Fact 1: head injuries account for approximately 80% of cycle related deaths

Fact 2: good quality helmets cost from £25

Hmmm... helmets, I don't like em all that much, but I'll wear one. Danger Rule number 512 states: 'always protect your brain and your wedding tackle'. When you are at speed it's very easy to wipeout onto rocks, tree stumps, and other solid things, so be prepared.

"I don't know about you but I'm not keen on the idea of having my head slammed into a muddy tree stump, so I splashed out £35 for a new helmet and if it makes me look like a dick, so be it."

Fit is vital when buying a helmet. Helmets come in a wide range of sizes and although they have internal adjustments some helmets will fit better on certain shaped heads than others. Opt for a good quality helmet, which fits your whole head snugly (i.e. that there are no obvious pressure points).

Ensure that when the main strap is fastened (under your jaw) that it is comfortable, doesn't dig in, and that the helmet fits low and square on your head (about a finger width above the eyebrow). Adjust the internal retention system so that the helmet is securely fastened. Grab hold of the helmet and try to rotate it, then shake your head from side to side and back and forth and ensure that the helmet stays in place on your head and that there is no slippage.

You can get a good quality helmet for about £25 so don't get a cheap one.

Helmet design
Function: Helmets are designed to protect the most vulnerable parts of your head (i.e. your forehead the back of your head) by absorbing the impact during a wipeout.
The internal retention system should not only stop the helmet from rattleing around on your head when riding on rough terrain but it should ensure the helmet remains in place during a crash.
	Materials and design: Lightweight molded materials enable manufactures to produce heavily vented designs (which keep your head cool) which are strong, comfortable, and aerodynamic.
Full face helmets are becoming the norm for downhillers and those into freeriding. They look a lot like a moto-x helmet complete with a solid chin guard but are of a lighter construction than a motorcycle helmet. They don't offer much in terms of venting, but they make up for it on the protection front.
Safety standards
Before you buy a helmet make sure that it has an appropriate saftey sticker in it. If in Europe it should have a 'CE' logo on the inside of the lid, and if you are in the US look for the 'CPSC' sticker or better yet the 'Snell' approval sticker. If you are thinking about doing some racing, don't remove the stickers because the scrutineers may want to see them.