Or do you? To be honest, I'd never given much thought to a carbon saddle alternative until recently, when a passing comment from a bike shop mechanic raised my figurative eyebrow and set me on a path to prove whether all-carbon-everything is, in fact, a necessity.
Let's start with a basic premise: Carbon fiber is lighter than traditional steel alloys and, when used as part of the rail and/or shell construction of a bike saddle, adds a subtle change in flex along with weight reduction.
It can also add anywhere from $125 to $200 to the total cost of your saddle. I set out to determine if I could tell a cost-worthy difference between my existing women's specific saddle, the very popular Fizik Arione Donna, and the Donna 00 carbon equivalent.
Fizik Arione Donna
Shell: Carbon Reinforced Nylon Wing Flex
Weight: 189 g
Dimensions: 285x147 mm
Fizik Arione Donna 00
Shell: Composite Carbon 00 – Wing Flex/Twin Flex
Rail: Carbon braided 7x9 mm
Weight: 169 g
Dimensions: 285x147 mm
Although the saddle dimensions are exactly the same, the advantage on paper goes to the Donna 00 thanks to 20 g in weight savings and the added benefit of Fizik's Twin Flex construction, which combines two layers within the shell for a multi-directional combination of strength and comfort.
In person, however, there are two main differences to note. First off, the Donna 00 is not equipped with Fizik's integrated clip system, a real disappointment for brand loyalists who love their line of saddle bags and rear lights. Fizik's decision to exclude the clip system is understandable given that carbon saddles are generally intended to be a minimalist design appropriate for racing, but it still meant stowing my tire-changing materials in my jersey pocket. Secondly, there is no pressure relief channel on the Donna 00, although there is some built-in relief on the underside of the saddle.
The rest of the Donna 00's differences come in the shell and rail, where an outer sleeve of braided carbon fibers form a tube filled by unidirectional carbon fibers to create the perfect trinity of strong, light and stiff. The non-carbon version employs Fizik's proprietary K:ium rail system (no slouch in and of itself), which uses a metal alloy and tubular design to achieve an 8 percent weight reduction over titanium and a high strength-to-weight ratio. While these differences are mostly unnoticeable to the naked eye, carbon rails generally reduce the overall weight of the saddle and dampen vibration that would normally fatigue a rider.
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