When choosing a bicycle helmet you mainly want to look at three things. Price, fit and keeping cool. Okay, and a forth thing, looking cool.1) Price
Starting with price. This can go up to around £150 and as low as £10. The truth helmet manufacturers don’t want you to know is you will receive most of the benefit with a cheaper helmet as you will with a more expensive one. At least when it comes to protection. However, spending more money should keep your head cooler and provide more comfort.2) Fitting a bicycle helmet
You will want to fit the helmet correctly because it will provide far better protection and it will feel more comfortable. A properly fitted bicycle helmet will reach about halfway down your forehead and will cover a good part of the back of your head. The more it covers the better.
The strap should fit closely under the chin and should form a v-shape around the ears. Not all bicycle helmets are born the same and some will fit better than others. After you have tried one and tightened it make sure it does not wobble.
The best bet is to go into a bike shop and try the helmet first. One will fit more comfortably than others. Ideally ask an assistant in the shop to fit the helmet for you. Alternatively, if buying online, make sure you measure your head correctly as instructed by the manufacturer.3) Keeping cool
In terms of keeping cool as you would expect more air vents equal more cooling of the head. However, more air vents also means that there is less of the padding to protect your head. You should pick a trade-off between the two.
As for weight? This doesn’t tend to be an issue as the majority of helmets weigh less than 300 grams.4) Looking cool?…
Lighter colours can be seen by other road users so go for brighter colours. You should aim to buy a helmet with a rounded outer shell so there is nowhere for the helmet to get caught in a fall.
Helmet advice via London Cyclist