Italian brand Alchemist showed off their latest lightweight hoops, this time with a somewhat more subtle design than past offerings.
The new 29er Clincher RR is a race-ready mountain bike wheel that comes in at just 1,245g per set. That’s with properly wide rims (26mm internal), thru axle hub options and 24 spokes per wheel. Much of the weight savings comes from rims that register at just 325g each, minimizing rotational weight.
They’re laced up with Sapim CX-Ray spokes to their own carbon-and-alloy hubs…
A more subdued design allows for lighter weight, but they’re still very strong and stiff thanks to the curved “V” shape and reinforced spoke sections.
Hubs are a beautiful blend of carbon fiber and machined metal, with the non-drive side flowing smoothly into 6-bolt brake mounts.
An asymmetric rim keeps spoke tension and angles balanced. They recommend seating the tire first on the right side where there’s a more abrupt bump up to the bead seat, then working the other side on.
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At Frostbike, we saw the new Kuroshiro Enso685 fat bike rims that reinvented the way tubeless works. It’s an impressive design and worth clicking to read even if you’re not into fat bikes.
Now, there’s a 29+ version that’s 50mm wide and puts Airex in the zig zag channel to make it laterally stiffer. They say that helps with the larger diameter and the additional side stresses a 29+ puts on a rim.
Airex is an extremely low density foam that weighs little more than air yet adds a high amount of stiffness to a structure when sandwiched between layers of, say, carbon fiber. They didn’t have a weight on this one as it’s an early prototype, but if it’s anything like its ~400g fat bike sibling, it’ll change the game.
The Zirconium debuted in late August with a unique, asymmetric aerodynamic rim profile. You can get all the tech details and cutaway images here, but we thought we’d throw in a couple photos.
No matter how we hold it, it’s hard to see the concave shape of one side of the rim. It’s made this way to allow for an offset spoke bed to balance tension for a disc brake hub without skewing aerodynamics from one side to the other.
