The definition of what road bikes are capable of is rapidly changing, and that means tire changes, too



Panaracer Gravel King: $50

New from Panaracer, the Gravel King is a reasonably-priced all-around tire that's available in 23mm, 25mm and 28mm (270 grams). The tire utilizes a special cord casing and ZSG (or zero slip grip) compound that's a combination of natural and synthetic rubbers that are claimed to make the tire both supple and durable. Tread has subtle bite, but is not overly aggressive, so you'll still be able to spin efficiently on tarmac.

More info: www.panaracer.com



Michelin Pro4 Tubular Service Course/Michelin Pro4 Comp Service Course: $121/$75


Ten years removed from its last road tubular offering, Michelin has launched a new 290tpi purebred race tire (23mm or 25mm, latex tubes). So far so good. This is the tire the Hincapie Development cycling team won the overall team title at early April's Redlands Bicycle Classic. Of course Michelin also makes lots of raceable clincher tires, including the revamped Pro4 Comp Service Course, a 150tpi version with lowered rolling resistance and puncture protection (23mm).

More info: bike.michelinman.com



Challenge Gravel Grinder: From $38

Best known for their cyclocross tires (we love the Fango), Challenge is diving ever deeper into the burgeoning gravel game with its new Gravel Grinder tire. The vulcanized rubber version (pictured above) is designed for truly rough road riding (think Dirt Kanza) where durability and tread bite are paramount. This 38mm clincher is available in 60tpi or 120tpi, has an integrated double puncture protection system, and extra volume for better float and comfort. The 60tpi version weighs 425 grams and runs $38; the 120's are 408 grams and $46. Challenge will also be launching a 36mm tubular and open tubular version later this year.

More info: www.challengetech.it



Schwalbe One: From $80

Why call it the One? Because Schwalbe say this 127tpi road-race-ready rubber is the fastest tire it's ever made. It's even manufactured in a separate facility built exclusively for this top-end offering. The One is available in standard (23mm, 25mm, 28mm), tubeless (23mm, 25mm, 28mm) and tubular (22mm, 24mm, 26mm, 28mm). Performance gains, Schwalbe says, come from its new triple compound that's faster rolling but still has good grip and puncture resistance.

More info: www.schwalbetires.com



Kenda Kountach Endurance/Kenda Kommando X-Pro: $40/$45


Tire giant Kenda rolled out a pair of new tires. The Kountach Endurance has an 120tpi casing with single layer Kevlar protection across the sidewall and dual Kevlar protection across the tread surface. It's available in 23mm and 25mm sizes, with a 28mm coming by the end of the year. For the bog hoppers, Kenda has changed up the Kommando cross-specific tread pattern, increasing knob height and increasing tread spacing. The renamed Kommando X Pro comes in 33mm and is designed as an all-around tire that can be run in one direction for hard conditions and the other for wet. And of course it's tubeless ready.

More info: www.kendatire.com