How to choose a bicycle helmet: size, fit, and Mips

First, choose the purpose

For road and long gravel rides, an open helmet with convenient ventilation is often considered. For more technical MTB, there are models with increased coverage, and for downhill, there are corresponding full-face options. The purpose of a specific model is more important than its external similarity to another helmet.

Giro divides the choice by riding conditions. To participate in the race, also read the regulations: sports requirements for helmet type may vary. Do not buy a specialized model just for the look.

The scenario of trips can be clarified in overview of disciplines. A child needs a suitable size and adjustment method; an adult helmet with extra room doesn't become a child's helmet.

How to measure your head and read the size

Wrap a soft measuring tape around your head in the widest area, as shown in the manufacturer's instructions: usually above the eyebrows and ears. The tape should lie flat. Write down the circumference in centimeters and check the range of the specific model.

In Giro table Different lines have their own ranges and shapes. The letter M does not have to be the same for all manufacturers. If the measurement falls within the overlap of two sizes, try both.

Training example: a 57 cm circumference can fall into two size ranges. It does not allow you to select one by letter. The next step is to check the fit of these models on the head.

What to check during fitting

1. Put on the helmet according to the instructions, without tilting it back. The forehead must be covered in the provided way, and the view must be unobstructed.
2. Adjust the occipital system and straps. Do not try to correct an ill-fitting shape by overtightening.
3. Check that the helmet remains stable during head movements and does not slide during the retention check described by the manufacturer.
4. Leave it for a few minutes: local pain and strong pressure are reasons to try a different shape or size.
5. Check compatibility with the glasses and clothing you actually use without violating the mounting instructions.

Fitting recommendations have been checked against the Giro chart and manual. If the helmet slides easily with the straps fastened, do not consider the presence of a rear wheel as sufficient adjustment.

What markings to look for

Check the name of the manufacturer and model, size, designation of the applicable standard, and instructions. EN 1078 and CPSC are found in European and American offerings; they are not the name of the same test. There may be additional requirements for specific disciplines.

CPSC recommends checking the markings inside the bicycle helmet. The inscription 'professional' in the store and the familiar shape of the case do not replace information about a specific model.

Before the start, match the model with the organizer's requirements. Race documents are sorted in separate instruction; there is no universal admission for all events.

What is Mips

Mips is a system designed to reduce the transmission of rotational motion at certain oblique impacts. Its design may vary for different models. Giro describes the principle of a low-friction layer and separate implementations of the technology.

The presence of a system does not guarantee protection against any fall and does not replace a proper fit. First, exclude models that don't suit you, then compare technologies and available tests of specific helmets.

Do not evaluate a helmet only by the yellow label or price. With the same budget, consider the purpose, confirmed model, fit and the ability to use it normally in your conditions.

When to replace and whether to buy used

After hitting the helmet, damage to the absorbing layer may occur, which is not visible from the outside. Giro recommends replacement after accident; check additional replacement conditions and usage period in your model's manual.

For a used helmet, the history of impacts is sometimes impossible to establish. An external inspection and the words 'no scratches' do not confirm it. When buying, check the origin, set of straps, absence of changes, and return conditions; for protective equipment, an uncertain history is a significant disadvantage.

Also take storage and cleaning rules from the instructions: solvents, heat, and DIY case modifications can damage the product. Sources checked on October 9, 2026; fitting and comparative impact test of models for the article were not conducted.