MTB helmet test: 15 MIPS helmets for trail and enduro in the lab and in practice

Buy cheap, buy twice. As much truth as there is in this saying, even the first mistake with a bicycle helmet can have fatal consequences. If the helmet does not fulfil its intended function, slips off your head in a fall or even breaks. But is it actually true that cheap helmets are less protective than expensive ones?

In our current test, this question is a real question, as Decathlon is launching an MTB helmet with a MIPS system for the first time with its own brand Rockrider. Cost: 59.99 euros. The next most expensive model in the test costs 40 euros more. Instead of the two high-end helmets from Poc and Smith, you could buy nine (9!) Rockrider EXPL 540s. Where does the price difference of up to 210 euros come from?

These MTB helmets with MIPS are in our test

• Abus Cliffhanger Mips >> available here
• Alpina Taunus Mips >> available here
• Bell 4Forty Air >> available here
• Bluegrass Rogue Core Mips >> available here
• Cratoni Madflex Mips Recco >> available here
• Decathlon Rockrider EXPL 540 Mips >> available here
• Fizik Kassis
• Fox Speedframe RS >> available here
• Giro Source Mips >> available here
• Met Revo >> available here
• Poc Kortal Race Mips >> available here
• Scott Tago Plus >> available here
• Smith Forefront 3 >> available here
• Troy Lee Designs A3 Mips >> available here
• Uvex Renegade Mips >> available here

Equipment of the bicycle helmets

Every additional feature costs money, that much is clear. An adjustable headrest, adjustable Y-belts (which improve the fit below the ears) or a height-adjustable visor - and that's just the basics. Many manufacturers provide magnetic belt buckles from Fidlock, which are really practical, or twist locks from Boa, which we didn't like so much. Goggle holders, goggle garages, camera mounts or a transport bag round off the equipment.

Decathlon, by far the cheapest supplier, uses a simple adjustment system without height adjustment at the neck and ears, the visor is fixed and the padding is simple. But as long as the helmet fits the head, the Rockrider also fits properly. The only real criticism: the headband is not circumferential, which makes the fit a little worse.

Very different wearing comfort

Its big plus, however: The Rockrider EXPL 540 is light. It weighs just 330 grams, almost a third less than the Cratoni. Especially on long tours, you can really feel the heavy weight of a Madflex on the back of your neck. Otherwise, only the models from Scott, Giro, Abus or Alpina reach a similar weight range to the Rockrider - although they are already much more extensively equipped than the Rockrider.

The EXPL 540 cannot keep up with the best models in the test in terms of ventilation either. A look at the inside explains why: you won't find any elaborate ventilation ducts or large air intakes here. The helmet shell sits close to the head, which prevents the wind from flowing through. In contrast, the Abus, Bluegrass and Uvex helmets are almost wind force 6, but in defence of the Rockrider, it has to be said: Even expensive models such as the Fox Speedframe RS or the Smith Forefront 3 do no better here.

How to: Even the best helmet cannot provide optimum protection if it is incorrectly adjusted. We show you how to determine the right size of bike helmet and how to adjust your MTB helmet correctly.

MIPS can be found on almost all helmets

Incidentally, this is our first test in which no manufacturer wants to do without a MIPS system - or manufacturers who install their own rotation systems didn't want to take part in the test. The fact that rotational movements, as they affect the head during a fall on a bike, can be extremely damaging to the human brain, seems to have reached the minds of the manufacturers. Decathlon relies on the standard version of the rotation protection, whose bright yellow liner should be familiar to every biker by now. The differences between the individual systems, some of which are elaborately integrated into the helmets, are explained below.

What can the cheapest test helmet do?

But much more exciting is the question: How does the Decathlon helmet perform in terms of safety? There are two surprises here: With a residual force of 107.9 g, the Rockrider is pretty much in the middle of our test field and a whole 142.1 g below the permissible limit. What surprised us even more, however, was that Decathlon achieved the best value for rotation protection with the standard MIPS, which is impressive: If you don't have any great demands when it comes to equipment, you can also ride through the terrain well protected with an inexpensive helmet like the Rockrider EXPL 540.

The test clearly shows that expensive helmets do not necessarily provide better protection. The best example is the model from the discounter Decathlon, which costs just under 60 euros. Because all helmets easily fulfil the standard, a clever adjustment system is at the top of my checklist. Scott, Alpina, Bell and Giro are easy to adjust and don't tear too big a hole in the budget. More than 400 grams is too much for a trail helmet. - Stefan Frey, BIKE editor

The most important findings from the MTB helmet test

How BIKE tests the MTB helmets

Security (50 per cent)

Special safety technologies - MIPS & Co. - are designed to measurably reduce the risk of head injuries by reducing the rotational forces that occur in the event of an oblique impact. The existing test standard for helmets, EN 1078, cannot cover these scenarios. In order to test the current generation of helmets realistically, we have developed a helmet test rig ourselves, using the methods used in science and by research-based manufacturers.

