Topeak AirBooster Nano With 16g CO2

Topeak's AirBooster Nano with 16g CO2 cartridge is a basic inflator that was a bit hit-and-miss on Presta valves though it works well on Schraders. But as our best bike pumps and CO2 inflators guide shows, there are lots of options when it comes to inflation.

A CO2 inflator seems a no-brainer for quick puncture fixes on the road, especially in the winter when you don't want to keep your riding buddies waiting. Topeak sent us its AirBooster Nano as a carded pack that includes a gas cartridge and what it calls a 'shell' to put that in. We'll bring you more on that in a moment...

> Buy now: Topeak AirBooster Nano with 16g CO2 for £12.99 from CJ Performance Cycles

My main requirements for a CO2 inflator are that they are simple to use – no complicated routine to remember that might result in a failure – and are controllable for preventing over-inflation. Lastly, a good seal twixt inflator and valve is essential, to avoid the undesirable outcome of the entire canister being discharged into the air instead of the tyre.

The AirBooster Nano adaptor is a single piece of CNC-fashioned aluminium, knurled for grip where needed and weighing under 10g on our kitchen scales. At one end it's threaded to fit a standard cartridge thread, the other to fit a Schrader valve, though for Prestas it's a push fit only.

The airtight seal is made using an internal rubber ring and this will be subject to wear with use as it is pushed down over the Presta valve head and stem with its various threaded surfaces. That could compromise the seal in time.

In my view a screw fit is the more reliable way of making a good seal. On the other hand, I've used screw-on inflator heads for Presta valves that have removed the valve core when I've unscrewed them, with catastrophic results (I'm looking at you, Lezyne!). If you are using tubeless tyres with Prestas then you will certainly have removable valve cores; in that case a press-fit like the Nano Airbooster is probably a safer bet.

> Video: Learn the easy way to change a tubeless tyre

However, I found it took a bit of trial and error to be sure I was using the Topeak just right. In particular, you need to get a feel for how far to loosen the valve core head before pressing on the adaptor – too far and the valve core was inclined to get pressed down by the Airbooster's internals, letting even more air out.

On the other hand, you need to be sure the adaptor is pressed down firmly over the stem to ensure the seal engages properly. This kind of 'vague' operation matters less with tools you use every day and get a feel for how they work best; but with something kept for emergencies like this, I really want it to work first time, every time and I wasn't confident of that.

Inflation is achieved by screwing the cartridge all the way into the adaptor to puncture the end, then backing it off a half-turn or so. If you find you don't need a whole cartridge, you can stop the flow by tightening it into the head again. I thought this might allow me to save the remaining gas for the next job, but Topeak advises you to completely discharge the cartridge after inflating your tyre.

Inflation was very quick (it was too quick to time!) on a 25mm tyre, but I struggled to get the tyre up to more than 85psi before the cartridge ran out of puff. Topeak's 'Inflation Suggestion Sheet' reckons on 100psi for a 25x700c tyre, but then adds helpfully, 'Actual inflation pressure may vary'. We have a guide on how to choose the best tyre pressure if you’re not sure.

As supplied, the Nano AirBooster has a rubber collar that sits between the gas cartridge and the inflator. This is there for storage, simply to prevent you screwing the canister too tightly into the head and discharging it accidentally. It's exactly the kind of small part that's going to get lost in the long grass but it's not super-critical.

The gas cartridge itself seems fairly standard. Topeak's website tells you to use only its cartridges – and why wouldn't it? I suppose there may be some variability in the length of the threaded necks that might result in you accidentally screwing the cartridge in too far, though I tried a couple of different makes without problems.

> Learn how to fix a puncture

The other item in the pack is the plastic sleeve, which Topeak refers to variously as the 'CO2 Shell' or the 'CO2 Sleeve'. The instruction leaflet tells you to 'use the CO2 Sleeve to protect your hands during inflation'. The instructions on the back of the card say: 'Please wear gloves to protect your hands during inflation.'

The rapid discharge very quickly freezes cartridge, adaptor and stem and I can vouch that the sleeve itself will not stop your fingers from frosting. In fact, it was even more useless than that, because on trying to screw the cartridge fully into the head I found the sleeve was turning but the cartridge wasn't, despite the rubber band that's supposed to make a snug fit. If you're using a 25g cartridge (recommended for 29ers and gravel tyres), it won't fit in this sleeve anyway. I thought Topeak could save a couple of quid by leaving it out.

Value and rivals

You can buy the Nanobooster head separately for around £13, so a penny under £17 RRP means you're adding £4 for the cartridge and the rubbery/plasticky bits. With a pair of Topeak's own 16g cartridges coming in at £9, that's not too bad.

Birzman's E-Grip CO2 Inflator uses a neoprene sleeve instead of the plastic one supplied by Topeak and worked well when Shaun tested it, but at £17.99 it's a little dearer than the Topeak.

At the more deluxe end of things Pro Bike Tool's CO2 Inflator comes in at £19.98 – but with no cartridge included. It employs a screw fitting, but, sure enough, Steve Williams found it had a propensity to remove your valve cores.

Overall, I thought this Topeak offering was okay, if you're confident you can remember how to use it 'just so' in the field: Best to take a spare gas cartridge, just in case. Oh – and protect your hands with gloves, not the supplied sleeve.

Verdict

A rather 'vague' fit on Presta valves made this a bit hit-and-miss, but it's light and simple