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We hear lots of noise about ‘revolutionary’ new products in cycling. They are essentially never revolutionary, and frequently aren’t even new. But when Trek starts teasing a new product with the tag, “A change like this happens once every 30 years,” we’re pretty sure it’s a big deal. Speculation started. Was the lime green material teased a new frame material? Trek launched OCLV carbon about 30 years ago. But the biggest clue was that Bontrager touted the material as well, and it did look a bit like the Koroyd material used in Smith helmets. Now we know. Bontrager is incorporating a new material called WaveCel into its helmets which it claims is 48x more effective than EPS foam at preventing concussions during unplanned dismounts.
• WaveCel is a collapsible cellular material that reduces the effect of oblique head impacts that generate the rotational forces that can cause so much brain trauma.
• WaveCel is an alternative to the now ubiquitous MIPS layer used by Bontrager in many helmets and most other helmet manufacturers as well.
• According to a study at the Legacy Research Institute in Portland, Oregon, WaveCel is significantly more effective than MIPS in reducing both linear impact forces and rational forces on the brain.
• While similar in appearance to Koroyd used by Smith, Koroyd-equipped helmets still use a MIPS layer.
• WaveCel adds a little over 50 grams compared to non-WaveCel helmet’s weight.
As most people in cycling now know, it’s not the blunt impacts we should fear, it’s the oblique, angular impacts at high speed that cause so many concussion as well as life altering traumatic brain injury. Brain cells do not respond well to shearing forces. In the 10-15 milliseconds after an oblique impact it’s crucially important to spread that force out with 10-15mm of movement. If the helmet doesn’t provide that movement, your brain provides it by rotating in your skull. Yeah, that’s as bad as it sounds. Axons connecting brain cells go ‘snap.’
WaveCel provides that movement thanks to the design of its cellular material. Bontrager calls it ‘Flex, Crumple, Glide.’ In scientific circles this is called ‘rotational suspension’. The material has a flexible crease built in, then once that flex is used up, the material crumples on itself. Then, under rotational forces, it folds on itself and then finally it slides along the EPS foam exterior – ‘Flex, Crumple, Glide’. WaveCel works with ESP foam—it is not a replacement for it. It should also be noted that, like EPS foam, WaveCel only works once. After a crash, get a new helmet.
Bontrager worked with an orthopedic surgeon, Dr. Steve Madey, and a biomechanics engineer, Dr. Michael Bottlang, for four years to create and integrate this new material with its helmets. Today Bontrager has launched four new helmets with WaveCel. The XXX WaveCel Road helmet is the top end road lid and will be used by the Trek-Segafredo pro team. It retails for $300. For $150, WaveCel can be had in the Specter road helmet, and WaveCel commuting and MTB helmets are also available: the Charge and Blaze for $150 and $300 respectively.
WaveCel adds an average of 53 grams across all sizes to the helmet. That puts a small XXX WavCel Road at 325 grams—certainly not the lightest helmet, but on par with many MIPS equipped helmets from other manufacturers. For comparison, a MIPS equipped Bontrager Velocis helmet is 279 grams. The weight-for-safety trade-off does not concern us. The XXX WaveCel has the look of an aero road helmet, although no aero numbers were provided. It has seven large vents up front and three exhaust vents in back, although how well the exhaust vents draw across the head with the WaveCel material in the way is yet to be determined—which is what has us a bit worried: high speed venting. The cellular structure of WaveCel is vertical in relation to your head, and we imagine at high speed it will reduce flow and cooling. No ventilation comparisons were provided by Bontrager. Perhaps in the heat of the tour, Trek riders will opt for the Velocis or event the Specter, which is a bit lighter and has more-traditional venting. We look forward to a full summer road test to find out. The XXX feature BOPA adjustment, AgION antimicrobial pads with a silicon strip to channel sweat away from your eyes as well as free replacement in year one if you have a crash. The XXX WaveCel is a handsome helmet, although we like the more subdued smoke color for the WaveCel than the hi-vis lime green.
Bontrager provides some pretty startling force reduction numbers. Its WaveCel helmets can prevent concussions 99% of the time from common cycling accidents and is 48x more effective than a traditional EPS helmet. But we don’t need to take Bontrager’s word for it. It has a peer reviewed study from the Biomechanics Laboratory at the Legacy Research Institute in Portland, Oregon as well as top five-star marks for all its WaveCel helmets from the Virginia Tech’s helmet test lab. We’ll dig into the testing below, but if you want it from the horse’s mouth, you can get to them directly with the links below. It is important note that WaveCel inventors, Dr. Steve Madey and Dr. Michael Bottlang, are authors of the study, as well as founders and co-directors of the Legacy Research Institute.
