Giant Rivet TT Road Cycling Helmet 2017

Core

Bike helmets are constructed of Expanded Polystyrene (EPS) which is a great material for absorbing impacts, whilst being lightweight. 

Nowadays almost all helmets use in-mould technology where the shell and EPS core are moulded together, allowing for more intricate shaping for vents and aero designs. It also stops the shell separating from the core. Crucially in-mould lids improve impact forces transferring to the foam core.

Consider foam density when making your choice. Helmets with single density foam will deform more in a collision than those with multi-density foam, which offer more impact protection.

A brand-new material called Koroyd is coming onto the market and offers enhanced protection with a lighter weight. Thermally welded hollow tubes form a honeycomb structure which can absorb 30% more energy than a similar cycling helmet made from polystyrene. Koroyd also enhances ventilation as all those hollow tubes allow heat to escape.

Fit & Straps

Fit is a key part of safety and comfort. All road helmets feature an adjustable fit system that ensures the helmet stays securely attached to your head.

There are a few variations, but the theme is generally the same, a retention system pulls the inside liner webbing together to cradle your head. Many helmets will come with a ratchet dial on the rear that you can adjust. Look for a dial system that can be used easily with one hand, so you don’t have to stop cycling to adjust the fit. Premium lids will also come with height adjustment, offering a better fit for all head shapes.

Chin straps are there to keep your helmet in place, even if you have a fall. These are usually fully adjustable on all helmets.

Ventilation

When choosing a road cycling helmet, ventilation is key for comfort and it will be a big factor in the cost of the lid you choose. The general rule of thumb is the more expensive a road helmet is, the more advanced the ventilation will be, and the more vents you’ll get.

More sophisticated venting systems link deep vent channels from the front through to the rear of the helmet. These channels work to pull cooling air over your head and out through the exhaust ports.

Aero road helmets will limit the use of vents to create a clean, slippery profile to help reduce drag. You can even find helmets with vents you can snap shut if you need an aero boost, or open for breathability. You’ll find that TT lids will have no vents at all because of aerodynamics.

It is important to get a helmet that fits correctly. Simply measure the circumference of your head and match it to the helmet size. Do this by placing a tape measure on the centre of your forehead and wrap it around your head above the ears. See our clothing size guide for more details.