Lezyne Speed Drive CO2

The Lezyne speed drive CO2 looks like a very nice package for the minimally minded. CO2 pumps don't get much smaller or much lighter. It accepts all threaded cartridges, but only works on Presta valves.

In theory, operating instructions are pretty straightforward: screw cartridge all the way into head, pop on the valve, unscrew half a turn, tyre rock hard in seconds, off you go. I didn't find screwing the cartridge in that easy in the first place and when I did the CO2 came straight out. After trying this twice, once with a Lezyne cartridge and once with another brand cartridge, both time with the same results, I called it a day. I expected that I had a duff one and when the replacement duly arrived it did seal when the cartridge punctured, allowing you to inflate the tyre. Even then, though, it doesn't give a great deal of control and sealing is still a bit hit and miss. I wouldn't want to rely on it.

Another downside of a minimal design like this is that it will freeze to your hands if you're not careful, definitely make sure you're either wearing gloves or you stick your jersey or something in between your hands and the cartridge. Call me a wuss, but I don't trust things under pressure all that much. Above all else, I need two things from a CO2 pump: I need to feel in control, and I need to trust it's going to get my tyre inflated when I need it to. This pump fails on both counts for me. Lezyne's more substantial Alloy Drive is a much better bet.

Verdict

Very minimal, but difficult to operate effectively.