likes: Great balance, speed, handling. This in-between 650B wheel size, currently only offered by two companies (Jamis and Dominguez Hills-based KHS), seems to live up to its billing as the best of both worlds: Most of the speed, momentum and roll-over-everything capability of a 29er, coupled with the flick-ability and quick acceleration of a 26er. It doesn’t feel like a steroid freak, like 29ers tend to do at first — but it made me ride like one. I don’t know yet if I would take this over a 29er, but I am sure of one thing: That the 650B will kill the 26er for good. Includes 130mm of suspension travel and a 30-speed drivetrain with middle-brow Shimano SLX derailleurs. Weight: 32.2 pounds.

Dislikes: The 650B’s odd-size tires and inner tubes are hard to find right now.

Price: $2,700. (800) 222-0570; https://www.jamisbikes.com

Wallack is coauthor of “Bike for Life: How to Ride to 100” and “Barefoot Running Step by Step.” roywallack@aol.com