Problems from an over-inflated tyre
Tyres can be blown off the rim if the pressure is too high and this can occur in a few different ways.
Don't ever use one of those air lines at a petrol station for inflating tyres. They pump air in too quickly for bicycle tyres. Half a second too much and you could add 20psi too much. Besides, the roller style gauges are renowned for being totally inaccurate.
Don't do as I did recently. I fitted a new tyre onto my daughter's bike. Pumped it up to the recommended 105psi and left it in the sun. Ten minutes later there was a loud BANG just like someone firing a gun. The tube burst and threw the tyre off the rim. Could have been caused by the tyre not being seated properly, although I did check it while I was inflating the tyre. I'll never know.
Lastly, imagine your tyre is pumped up to the recommended pressure. It's a summers' day and you are freewheeling down a long steep hill. Naturally you apply the brakes gently to keep a steady speed. The friction of the pads on the rim can heat a rim and inner tube very quickly and thereby increasing the air pressure drastically. I once knew someone who experienced this frightening accident. What made it worse was it was the front tyre that exploded off the rim; which inevitably caused the tyre to instantly get jammed in the brake and launch the cyclist in flight over the handlebars. Not recommended.
Problems from under inflated tyres
- Getting punctures - under inflated tyres have more tyre in contact with the road and all the debris that's there and consequently increasing the chance of getting a puncture. Hard tyres often seem to flick bits of gravel to the side.
- Dents to the rim, rim going "out of true" - caused by a very soft tyre bottoming out on a kerb, stone or maybe a pothole
- Losing control - if you have a soft tyre on the front wheel and hit a bit of rough road surface, it can easily lead to losing control if you're going fast
- Increased tyre wear - as simple as that
- More effort needed - you'll use more energy
- Taking the trouble to ensure your tyres are at the correct pressure will probably cause you to notice other things on the tyre. This could include bits of glass working their way into the tyre, sidewall damage etc.
Track pumpsHaving a track pump makes it so easy to bring your tyres up to the correct pressure. With 700c tyres typically running at 100psi or more it's hard work to achieve this with an ordinary hand pump (like the kind you could carry on your bike). With a track pump it's simple and needs hardly any effort.
Probably worth me commenting on this particular track pump and why it's important to buy one with care. This is a few years old now, probably no longer sold and therefore no need for me to review it properly. The main down side is that it feels a bit flimsy. When you have your feet holding it firmly to the floor and you're pumping hard, make sure you pump straight down and not slightly sideways. This is because it feels a bit flimsy, especially where the barrel joins the base. It's not all bad. The gauge is fairly accurate, it pumps efficiently Specialized have given it an ergonomically well designed handle and the tube is generously long. It works with Schrader (car type) and Presta valves.
Other track pumps worth "tracking" down
SKS Airkompressor 12.0: not bad but still a little flimsy.
One23 Pressure+: works okay but cheap and cheaply made
Pedros Prestige: more expensive at £40 but durable. Performance is adequate
Topeak Joe Blow Max HP: another short hose but effiicient
Leyyne Sport FD: worth getting for good all-round performance and a quaint wooden handle. Easiest to switch between value types.
Blackburn Air Tower 1: not bad at all for one at the cheaper end (£24.99) and a good brand