Your bicycle tyres need constant regular topping up. Naturally they will loose pressure over time. There is nothing wrong with that. We recommend you to pump them up once a month at least, using a good pump with a gauge that allow you the read the air pressure its been inflated to.
The manufacturer recommended inflation range will be etched on the sidewall of your tyres and it will look like this “Inflate to 50 to 75 PSI” – pounds per square inch.
Since most good bike shops are kind enough to leave a pump by the door to be used for free, you don’t need to buy a pump, but is a good idea to have one at least for emergencies.
Below is what I used in the past and I know it is good.
The leave at home
Topeak Joe Blow Max series – This is a sturdy steel barrel floor pump that I found at most bike shops I walked into in London. It will inflate both Presta and Schrader valves, so it is a good idea if you have different bikes and can be purchased for around £30. You won’t be able to take it with you as this is too big.
Lifeline Essential – I had this pump for a bit until I decide it to sell it. It has an amazing price (£15) it does the job properly (it has a dual head, so it will inflate any tyre). The problem for me it feels like it wasn’t enough for the amount of beating my pumps are submitted to when I am working. I am pretty sure, it is a great pump to have in the house to be used once or twice a month.
The easy to carry
The Lezyne Micro Floor Drive series – There will be several options here, high volume, high pressure, with or without gauge. I would go for the high volume, without a gauge because honestly it is not a very accurate gauge. Other than that it is a great mini pump that I had for about 5 years until eventually it fell apart due to over use with my trainee’s bicycles. Had I only use on my bicycle, I am pretty sure it would be still good even after 10 years. Expect to pay about £30 to £40 depending on the model.
The Topeak Morph series – This is the pump that currently lives in my pannier. The model I have is the Morph Turbo. It is incredible. Accurate gauge. Easy to operate. Push a lot of air at each stroke. The only criticism I have here is since it is made of plastic, this is the kind of pump that needs gentle operation. Whereas with the Lezyne Micro Floor I wouldn’t mind lending it to someone, this one nobody is allowed to operate except myself. Between £20 and £40, depending on the model you pick.