Tire sizes are starting to resemble algebra equations: 26 x 4.8, 27.5 x 2.6, 27.5+ x 3.25, 29 x 2.4, 29+ x 3.0.
But the numbers all add up the same鈥攚ider equals better. From a little extra girth on 鈥渘ormal鈥 tires to the monster-truck treads of fat bikes, bigger tires are becoming the norm for their superior grip and comfort. 鈥淏y increasing tire size, you increase the amount of rubber contacting the ground,鈥 says Chris 颅Cocalis, owner of . 鈥淭hat extra traction gives you confidence.鈥
There are drawbacks to a聽bigger tire, in the form of increased weight and rolling resistance. Finding a happy medium spawned the plus-size trend; three-inch tires on 27.5-inch rims are an optimal compromise between heft and grip.
Pivot Switchblade
That search for an ideal traction-to-weight balance made the ($9,500 as tested; 28.9 lbs.) our favorite. It鈥檚 already an aggressive trail bike, with 135 millimeters of rear travel and a stout 150-millimeter Fox 36 fork, but聽the 2.8-inch聽Maxxis聽Rekon聽tires on this carbon stunner turned the nastiest trails into an easygoing cruise.
Part of the Switchblade鈥檚 success comes from tricks like extra-wide rear hub spacing, which allows for extremely short聽chainstays聽and the resulting poppy handling that鈥檚 rare in such an assertive bike. Then there鈥檚 the hulking 815-millimeter-wide bars, which made steering through rock gardens a snap. The Switchblade also accommodates 29-inch wheels fitted with 2.5-inch rubber, an arrangement that aggressive testers preferred for the added agility and cornering. With all options included, it鈥檚 the best-riding, most versatile mountain bike money can buy.
Three Other Standouts
- The ($4,700 and up; 28.4 lbs.) is one of the most aggressive 29ers on the market, with 150 millimeters of rear travel and a聽banger 160-millimeter fork.
- Though the ($4,700; 27.4 lbs.) is a plus-size model, it puts three inches of rubber on 29-inch hoops for outrageous technical capabilities, making it the only hardtail that can keep up with a full-suspension bike.
- With a pedaling stance as narrow as most standard mountain bikes, the ($3,200 and up;聽24.6 lbs.) pulled double duty聽on snow and summer trails.