Helmets come in all shapes and sizes. Before picking one, here's a surprising fact: the testing standards for helmets ensure that riders won't suffer permanent injuries when impacted at speeds of 20 km/h. The design is based on the maximum head weight (6 kg).
A helmet that reduces injury is like a car seatbelt—an example of “passive safety equipment.”
“What, only 20 km/h?”
If you love road cycling, you can probably easily exceed that speed. Not to mention pro cyclists who often reach nearly 100 km/h in high-tension races. It’s worth taking a moment to think: Is my helmet really safe? Bicycle Times invited Mr. Lü Dongfeng, Sales Manager of Proway Helmet Industry Co., Ltd. (hereafter referred to as Daniel), to explain:
Daniel said that in the early days of helmet development, there was one helmet for all purposes, called the “all-purpose helmet.” Later, models with visors were introduced. The latter, designed to block branches and rocks on forest trails, evolved into mountain bike helmets with the rise of mountain biking, reflecting riders’ rugged personalities through distinctive angles. Today, helmets are further divided into categories such as road, mountain, time trial, and casual.
A rounded shape with a large visor is characteristic of modern mountain bike helmets.
Traditional all-purpose helmets usually have an olive shape with a “ducktail” at the back, which improves aerodynamics and adds visual appeal. However, Daniel emphasized that the rounder the design, the smaller the deviation of impact force, and the more stable the head and helmet remain during rolling—helping avoid neck injuries from resistance. On the other hand, a cool pointed shape may actually increase friction if it hits the ground.
From the back, many road bike helmets feature a tail-down design.
Understanding the two types of helmet materials
Most bicycle helmets on the market are made of polystyrene. Daniel explains that this material is like aluminum alloy—lightweight and versatile. Once the glue inside sets, it achieves good protection. While polystyrene helmets are comparable to titanium alloy in processing limitations, they’re not as easy to manipulate in terms of weight and shape. However, they excel in shock absorption and strength. The foam itself is sticky, which is why they were initially known for their one-piece molding concept.
Beware, these areas are at risk
To achieve lightweight goals, polystyrene helmets use horizontal and vertical “ribs” for reinforcement, which intersect to enhance rigidity. But this material is particularly density-sensitive—the denser, the stronger. In other words, overly lightweight helmets aren’t necessarily safe.
“Is my helmet safe?”
To answer this question, Daniel suggests carefully examining whether the pre-expanded particles are tightly bonded. Daily exposure to organic solvents and UV rays can degrade the bonding in polystyrene helmets. Once cracks or damage appear, those become the weakest points under stress concentration.
Therefore, Daniel recommends avoiding leaving your helmet in the car for long periods to prevent exposure to airborne chemicals or solvents, ensuring safer usage. Of course, once a helmet has been impacted, it shouldn’t be used again—this advice applies to both material types.
Cracks appearing after prolonged use are signs of helmet aging.
After being hit on the side or back, the helmet shows noticeable cracks.
Remember, safety should be your top priority when choosing a helmet.
You might not know that currently, the safety inspection standards for bicycle helmets in China are the same regardless of the bike type. As cyclists demand more in terms of aerodynamics and ventilation, brands have been going all out with their designs, constantly altering the main structure of the helmets—so much so that even among top-tier professional riders, you’ll see a dazzling variety of styles on their heads.
Even among top-tier professional riders, the shapes of their helmets can be quite a blur.
"Compared to equipment, human factors are actually the biggest source of wind resistance," says Daniel. For everyday cyclists aside from professionals, the choice of helmet should prioritize safety. Keep in mind: wearing a helmet can reduce injury risk by 70%. In moments of danger, a good helmet is absolutely essential gear.
Finally, here are a few important points for cyclists to remember:
1. Avoid buying helmets from unknown sources—they might be substandard products that failed factory inspections.
2. The parts of the helmet that your hands frequently touch are more prone to structural weakness.
3. Avoid leaving your helmet in the trunk for long periods, as it will be exposed to prolonged UV rays and organic solvents.
4. When using a helmet, the “smallest size” that still feels comfortable is the one that fits you best.
5. Instead of focusing on brand names, choose a helmet that best matches the shape of your head—it’s what will protect you in critical moments.
6. The helmet strap should sit snugly under your chin, and the side buckles should be pulled up to ear level.
7. A lightweight helmet must still have good reinforcement—being light doesn’t necessarily mean it’s safer.
2014 Tour of Turkey, major crash in the peloton.