FSA SL-K Carbon Crank Arm Set – 170 mm, Direct Mount
The FSA SL-K Carbon Crank Arm Set is a pair of 170 mm carbon-fibre crank arms with a matte UD carbon finish and a direct mount interface for single-ring (1x) builds – supplied without chainring or belt sprocket, so you choose the ring or the Gates Carbon Drive sprocket your bike needs.
SL-K crank arms at a glance
| Model | FSA SL-K carbon crank arm set, left and right arm |
|---|---|
| Manufacturer code | CKM-OS8330/DM/86 (as printed on the supplier's packaging label) |
| Series | SL-K |
| Crank length | 170 mm |
| Material and finish | Carbon fibre, 50% matte UD carbon, black |
| Graphics | SL-K, black and silver |
| Ring mount | Direct mount |
| Intended use | Single-ring (1x) drivetrains |
| Chainring or sprocket | Not included |
Why direct mount?
No spider, no chainring bolts. The ring or sprocket mounts straight onto the crank arm: fewer parts and nothing that can work loose.
Free choice of ring. Fit a direct mount chainring for a single-speed or 1x chain drive, or a Gates Carbon Drive direct mount sprocket for a belt drive.
Easy to change later. Want a different gear ratio? Swap the ring or sprocket and keep the cranks.
Who is it for?
- Belt-drive builders. Who want carbon arms under a Gates Carbon Drive direct mount sprocket.
- Single-ring builders. Setting up a single-speed, gear-hub or 1x bike with a direct mount chainring.
- Riders upgrading from aluminium. Who want carbon-fibre crank arms with a matte UD finish.
Frequently asked questions
Is a chainring or belt sprocket included with the FSA SL-K carbon crank arms?
No. The set contains the left and right crank arms only. Choose a direct mount chainring or a Gates Carbon Drive direct mount sprocket separately.
What does direct mount mean on a crank?
On a direct mount crank the chainring or sprocket bolts or locks directly onto the drive-side crank arm instead of onto a separate spider. That saves parts and makes it quick to change the ring.
Are these crank arms for a single ring or for a double crankset?
They are intended for single-ring (1x) use. They are not a double or triple crankset.
Can I use the carbon crank arms with a Gates Carbon Drive belt?
Yes, with a Gates Carbon Drive direct mount front sprocket. Gates belt drives run without lubrication.
About FSA
FSA – Full Speed Ahead – has made bicycle components since 1993 and moved into cranksets and chainrings in 1995. FSA introduced the compact road crankset in 2004. In its catalogue FSA describes the SL-K line as a combination of low weight, strength and advanced technology for serious riders, and FSA parts are fitted as original equipment by many bike brands.