For the test, the helmet is fitted to an aluminium test head weighing 4.9 kilograms. During the simulated fall, the helmet and head are guided on a sled and hit a steel surface inclined at an angle of 45 degrees at a speed of 21 kilometres per hour. Sandpaper with a grain size of 40 imitates the roughness of the surface - this is similar to the test facilities at Virginia Tech, Folksam and other research institutes. The sled whizzes past the contact surface and releases the helmet, which bounces away after the impact.

Measurement with six-axis sensor

A six-axis sensor in the test head records acceleration and rotation rates around the three axes in space on impact and in the subsequent flight phase. In the first run-up, the helmet hits frontally, in the second laterally. We analyse the acceleration according to the highest resulting value - the lower the better. The average value from four measurements is given. We convert the head rotation into the BrIC criterion (Brain Injury Criterion), which indicates how damaging the movement is to the brain. This method is widely used in science and enables statements to be made about the probability of a concussion using the so-called AIS code.

Weight (15 per cent)

The head reacts particularly sensitively to additional weight. 50 grams more or less makes a big difference here. Our test shows that more weight does not automatically mean better protection.

Adjustment (20 per cent)

In terms of customisation, we assess the design and adjustability of the head ring as well as the course, fit and fastening of the harness system.

Cooling (15 per cent)

We test the ventilation of the helmets with a powerful fan that accelerates the airflow up to 30 km/h. The heated, helmeted head is exposed to the flow and we determine the cooling capacity.

Our top 3 helmets from the test

• The best in the lab The Bluegrass Rogue Core offers the best compromise between impact and rotational protection and is also very well ventilated. Only the inexpensive Rockrider with the simple MIPS layer reduces rotational forces even better.

• The best customisation Easy-grip swivel wheel, simple height adjustment, all-round headband and adjustable Y-belts the Scott Tago can be perfectly adjusted to the head. A magnetic lock from Fidlock would have been the icing on the cake.

• The surprise Apart from the simple furnishings, there are Rockrider EXPL 540 has little to criticise: Best rotation protection, good shock absorption and low weight at an unrivalled price.

The measured values from the laboratory at a glance

Although all helmets in the test fulfil the EN 1078 test standard, a 50 g higher impact force can make a big difference in the event of a fall.

The table shows the probability of a biker suffering an average concussion in the fall scenario we simulated. This can be calculated from the measured rotational movements (BrIC, Brain Injury Criterion). The relationship between BrIC and the probability of a concussion (according to the AIS code) is not linear. The probability is therefore more suitable for the assessment. The risk of concussion is between 12 and 31 per cent and averages 22 per cent. The risk of suffering a concussion with a helmet without MIPS was 37 per cent on average in earlier tests.

All helmets in the test remain well below the standard (250 g) in terms of acceleration values, i.e. the forces that still act on the head in the event of an impact. However, the range extends from 79.3 g (Bluegrass) to 134 g (Giro) and shows that the helmets provide different levels of protection. We were unable to establish a correlation between reduced rotational acceleration and good shock absorption in previous tests.

How the various MIPS systems work

Scientific studies have shown that the human brain reacts particularly sensitively to rotational forces. The low-friction MIPS shell (Multi-directional Impact Protection System) was designed to reduce rotational energy in the event of an angled impact. It is designed to allow the helmet to slide offset to the head. This converts rotational energy into translational energy. This mechanism is similar to the behaviour of the head in a fall on ice, where the head can continue in the original direction of movement. Various versions of the MIPS system are currently available that allow a relative rotation between helmet and head in the range of 10 to 15 millimetres. Our tests show that the probability of suffering a concussion with a MIPS-equipped helmet (according to the AIS code) was 22 per cent on average. In comparison, the average probability of concussion for helmets without MIPS was a significantly higher 37 per cent in an earlier test.

Mips Essential Core

Essential or the classic MIPS with a yellow shell, the so-called LFL (Low Friction Layer), is often used in low-cost helmets. It is held in the helmet by elastomers. In the test, we measured BrIC values (Brain Injury Criterion) of 12 to 20 per cent.

Mips Evolve Core

Like the Essential, the system sits between the helmet shell and padding. A fit that is tailored more precisely to the respective helmet is intended to improve ventilation and reduce weight. It is now the most frequently installed MIPS.

Mips Air Node

Here, the rotation protection is integrated almost invisibly into the helmet padding. This saves weight and does not impair ventilation with an additional layer. The sliding layer is located on the inside of the padding.

Mips Integra Split

Fox relies on a particularly elaborate construction. The helmet consists of two separate shells that can be twisted against each other. The construction is somewhat heavier and more expensive, but only achieved moderate values in the laboratory.

Mips Integra Fuse

Poc and MIPS have combined their two rotation systems to create Integra Fuse. Here, the padding contains a type of silicone that can move in all directions. Similar to MIPS Air, the advantages are said to be low weight and good ventilation. In any case, the rotation protection is very good.

MIPS is still the subject of controversial debate. However, the range measured in the test is considerable in any case. For me, the effectiveness seems plausible. - Prof. Dr Stefan Lorenzl, specialist in neurology