CO2 Inflators
Browse CO2 inflators for sale in the UK, from bare push-on heads weighing under 20g to trigger-controlled inflators with an insulating sleeve. A 16g cartridge takes a 700x25c road tyre to roughly 100psi, while a 29in mountain bike tyre needs a 25g cartridge to reach a usable pressure. Aimed at racing, commuting and anyone who would rather not spend five minutes with a mini pump on a cold verge.
How does a CO2 inflator work?
The head pierces a sealed cartridge of liquid CO2 and routes the gas through a Presta or Schrader chuck into the tyre, filling it in two or three seconds. The two designs worth separating are the plain push-on head, which empties the whole cartridge in one go, and the control-valve or trigger type, which lets you meter the gas and stop partway. Lezyne Control Drive and Genuine Innovations inflators are common examples of each approach. The cartridge gets cold enough to frost and stick to skin as it discharges, which is why insulating neoprene sleeves are sold with most kits.
CO2 inflator or a mini pump?
CO2 is a one-shot fix: two cartridges, two punctures, then you are walking. A hand pump is slower and will not reach race pressure easily, but it never runs out. CO2 also does not stay put — the gas diffuses through butyl far faster than air, so a tyre inflated with a cartridge will be noticeably soft within a day or two. Plan to let it down and re-inflate with a proper pump when you get home, and many riders carry a small pump alongside cartridges rather than instead of them.
Which cartridges fit — threaded or non-threaded?
Threaded cartridges screw into the head on a standard thread and are the more common size, sold in 16g, 20g and 25g. Non-threaded cartridges are cheaper and need a head designed to clamp rather than screw, so the two are not interchangeable — check which your inflator takes before buying a box. Size choice follows tyre volume: 16g for road, 20g for gravel and cyclocross, 25g for mountain bike tyres, and two 16g cartridges will not fill a 2.4in tyre as well as a single 25g.
Do CO2 inflators work with tubeless sealant?
They will seat and inflate a tubeless tyre, but the cold gas can cause some latex-based sealants to clump or partially set, which reduces how much of it stays liquid and able to seal the next cut. If you run tubeless and use a cartridge at the roadside, check the sealant when you get home and top it up. For seating fresh tyres at the bench, a tubeless charger or air tank gives you a repeatable burst of ordinary air instead.
How much should you pay?
The inflator head is a small, cheap part; the ongoing cost is cartridges, which are usually bought in packs of five, ten or twenty and get much cheaper per unit in the larger boxes. A metal-bodied head with a control valve costs more than a plain plastic one and is worth it if you regularly inflate to a specific pressure. For home use it is a poor buy full stop — a floor pump with a gauge does the same job for nothing per use, and cartridges are best kept for the saddlebag.