Berd has made a name for itself with its unique PolyLight spokes and lightweight, high-end wheelsets. Today, the brand introduces the new Sparrow50 Gold gravel wheelset, which it claims is the lightest production 50 mm gravel wheelset on the planet. With 30 mm-wide, 50 mm-deep carbon rims and Berds Polylight vibration-damping spokes, they also state that the Sparrow50 Gold is the fastest and smoothest gravel wheelset available today.Thats a bold claim, but the self-proclaimed bike nerds at Berd (Bike + Nerd = Berd) are backing it up with science, of all things. Not only are they launching the Sparrow50 Gold wheels today, but theyre also laying out the engineering framework in their white paper, including the equations, physics, and field data behind their claims. Along with that, Berd is also launching a free finish time calculator so riders can compare the effect of wheels and tire widths on their ride times.Sparrow50 Gold DetailsThe Sparrow50 Gold wheels are made with super aerodynamic 50 mm deep carbon fiber rims in 700c (29) or 32 diameters. The rims have a 30mm internal width, a hooked bead, and a 4mm-wide bead top to reduce the chances of pinch flats. The 30 mm width is compatible with tires from 40 mm to 60 mm wide, and has been tunnel-optimized at 45-55 mm with Schwlabe G-One RS Pro tires. According to Berd, the new Sparrow50 rim and wheelset is 14.3% more aerodynamic than the standard Sparrow in wind tunnel testing.Of the tires tested, Berd says that the 45mm Schwalbe G-One RS Pro had the lowest drag and was the fastest on smooth gravel. However, through their finish time modeling, they say that 55mm tires can be faster on rough gravel, despite having slightly worse aerodynamics.Wind tunnel tested to be 14.3% more aerodynamic than the standard Sparrow.Talon ESL-R HubsAt the center of the Sparrow50 Gold wheels are Berds Talon ESL-R hubs, which the brand calls its fastest gravel hub yet. These hubs use Berds patented hook flange design with Equal Spoke Length (ESL) technology. By varying the hook flange widths, every spoke, front and rear, is the same length to keep wheel building and maintenance simple.The Talon ESL-R rear hub uses a dual-sprung 36-tooth ratchet for quick engagement and a Tri-Coat aluminum freehub, which is available in SRAM XDR, Shimano Microspline or HG, and Campagnolo N3W. The front hub is convertible between 12 and 15 mm axles with tool-free end caps, and the wheels are available in standard gravel (12 x 100 mm / 12 x 142 mm) and Boost (12 x 110 mm / 12 x 148 mm) spacing with a centerlock brake rotor interface.The Talon ES-R hub and Polylight spokes.Berd SpokesTying those aerodynamic rims and hubs together are Berds unique Polylight spokes. Berd tells us that its spokes have earned two Olympic Gold Medals and more than 50 UCI World Cup cross country podiums over the last two seasons, making them the winningest XC mountain bike spokes in the world. According to the brand, the viscoelastic spokes damp vibration, reducing feedback and fatigue, but also smoothing the ride and enhancing efficiency.In fact, along with the more easily measurable variables of aerodynamic drag and mass, they believe the Berd Spokes dissipation of high-frequency vibration contributes to lower rolling resistance compared to metal spokes. You can learn more about it in Berds white paper, but they claim that independent third-party testing by John Karrasch showed a 5-watt savings at 30 km/h from vibration damping alone.Berd is based in Hopkins, MN, where each Sparrow50 Gold wheelset is hand-laced, then precision trued by TRUDI, the brands automated wheel truing system.WeightAccording to Berd, the 1,298-gram weight of the 700c (29) wheelset is the lightest production 50 mm gravel wheelset on the market. That weight goes up to 1,541 grams for the 32 size.WarrantyThe Berd Sparrow50 Gold wheels are covered by a lifetime warranty against manufacturing defects. Additionally, they are backed with lifetime crash replacement if you damage your rim while riding, youre covered under our free crash replacement program.White Paper and Finish Time CalculatorAre you a bike nerd interested in all of the physics, equations, and data behind Berds spokes and performance claims of the new Sparrow50 Gold wheels? Berds white paper lays it all out for you to see. Check it out here.Berds finish time calculator is also live on the Sparrow50 page of the Berd website, down near the bottom of the page. According to Berd, The model accounts for aerodynamic drag, rolling resistance, and the vibration-induced losses that Berd spokes uniquely reduce. Results are intended for comparative purposes only the calculator uses simplified assumptions for rider aerodynamics and does not account for elevation, drafting, or variable pacing.Screenshot of the Finish Time CalculatorSparrow50 Gold SpecsWheelset Weight (w/out rim tape or valves):700c, 29: 1,298 g (600 g front, 698 g rear)32: 1,541 g (718 g front, 823 g rear)Internal Rim width: 30 mmExternal Rim Width: 38 mmRim Depth: 50 mmRim Material: Carbon FiberWheel Size: 700C (29) or 32Hubs: Berd Talon ESL-RFront Spacing: 12 x 100 mm, or 12 x 110 mm (convertible to 15 mm)Rear Spacing: 12 x 142mm, or 12 x 148 mmFreehub: SRAM XDR, Shimano Microspline, Shimano HG, or Campagnolo N3WBrake Rotor Interface: CenterlockSpokes: 24 Berd PolyLight spokesNipples: Sapim Aluminum Double Square LockTire Compatibility: 40 to 60 mm (1.50 to 2.35), tubeless-readyMax Tire Pressure: 60 psi (4.14 bar)Weight Limit: 280 lbs / 127 kgWarranty: Limited Lifetime Warranty and Free Crash ReplacementBerd Sparrow50 Gold: Pricing and AvailabilityIf youre interested in the fastest and smoothest gravel wheels available today, itll cost you. The 700c / 29 Sparrow50 Gold wheels retail for $2,395, and the 32 version goes for $2,495. The 700c wheels are in stock and ready to ship, and the first 50 orders get a set of Schwalbe G-One RS Pro 45mm tires. The 32 wheels are available for preorder with an estimated ship date of 9/21/2026. Head to the Berd website to learn more or pick up a set.berdspokes.com

