Air Shocks

How does an air shock work?

Air pressure in the main chamber supports the rider's weight, replacing a metal spring. A negative air chamber helps the shock break away smoothly at the top of the stroke, and the damper cartridge controls compression and rebound speed, just like in a coil shock.

Why choose air over coil?

Air shocks use a pressurised air chamber as the spring, making them significantly lighter than coil alternatives and adjustable without swapping hardware. A shock pump and a few minutes are all it takes to change the spring rate, which is why they dominate everything from trail bikes to enduro race bikes.

What do volume spacers change?

Adding volume spacers — small plastic tokens — reduces the air volume in the positive chamber, making the spring curve more progressive. This means the shock ramps up resistance as it compresses further, helping prevent bottoming out on big hits without making the initial stroke feel harsh. Most riders benefit from 1–3 spacers depending on riding style and frame design, and spare tokens are sold alongside other rear shock spares.

Which air shocks are worth looking for?

The Fox Float X2 is the flagship, with a four-way adjustable damper offering excellent support and sensitivity, and it comes as standard on high-end enduro bikes. The Fox Float DPX2 is trail-focused, lighter and simpler than the X2, with a three-position lever plus rebound adjust. The RockShox Super Deluxe Air pairs the Charger damper platform with the DebonAir+ air spring, making it a strong performer that's easy to service, while the Cane Creek DB Air uses a twin-tube design with the most adjustment range of any production shock. The RockShox SIDluxe is XC-specific: lightweight, with a firm lockout for climbs.

What should I check buying used?

Inflate to your riding pressure and leave overnight — a slow leak means the air can seals need replacing, which is a cheap service but worth factoring into the price. The shaft must be smooth and free of scratches, as any damage here causes seal wear and leaks. Compress the shock slowly: it should feel smooth and controlled, and if it collapses with no resistance the damper needs a rebuild.

When was it last serviced?

Air shocks should be serviced every 50–100 hours for the air can and annually for the full damper, so ask the seller when it was last done. A recently serviced shock with receipts is worth paying more for, and an unknown service history on any rear shock should be priced with a rebuild in mind.