IRC is making more and more of a push into gravel, promising a solid presence at this year’s Dirty Kanza, which brings out the hardcore gravel racers. They introduced the Marbella and Boken gravel tires over the past couple years for those riders. But for roadies just dipping their toes into the dirt, they now have something for them, too.

IRC Marbella X Guard 700x26 and 700x28 gravel road bike tires

Let’s say you just wanna give dirt roads a try but don’t wanna invest in a new bike. Cyclocross tires are too big to fit in most road bikes, especially if you’re still running rim brakes. So, IRC is introducing the Marbella file tread in 700×26 and 700×28 sizes.

IRC Marbella X Guard 700x26 and 700x28 gravel road bike tires

Both get their tubeless ready construction with puncture protection. Claimed weights are 295g and 330g each, look for them to hit the market by summer.

IRC Aspite Pro aero road bike tires with aerodynamic sidewall grooves to reduce drag

The IRC Aspite has been in their line for a while, but it’s getting a refresh. The design now has a grooved texture over the entire surface. While that makes sense on the usual tread cap section, it’s the sidewalls that are interesting.

IRC Aspite Pro aero road bike tires with aerodynamic sidewall grooves to reduce drag

IRC Aspite Pro aero road bike tires with aerodynamic sidewall grooves to reduce drag

The tires use a small trip line, presumably to help the air stick to the side and roll smoothly onto, then off of, the rims. Which is what they say those grooves on the sidewall are for, much in the same way dimples on a golf ball work, to reduce turbulence.

IRC Aspite Pro aero road bike tires with aerodynamic sidewall grooves to reduce drag

They say those fins reduce drag by 4%. It’s not just aerodynamics, though, the tread and their special RBCC (rice-bran based) rubber compound offer great grip. About the only thing it’s missing is their tubeless tech, making it one of the few tires in their line that’s not tubeless ready.

IRCbike.com

6 COMMENTS

  1. More options for bikes with narrower tire clearance. Nice. I hope these sell well.

    Aspite looks good too. Seems like a ‘faster’ version of the original herringbone-tread Panaracer Gravel King. I wonder if it’s also offered in a 28 or 30 mm width?

  2. Reduces drag by 4%?? As compared to what? And at what wheel speed? And at what crosswind angle? And how does it actually affect overall vehicle drag?

    On a skinny road tire, the deep rim is still a problem as it exposes substantial surface area to wind speeds nearly twice the vehicle speed at the top of the wheel, where wheel drag is greatly magnified against propulsive counterforces delivered at the axle. A small drag force at the top must be countervailed by a much larger propulsive force at the axle, making upper wheel drag much more important than any comparable frame drag force.

    As pictured above, the surface area of the deeper rim is similar to that of the skinny tire. Better is to utilize a shallow rim with a skinny tire for reduced total exposed surface area at the top of the wheel altogether, but then making spoke drag more critical. Then by using swiveling aero spoke tailfins to maintain laminar flow over the spokes even at higher vehicle speeds and under any crosswind condition, minimizes overall vehicle drag while having exposed upper wheels. (Best is to shield the upper wheel from headwinds instead.)

    Legal for Ironman, our aero tailfins also provide greater safety with unmatched crosswind stability, becoming particularly effective as vehicle speed rises. The more spokes on the wheel, or the faster you cycle, the more one needs aero spoke tailfins over round spokes.

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