Quick release vs thru-axle: everything you need to know

Two fastening philosophies

Quick release (QR) and thru-axle (TA) serve the same purpose: securing your wheel to the frame or fork. But their design and performance are radically different.

Quick release (QR) uses a 5 mm diameter skewer that passes through a hollow hub and locks with a cam lever. Invented by Tullio Campagnolo in 1927, it's the historical system. You'll still find it on entry to mid-range road bikes and older mountain bikes.

Thru-axle (TA) is a threaded rod, 12 mm in diameter (or 15 mm at the front on some standards), that screws directly into the frame or fork. The hub is sandwiched between the dropouts with zero play.

Standards you need to know

Quick release (QR)

• Front: 9 mm x 100 mm (diameter x spacing)
• Rear: 10 mm x 130 mm (road) or 10 mm x 135 mm (MTB/trekking)

Thru-axle (TA)

• Front road: 12 x 100 mm
• Front MTB standard: 15 x 100 mm
• Front MTB Boost: 15 x 110 mm
• Rear road: 12 x 142 mm
• Rear MTB standard: 12 x 142 mm
• Rear MTB Boost: 12 x 148 mm
• Super Boost: 12 x 157 mm (DH and some enduro)

The Boost standard (110/148 mm) widens the hub spacing to allow more symmetrical spoke lacing and wider tires. It has been the norm on virtually all mountain bikes since 2018.

Why thru-axles have taken over

Stiffness. A 12 mm axle is incomparably stiffer than a 5 mm skewer. With disc brakes, lateral forces on the wheel are massive. A QR can flex enough to cause disc brake rub.

Repeatable alignment. With a QR, the wheel can be slightly offset every time you reinstall it — you know the problem of disc rub after putting the wheel back. A thru-axle centers the wheel identically every time.

Safety. A poorly tightened QR can open while riding. A threaded thru-axle cannot accidentally come undone.

Torque specifications

Thru-axles must be tightened to torque. A common mistake is going "as tight as possible" — you risk damaging the frame threads.

• Front thru-axle: 10-15 Nm (typically 12 Nm)
• Rear thru-axle: 12-16 Nm (typically 14 Nm)
• Quick release QR: no torque value, but enough clamping force to leave a mark on your palm

Always check your frame manufacturer's specifications. Some carbon frames require lower torques (8-10 Nm).

Can you convert a QR frame to thru-axle?

No. The frame dropouts are structurally different. A QR frame has open-ended dropouts, while a TA frame has closed bores with threading. Modifying the frame structure is impossible on aluminum and inadvisable on carbon.

However, some hubs offer conversion kits. For example, a TA hub can be used with a QR adapter (losing stiffness). The reverse is rarely possible.

How to choose for a new bike

• Recreational road / budget gravel: QR still works, but disc brakes make TA practically mandatory
• Performance road / gravel: thru-axle 12 x 100 / 12 x 142
• MTB: Boost thru-axle (15 x 110 / 12 x 148) — the universal standard
• DH / extreme enduro: Super Boost 12 x 157

Use L'Atelier to find the exact standard for your frame or fork — just ask with your brand and model.