I'd say it must have a good sturdy build and should be stable.
It must have a good pressure control and display; it should have a proper pressure range.
It should have a good connector with detachable/replacable plugs.
It should have a long hose, so you're not too close to the bike and make full control strokes on it.
bicycles.stackexchange.com/users/13517/Max
A double-sided chuck for both Presta and Schrader valves, with sturdy lever "Universal" chucks don't work as well and aren't as durable (IME, so not the most expensive), while the type that involve switching bits inside are one thing for carrying on the bike when space/weight is at a premium but another for workshop use.
bicycles.stackexchange.com/users/7309/Chris H
When you use the pump to inflate a tire the pump body gets hot.
This heating up results in a temporary expansion of the body itself.
If the cylinder and the base are made of two different materials (cylinder made of metal, base made of plastic) this thermal cycling can lead, in the long run, to loss of air tightness and less efficient pumping.
In the worst case the pump can simply break.
So I personally prefer full metal body pumps.
Additionally, it is good if it has: versatile head to fit different valves pressure gauge with psi and bar reading large base to be stable during usage fair hose length
bicycles.stackexchange.com/users/30865/L.Dutch - Reinstate Monica
The ability to shove pressurized air into a tire :-)
Seriously, it is very hard to discern minor quality difference between pumps.
Best advice is: Look for and read reviews.
Get one that looks and feels sturdy and relatively heavy.
Avoid the cheapest 1/3 of the available models.
bicycles.stackexchange.com/users/24228/Argenti Apparatus
It may be a long way down the road, but look for a pump who manufacturer offers rebuild kits for their older models.
Park pumps definitely have rebuild / service kits, as do Zefal and Silca.
However the extra cost of the premium brand might be weighed up against the value.
bicycles.stackexchange.com/users/19705/Criggie
A Stable Base Floor pumps stand on the floor and you hold your foot on one side for stability.
So a base that allows the pump to tip over is less useful.
A falling pump could smash the pressure gauge, or worse, subtly uncalibrate it)
This is more likely if the gauge is up the top.
bicycles.stackexchange.com/users/19705/Criggie
Don't fuss over this.
No-one makes a floor pump that only does low or high-pressure tyres.
I've never seen one that didn't have adapters for both types of valve, and YOUR bicycle only has one type, so you won't be constantly changing over.
Yes, a floor pump is less work than the type you clip to your bike frame, but isn't part of the reason you cycle to get exercise?
Sure, treat yourself to a floor pump.
No need to go mad though.
bicycles.stackexchange.com/users/19532/Laurence Payne
It must have a valve between the cylinder and the hose, or else you will never build up a high pressure like 5 bar.
The pumps that are also suitable for car tires have such valve, because the valve on the tire is opened by the chuck.
Cheap bicycle pumps that depend on the tire's own valve are useless, you are just pumping up the dead volume of the hose.
Unless you add a second valve..
bicycles.stackexchange.com/users/37261/StessenJ
There are so many options, mainly because of the own-brand alternatives. So how do I choose a good floor pump? What should I look for?
What makes a good floor pump?
bicycles.stackexchange.com
<pump>
bicycles.stackexchange.com/questions/53991
bicycles.stackexchange.com/users/26707/Pablo
A good floor pump should be stable and sturdy. It should have good pressure control and a pressure display, as well as a good connector with detachable plug and long hose. It also needs a versatile head to fit different valves. It is recommended to avoid the cheapest pumps. Reading reviews before buying is recommended. It should be sturdy, compatible with different valves, with a good pressure display and quality parts. A long hose allows you to stand away from the bike while pumping. Look for good reviews and manufacturers who offer rebuild kits. Avoid the cheapest options.
It should be sturdy, compatible with different valves, with a good pressure display and quality parts. A long hose allows you to stand away from the bike while pumping. Look for good reviews and manufacturers who offer rebuild kits. Avoid the cheapest options.