Azur CO2 Replacement Cartridges 38g are the big-volume option for riders running large tyres. A 38g threaded cartridge holds well over twice the gas of a standard 16g, so you can get a high-volume mountain bike, fat bike or wide gravel tyre back up to riding pressure with one cartridge instead of fumbling with two.

They pair with any compatible threaded inflator head and fit easily in a pack or frame bag. Grab a single for your next big ride, or stock up with a larger pack if you ride often. The more you buy, the lower the price per cartridge.

Who are these CO2 cartridges for?

Mountain bikers, fat bike riders, bikepackers and gravel riders on wide tyres who want fast trailside inflation without pumping for minutes on end. Also handy for tubeless riders who need a strong blast of gas to help seat a stubborn tyre bead.

Who is this not for?

Not the right choice for road bikes or narrow tyres. A 38g cartridge holds far more gas than a skinny road tyre needs, so you’d be wasting most of it and risk over-inflating. Road riders are better off with our 16g or 25g threaded cartridges.

Why we love it

One cartridge, one big tyre, job done. When you’re out on the trail with a 2.4″+ tyre, a 16g cartridge often won’t cut it, and carrying two is a hassle. A 38g gets you rolling again quickly with one hit.

Hot tip!

CO2 escapes faster than regular air through inner tubes. After using a cartridge to get home, it’s worth deflating and reinflating your tyre with a floor pump later for longer-lasting pressure.

Item specs

• Brand: Azur
• Product type: Threaded CO2 replacement cartridges
• CO2 capacity: 38 grams per cartridge
• Cartridge type: Standard thread (3/8″-24 UNF)
• Compatibility: Suits most threaded CO2 inflator heads
• Use case: High-volume tyre inflation, MTB, fat bike and wide gravel tyres
• Material: Steel cartridge with compressed CO2 gas
• Inflator head required: Yes (sold separately)
• Quantity options: Packs of 1, 5, 10 or 20 cartridges