Interestingly, for the study performed at the Legacy Research Institute, no Bontrager helmets were used. Instead the SCOTT ARX was used in three forms – the traditional ESP ARX as control, the MIPS equipped ARX Plus and then an ARX adapted for WaveCel. 15mm of EPS foam was robotically milled out of a traditional ARX helmet and then replaced with WaveCel to simulate the helmet’s original thickness.
Twenty each of these helmets were tested using a Hybrid IIII test head and neck assembly fitted with accelerometers. Five helmets of each specification were used for each impact and then the results were averaged. From a vertical rig, the helmets fitted to head and neck form were dropped onto an anvil in the following scenarios: drops at 4.8 meters per second onto 30, 45 and 60 degree anvils, then at 6.2 m/s onto a 45 degree anvil. For reference, 4.8m/s is almost 11mph and 6.2m/s is almost 14mph. Each drop used a brand new helmet.
WaveCel performed exceptionally well in this study. In reduction of straight-up linear impacts, the thin MIPS layer unsurprisingly does not reduce that force at all compared to a traditional EPS helmet. The WaveCel performed very well, reducing the force of linear impacts on the head by 16 percent on the 60 degree impact and 26 percent on the 30 degree anvil. At 6.8 m/s, all three helmets provided essentially the same reduction.
But MIPS is not about linear impacts, it’s all about reducing rotational force. How do MIPS and WaveCel compare there? Rotational forces are measured in two ways: rotational acceleration and the ultimate velocity of the rotation. The MIPS equipped ARX helmet was very good at reducing these forces. Compared to the non-MIPS equipped ARX, at slow speeds rotational acceleration is reduced by between 21 and 44 percent at 30 and 45 degree impacts respectively by MIPS. At 6.8 m/s, the reductions were less dramatic for the MIPS helmet. The WaveCel-equipped helmet performed even better. At the low end, a 34 percent reduction at 60 degree impacts at 4.8 m/s and up to a whopping 73 percent reduction at 45 degrees at 6.2 m/s.
How about rotational velocity? Again, MIPS performs well, but not as well as WaveCel. Compared to the control ARX helmet, MIPS reduced overall rotational velocity by 15 percent during 30 degree impacts at 4.8 m/s and 67 percent during impacts of the 60 degree anvil at 4.8 m/s. WaveCel saw reductions in ultimate rotational velocity by 50 percent during a 30 degree impact at 4.8 m/s. And that number jumps all the way up to an 84 percent reduction at the high speed 6.8 m/s impacts of the 45 degree anvil.
What do these reductions in forces mean as far as reducing actual brain injury? A lot, actually. Metrics have been created to predict brain injury and the results are amazing. It’s called the BrIC—Brain Injury Criterion—and using peak rotation velocity as recorded by the head form’s accelerometers, the chances of sustaining an AIS 2 level brain injury —that’s a mild to severe concussion with potential loss of consciousness—can be calculated. Compared to the control helmet, the MIPS ARX was very good, reducing chances of an AIS 2 brain injury by 32 percent during slow speed impact at 30 degrees and up to 91 percent during slow speed impacts at 60 degrees. As good as this is, WaveCel was better, reducing the chance of AIS 2 injury over the control helmet by 81 percent during slow impacts at 30 degrees and by a staggering 98 percent at 45 degrees during fast impacts. When looking at the ‘injury probability’ bar graph included in the study, the WaveCel equipped helmet is basically a tiny sliver at the bottom of the chart—almost undetectable. That’s the kind of injury probability we want: undetectable.
While this new material may not be as sexy as an über-stiff, lightweight new frame material, from a safety perspective—assuming the data is good—WaveCel is certainly new and indeed revolutionary. We may all feel superior to football fans as we go for a long ride on Super Bowl Sunday and feature lower BMI’s, but when it comes to concussions, we’re in the same boat as those football players. It’s a problem the sport needs to take more seriously and WaveCel from Bontrager looks like a great place to start.
Look for a ride test in the pages of PELOTON soon and for more info now head to trekbikes.com/wavecel.