Cheap or Expensive Bicycle Helmets
Summary: We submitted samples of six helmet models to a leading U.S. test lab: three in the $150+ range and three under $20. The impact test results were virtually identical. There were very few differences in performance among the helmets. Our conclusion: when you pay more for a helmet you may get an easier fit, more vents and snazzier graphics. But the basic impact protection of the cheap helmets we tested equaled the expensive ones. Just look for a helmet that fits you well.
We are often asked if cheap helmets protect well. Bike shop sales people like to warn customers "buy a $10 helmet for a $10 head." A well-known, reputable US test lab agreed to test some very cheap and very expensive helmets for us to compare their performance in ASTM/CPSC testing at both regular drops and lower impacts. They also did testing with a bio-fidelic headform. To our surprise, the results were virtually identical for all the helmets.
Our cheap helmets came from Target and Wal-Mart. They cost $9.96, $9.99 and $19.96 and were typical of helmets you would find in any big box discount store. Our expensive helmets came from a bike store, an Ebay seller and an Internet retailer. Two were made in China for US brands. One was Italian. The MSRP for them was $149.99, $174.99 and $206.99. We found the first two discounted, but paid full price for the most expensive one. We submitted three of each model for testing.
The test lab donated their testing, and we agreed not to use their name or the exact helmet models to avoid possible complications that could be time-consuming for them.
The lab performed normal CPSC testing on each model. We limited the anvils to flat and hemispheric, eliminating the curbstone anvil, and they tested at ambient temperatures, eliminating the high temperature, low temperature and wet tests. That still represents a very high percentage of real-world impacts.
The lab crashed the helmets with a two meter drop on the flat anvil and a 1.2 meter drop on the hemispheric anvil (grapefruit sized ball). These are normal CPSC impacts. They also ran lower level impacts at half of the CSPC velocity, using drop heights of only .5 meters on the flat anvil and hemispheric anvil impacts at .3 meters to test lower level performance. We were looking to see if the harder foam in more expensive helmets might fail to crush enough in less-than-catastropic impacts, possibly contributing to concussion risk. In fact, that did not happen.
The surprise for us was that all six helmets performed virtually identically in all the tests. There were a few outlying readings below and above the norm in particular spots, but the averages for the two types of helmet were almost identical. Below is a summary of the g levels, condensing many charts and numbers.
Average Test results in g's
|Average for all impacts||101||104
Low velocity tests
|Average low velocity||65||69
| Average low flats||86||87
| Average low hemi||47||47
High velocity tests
|Average high velocity||137||146
| Average high flats||186||180
| Average high hemi||91||113
The numbers showed that the performance of the two categories was almost identical. In lab test terms there is no real difference in those g levels. The high velocity hemispheric anvil tests favored the cheaper helmets somewhat, but represent only a small percentage of real world impacts. Both we and the test lab examined pages of test records looking for distinguishing patterns. We finally concluded that all of the helmets in our sample were designed to meet the same CPSC impact standard, and there is little to distinguish their impact performance, regardless of price.
The lab also recorded the coefficient of restitution of each helmet, representing how much the headform bounced after the impact, and the time interval in milliseconds that the g level exceeded 200g and 150g, a measure known as "dwell time" that supplements peak g readings. Both measures again yielded no significant performance differences. Finally, they tested each model on a different headform, a bio-fidelic NOCSAE headform that attempts to more closely replicate a human head than the magnesium CPSC headforms do. Again the numbers were close enough to be functionally identical.
The cheaper helmets in this testing did not outperform the more expensive ones, despite their smaller vents that usually mean more foam. Although there are probably at least some helmets out there with more or less than this uniform level of protection, we did not find any in this test. Neither the lab nor BHSI could find significant differences that would lead to individual brand recommendations. That is remarkable considering the $10 to $200+ range of prices.
The results are a testimony to the effectiveness of our legally-required CPSC helmet standard. Although our sample was small, the testing indicates that the consumer can shop for a bicycle helmet in the US market without undue concern about the impact performance of the various models on sale, whatever the price level. The most important advice is to find a helmet that fits you well so that it will be positioned correctly when you hit.