Anthony Marchand Bicycle Repair And Maintenance information And Tips
Do all bicycle helmets meet US standards? Yes
All bicycle helmets sold in the US are certified by the US Consumer Product Safety Commission according to a standard procedure.
How are they tested?
The procedure involves filling the helmet with a cloth filled bag of lead shot and dropping it from a standard height onto an anvil. The helmet is marked so the impact is just forward to the top center. An instrument called an accelerometer measures g force in the center of the head form. If the helmet works well, the g's are low. If the g's exceed 300, the helmet fails.1 We call this type of testing "linear or direct impact."2 Consumer Report also tests linear impact to a variety of points on the helmet.3
What should I buy?
The top 5 helmet showing the overall best results for direct rotational impact included Bell Stoker MIPS, Giro Savant MIPS, POC Octal AVIP MIPS and Spectra Urbana MIPS, which are all fitted with MIPS (Multi-directional Impact Protection System) as well as the Hovding 2.0.4 In oblique impact tests helmets equipped with MIPS (which protect against rotational impact) performed better than helmets without the system. But not all MIPS helmets meet the standard. Two helmets, Giro Sutton MIPS and Scott Stego MIPS, showed lower protection than the average good helmet even though these were equipped with rotational protection.
The greatest difference between a good and a bad helmet is how well it protects the head during oblique impacts. In addition, the limits for linear (direct) impact need to be lowered. Until the US Consumer Product Safety Commission incorporates lower linear impact and rotational impact (MIPS) into their standards, we will have to rely on studies such as that of the Folksam Group of Sweden (Note: Consumer Report, as of this date, did NOT measure rotational protection7).
How the helmet is strapped to the head is also of primary safety importance!!!
Is Your Helmet Safe: How valuable is your brain?
Anthony Marchand bicycle repair and maintenance information and tips.
Doesn't this mean they're all safe: No
According to a recent 2015 study by the non-profit group Folksam4 from Sweden, a direct impact of 250 g will result in a 40% chance of skull fracture. Therefore, some helmets meeting U.S. limits can results in up to 60% chance of fracture (or more).
Can bicycle helmets be made safer: Yes
Of the 18 helmets studied by Folksam, all but 5 showed a linear acceleration below 180 grams which means only a 4% chance of skull fracture. However, of the 5 that failed included some popular brands such as the Giro Sutton MIPS. The Hövding 2.0 helmet performed almost three times better than all the other conventional helmets (48 g vs. other helmets that were around 175 g). So it is clear that all bicycle helmets are NOT the same and helmets can be made significantly safer than the U.S. standard.
What is MIPS:
Multi-directional Impact Protection System - MIPS - is a concept involving the slip plane, using two layers in the helmet to help the head rotate slightly on impact. The outer shell is separated by 7 mm from an inner shell. This separation allows the inner shell to rotate within the outer shell damping the " rotational impact" of any crash as opposed to "linear or direct impact." Rotational impact is felt to be the primary source of brain injury mechanism and related to concussion.5, 6 Most bicycle accidents involve rotational impact!
What is the Hovding 2.0 helmet?
The Hovding 2.0 helmet involves an inflatable cuff placed around the neck. A build in sensor detects abnormal movement as might occur in a bicycle crash. In such cases the "air bag" inflates in milliseconds to protect the rider from head injury.
The g force delivered to the skull is reduced to 48 g vs. other helmets that are around 175 g and above. A far cry better. One must note that there is no protection from impact such as may occur if striking a low tree limb and the helmet must be replaced once inflation occurs. As pointed out in the video, the cost of replacement is far less than an emergency room visit. The vast improvement in protection makes one wonder if this is the wave of the future.