It’s a topic of hot debate among those that consider themselves hard core cyclists. To many tyre pressure is all about marginal gains; the speed improvements between 100psi and 110psi or what suits the specific gravel surface being ridden. Couple this with detailed analysis of tread patterns and things can get picky really quickly and way out of the range that most regular commuters need to worry about. Unless you commute on a aerodynamic time trial bike in a skin suit….in which case, as you were.
However, there are some aspects of tyre pressure that are of great importance to regular cycle commuters, here’s what you need to know.
What is Tyre Pressure?
Tyre pressure is a measure of how much air is inside the inner tube on you bike. This is direct corollary of how inflated, or hard or soft, your outer tyre will be.
Every tyre has a range that it should be inflated within. This will be printed on the sidewall of the tyre. It will say something like ‘100 psi MAX’ or ‘inflate to 50-85 psi’.
Tyres meant to be run at very high pressures are designed to minimise contact with the road and therefore be as fast as possible. They often have a very smooth surface as there is no need to for nobbles. Low volume, skinny road tyres are a good example of this.
Wider, nobblier tyres tend to be designed to have more contact with with ground and therefore be softer. However, this increases drag on the road and means you have to put more effort into riding on tarmac.
Why is correct pressure important?
Not only will having the correct tyre pressure make riding easier, it will also help prevent punctures.
For riding on roads, it is generally best to have your tyres at their maximum pressure, regardless of tyre type. This will make it harder for bits of glass and stone to penetrate and puncture them. It will also limit pinch flats. These are punctures that occur when the inner tube gets trapped by the rim of the wheel when going over bumps or rough ground. For example, going over a curb or average lovely London road pothole.
What can you do?
The easiest thing to do to keep your tyre pressure good is by regularly pumping up your tyres. It seems obvious to some, but in the last few years I have been surprised by the number of people who buy a bike and don’t really realise that they require any kind of attention.
When I used to work at Brompton, we used to get people coming back for their post sale checkup 2 months after taking it home and they hadn’t pumped their tyres once. The worst one was someone riding around with 36psi in both tyres. Brompton tyres have to be between 100-120psi.
A track pump with a pressure gage is one of the best accessory purchases you can make, after a lock and lights. If you don’t want to buy one, every bike shop has one you can use and there are some other public ones dotted around.
Generally tyres need toping up once a week if you ride regularly. If your bike has been sitting for two weeks or more then you will probably want to put some air in them before you ride. Having your own pump makes this possible.
If all of this seems like far too much hassle for you, then you could look into getting a set of Tannus solid tyres. We reviewed them a few months ago and they have proven to be pretty good on London roads for lighter weight riders such as myself. They remove the need to worry about pumping your tyres, or getting a puncture on the way to work.
Some tyres hold their pressure better others. I have noticed that the more puncture resistant the tyre, the slower it loses air. I assume this is something to do with them being stiffer?
Avoiding large bumps, holes and curbs will keep your tyres happier for longer as well. Just today I witnessed someone speed up a curb and blow out two tyres (they were riding a trike). Even if the tyres don’t blow, repeated jarring will reduce their pressure quicker, meaning you might be at risk of flats sooner.
What are your tips and / or experiences with tyre pressures?