We come off a week with stage races such as the Arctic Race of Norway, the Czech Tour, and a subdued Volta a Portugal, plus a WorldTour classic in the ADAC Cyclassics Hamburg. These events stirred the individual standings but barely shifted the UCI team rankings. The headline change sits near the...

Yesterday, we wrote that the supporting ecosystem around 32-inch wheels is beginning to catch up. Today, theres another fairly significant piece to add to the puzzle: an actual bike you can order.Mosaic has unveiled the GT i55 32, a handmade titanium gravel bike designed around 32-inch wheels. And the Boulder, Colorado, brand is making its intentions pretty clear: this is, in its words, "not a concept bike."Thirty-two-inch wheels are quickly becoming the bike industry's biggest new trend. We saw a host of bikes, wheels and tyres at Sea Otter, followed by perhaps the highest-profile example yet at Unbound Gravel, where defending champion Cam Jones and ultra-endurance racer Robin Gemperle raced Scotts RC Gravel 32-inch prototype. But Scott made it clear that its bike was a "pure prototype," stating that it "will never be released on the market."Mosaic, meanwhile, is going the other way. The GT i55 32 will debut at this weekends MADE bike show in Portland, Oregon.Mosaic isnt the first brand to move beyond the prototype stage, nor is it the only 32-inch bike headed for consumers. Stinner has already shown its Refugio 32 with pricing attached, BTCHN has been preparing its Bandito for production, and Salsa has said 32-inch Fargo framesets will go on sale this summer, with complete bikes to follow later in the year. Mosaic stands out in that its made-to-order platform is available from launch. A Batch Built option will be added later.x"The new GT i55 32 platform wasnt simply designed to generate conversation around a new wheel size. Its not a prototype destined to disappear after a trade show," Mosaic insists. "Instead, it represents Mosaics commitment to 32-inch wheels as a legitimate performance platform."More than simply squeezing bigger wheels into a gravel bike(Image credit: Mosaic Cycles)Larger wheels bring some compelling theoretical advantages. Compared with a 700c wheel running an equivalent-width tyre, the shallower angle of attack should help it roll over rocks, holes and generally rough terrain more easily, while the larger wheel size is also claimed to carry momentum more efficiently.But there are compromises. Bigger wheels increase stack and wheelbase, stretch chainstays and can create toe-overlap headaches particularly as frame sizes get smaller. Theyre concerns Cycling Weekly has looked at in depth in previous coverage. "...A new wheel standard only matters if its benefits arent limited to the tallest riders in the field," Mosaic states and tackled the aforementioned limitation as "an engineering problem rather than an unavoidable consequence of the wheel size."For starters, the brand's designers decided to design an entirely new platform from teh groun up rather than modifying one of its existing gravel bikes.The frame uses a bent seat tube and relatively compact 440-445mm chainstays to tuck the rear wheel beneath the rider. A 3D-printed titanium yoke creates clearance for tyres up to 55mm (2.2"), while still accommodating a standard gravel chainline and chainrings up to 46 teeth.The axle standards do move into mountain bike territory, with a 148x12mm rear and 110x15mm front.(Image credit: Mosaic Cycles)And then theres the forkMosaic says one of its biggest headaches was finding a fork that would allow the geometry it wanted without pushing the front of the bike too high.So it made its own.The result is a new 32-inch gravel fork under Mosaics new Zero Components name, with a 445mm axle-to-crown measurement and 60mm offset. The former is intended to keep the front end down, while the latter helps Mosaic achieve its desired steering geometry while creating more toe clearance.Mosaic says the combination of its shorter fork, increased offset, compact rear triangle and offset seat tube helps make the platform work across a wider range of rider sizes.And because these bikes are being offered through Mosaics custom programme, geometry can also be tailored to the individual rider.You can actually buy this one(Image credit: Mosaic Cycles)Mosaic is rolling out the GT-1 i55 32 in two initial versions:Fully integrated: The high-end option gets fully internal brake routing, a T47 bottom bracket and a choice of Mosaics standard paint layouts, with pricing starting at $8,250.Semi-integrated: The second option offers semi-integrated brake routing via Cane Creek HCR, a T68 bottom bracket and Mosaics Titanium Ghost finish, and starts at $5,000.Both come with rider-specific custom geometry.More information can be found at mosaiccycles.com.

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