On a long marathon or a technical XC lap, every gram on the rim and any flex under cornering shows up in how the bike tracks. Yarrow wheels are built for XC and marathon racing (not enduro or downhill) with ART asymmetric rims, 25mm deep and 30 to 32mm inside, in 29" and 32" sizes. The Ninefold versions add carbon spokes and our own Onda-M hubs for the lowest weight. Choosing between wheel sizes? Read why 29ers are here to stay, or what 32-inch wheels offer in weight and stiffness. Start with the Yarrow SL29 or the Yarrow SL32.