FSA QR-20 Self-Extracting Crank Bolt – M17, Left Arm, 24 mm Alloy Cranks
The FSA QR-20 self-extracting crank bolt fixes the left crank arm of FSA MegaExo 24 mm alloy cranks such as the FSA Comet: an M17 crank bolt with blue thread-lock and a black aluminium M27 × 1.0 self-extracting cap, together in one piece.

Why this bolt?
One part for the left arm. The bolt and the cap belong together and come as one unit, so you replace the whole fixing of the left arm in one go.
Self-extracting cap. The cap threads into the crank arm and also works as a puller, which helps when the arm has to come off the spindle.
Torque on the bolt. The tightening torque of 38–41 N·m is printed on the bolt, so you always know how tight it should be.
Blue thread-lock. The bolt thread comes with thread-locking compound, ready to fit.
Who is it for?
- Owners of FSA MegaExo 24 mm alloy cranks. Such as the FSA Comet, who need to replace a lost or damaged bolt or cap.
- Workshops. That service FSA MegaExo cranks on belt-drive and gear-hub bikes.
Specifications
| FSA part number | 390-0022000010 (QR-20) |
|---|---|
| Product | Self-extracting crank bolt with cap, left arm |
| Bolt thread | M17, with blue thread-lock |
| Tightening torque | 38–41 N·m (printed on the bolt) |
| Cap thread | M27 × 1.0, marked LH and AL |
| Material / colour | Aluminium, black anodised |
| Fits | FSA MegaExo 24 mm alloy cranks, e.g. FSA Comet |
| In the box | 1 self-extracting crank bolt (M17 bolt with M27 cap) |
Frequently asked questions
Is the FSA ML038 crank bolt the same thing?
No. The FSA ML038 is a plain crank bolt without the cap and a separate product in our shop. This one is the self-extracting bolt with the M27 cap.
Does it fit carbon cranks?
FSA uses different bolts and caps for some carbon cranks. Send us a photo of your crank if you are not sure.
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, and its MegaExo system with external bearings and a 24 mm spindle is one of the most widely used crank and bottom bracket platforms on mountain, gravel, trekking and urban bikes. FSA parts are fitted as original equipment by many bike brands, including our own Booda Bike belt-drive bikes.
