A humble bicycle pump is an essential tool for bike maintenance, allowing you to add air to your tyres quickly and easily. It's recommended that you do this every two weeks to maintain the quality and speed of your ride. Bicycles are at their best when tyres are at their ideal pressure, as this helps them roll smoothly and reduces the likelihood of punctures. You can find a wide range of bicycle pumps on eBay, from brands including Lezyne and Topeak.Track pumps
Track pumps are also known as floor pumps, and belong in the home of every cyclist. A track pump will quickly inflate your tyres to the correct pressure level with a minimal amount of effort, leaving you with the energy you need for your ride. They're too large to carry with you, however, they're very durable and reliable.Hand pumps
Standard hand pumps, or mini pumps, are compact, light and portable. Hand pumps can easily be fitted to your bike's frame, or carried in your bag or pocket. Although they are not as fast as track pumps, their small size lends them to being more portable. Some hand pumps have foldable bases, creating a semi-track pump which combines performance and portability.C02 pumps
C02 pumps are small, single-use cartridges which can be used to inflate your tyres within seconds. A standard 16 g cartridge can inflate a 700 x 23 c tyre to roughly 100 psi, which is enough for a mountain bike or a road bike. In the absence of valves, you'll need to guess the tyre pressure. It's a good idea to carry a few with you, as you can only have as many attempts as you have cartridges. Bike tyres need re-inflating regularly, as they can lose approximately 10 psi every week.