B'Twin MNP 500 mini-pump

The B'Twin MNP 500 is a well made alloy-bodied mini-pump that's easily pocketed or hidden on the bike but our test model struggled to get bike tyres up to a rideable pressure.

At 22.5cm long the MNP 500 is discreet enough to slip into a jersey pocket but if that's not your thing it comes with a bottle-cage mounting bracket which keeps hold of the pump tenaciously, even when attached to a bumpity bouncity cyclo-cross bike.

As mini-pumps go it's well made with the aluminium body feeling solid in the hand, and the majority of the pump is covered with a soft plastic which keeps it both secure in the frame clamp and easy to grip when thrusting away trying to get air in. The pump is kept locked together in its collapsed state with a simple rubber o-ring on the shaft.

This B'Twin mini-pump is designed to only inflate Presta valves, which keeps both size and weight down thanks to the lack of different rubber internals or extra heads, but that valve hole doesn't come with any locking device so a certain amount of firm dexterity is involved keeping the pump snug tight on the valve. The old thumb-over-the-tyre clamp technique works best here.

The pump only has 13cm of stroke with which to get air in, which isn't a lot. This means you have to get pretty busy when inflating a tube, and as the handle doesn't fold out into a T shape like some other mini-pumps it's not the most comfortable experience despite the rubberized sleeve, especially when it gets to the struggling strokes, which are quick in arriving.

B'Twin claim the pump can reach 8 Bar, which is 116 PSI in old money. That, to be fair, is rather deep into the realms of wishful thinking if our experience is anything to go by.

It doesn't take long before pumping the MNP 500 became a chore. At 100 strokes your bicep might start to twinge and the tyre will still be worryingly squishy. At double that amount of pumpage a standard 700x23 tyre is still going to be what only the very polite would call firm and it took at least 300 exhausting strokes with our test model to get the tyre anywhere near some sort of just-about-get-you-home pressure of 60PSI.

It's possible that the 500 in the name refers to the number of strokes you have to wrestle through to get a tyre up to a reasonable pressure. You might need to neck a gel at about 400 but push on through to the magic 500 and the tyre gets up to a more confident 80PSI.

You might need a recovery lie down in the gutter after all that though. Even by mini-pump standards this B'Twin requires a real effort. And in my opinion it's not worth the effort because there are better pumps out there.

You could get enough air into a tube with the B'Twin pump until your arm got bored and then top it up to a decent pressure with a burst from a C02 canister as some people like to do, but that means taking two pumps on a ride, which kind of negates the point of taking a petite pump that doesn't take up much room.

The MNP 500 is hard work and not something you'd want to use by the roadside, either in the misery of the rain or the sweat of the sun.

Verdict

Small, solid feeling mini-pump but very hard to get a decent pressure