Hollow CNC’d cranksets are how several brands compete with carbon fiber weights and stiffness, and now FSA is joining the party with their new KFX crankset. The KFX moniker replaces K-Force as the top offering, and these are the flagship item showcasing their manufacturing prowess.
By machining the insides out of two halves, then bonding them together, they create a box section design that resists flex…and gravity. The crankset has a claimed weight of 530g with 30t direct-mount chainring.
The arms are forged first, then CNC’d into shape. They’ll come in 170mm and 175mm lengths, use a BB392VO alloy spindle, and work with any of FSA’s direct-mount chainrings. Choose from 30/32/34/36/38 tooth counts, and they say all of them work with SRAM and Shimano 11- and 12-speed drivetrains.
We saw prototypes of these when we visited their factory last year, here’s a couple pics showing how the two halves are slotted together.
Small keys ensure perfect alignment during assembly. The construction method has been used by Cannondale for ages with their SiSL cranks, and more recently Hope Technology has come up with their own unique take on the process.
FSA PowerBox alloy MTB cranks & more
They’ve added an alloy crank arm option for their PowerBox power-meter crankset to bring the price down a bit. It’s a solid cold-forged 6061-T6 alloy arm, also available in 170-175mm lengths. Chainring options are 30-36, and weight is as low as 840g.
The arms use a scalloped design with a bit of machining on the ends to save weight.
The new Gradient alloy arms are aimed at the all-mountain/gravity rider with stronger, thicker, yet come in at just 628g with a 30t chainring. These get smaller options all around, with 28t to 38t chainrings and 165/170/175mm arm lengths. Also 11- and 12-speed compatible, and also using the wider BB392EVO spindle length…which means they’ll fit just about anything except fat bikes, but you may need spacer rings for some bikes.
FSA brings integrated cockpits to mountain bikes
The FSA ICR concept was first shown a couple years ago, and has since gained adoption on several major and minor brands’ road bikes. The concept pairs a handlebar and stem with a specific upper headset cup design. That means frame manufacturers have to be on board, as the headtube has to be designed around that larger diameter, but adoption seems to be moving along.
Now (or soon), mountain bikes will have a similar option.
The design runs cables, wires and hoses into the handlebar, which feeds it directly into the stem. Underneath the stem are holes that feed all of those into slots in the headset cup and spacers, which then let it into the frame.
More FSA KFX carbon cockpit options
The KFX Stem uses a 3D forged-then-machined alloy base that’s wrapped with carbon to form a composite structure that’s both light and strong. It has an aggressive +/-12º bend, catering to the XC crowd.
The KFX Flat handlebar uses a reinforced and offset center area to maintain a perfectly flat top section. Claimed weights start at 160g for the 700mm width. Reinforcements at the lever/shifter and grip mounting areas ensure that light weight doesn’t mean fragile construction.
There’s also a riser bar option that gets internal routing for future compatibility with that ICR stem system. Surprisingly, it comes in even lighter with a claimed weight of just 155g for 700mm. There are 760mm widths for both bars, too.
The KFX carbon seatpost rounds out the collection with a 0mm setback and dual bolt fine-tuning clamp design. It has a one-piece continuous carbon fiber construction, weighs in at 181g, has 350mm and 400mm lengths and comes in 27.2 and 31.6 diameters.
New Gradient 35mm all-mountain handlebars
The Gradient all-mountain group gets a new 35mm clamp diameter bar and stem. The bar uses their carbon-composite construction, weighting in at 250g with a 20mm rise and 800mm width. The stem is 3D forged-then-machined alloy and weighs in at 123g for the 35mm length (50mm also available).