Bicycle Helmets are strongly recommended, by doctors and by city and campus officials, for anyone who bicycles in Davis or anywhere else. They are also legally required in California for bicyclists under the age of 18. Head injuries are the biggest cause of death in fatal bike accidents and a major type of serious injury in non-fatal bike accidents (NHTSA Fact Sheet). Bicycle helmets prevent most head injuries and lessen many others. Doctors can repair many kinds of damage after a bicycle accident, but they cannot repair brain damage. Even a simple concussion is a type of brain injury; whether or not it leads to hospitalization, it may still involve insidious (meaning medically undetected) long-term brain damage.

Make sure that your bicycle helmet is in good condition. Throw the helmet away if it is damaged in an accident, or if it is weathered; replace it at least every five years. Sizing the helmet and adjusting the straps are tricky but important steps; the helmet and strap should be snug without feeling tight.

The helmet debate

Just as with motorcycle helmets and seat belts, there is some public debate as to whether it is important to wear a bicycle helmet. The scientific consensus, based on both case-control studies and ergonomic theory, is that bicycle helmets are important. Exactly how important they are and how to best design a helmet are a matter of continuing research (University of Washington Med school review).

Much of the debate is about bicycle helmet laws rather than about the merit of helmets. There is a libertarian argument that laws should not unduly protect people from themselves. This is one reason that bicycle helmets are not generally required for adults in the United States, and it is part of a continuing debate over motorcycle helmet laws. Few people would argue that children should not be protected from themselves, and that is why bicycle helmets are required for children in California.

It is true that bicycling is about three times as safe per mile of travel than walking in the US, as measured by fatalities (Pucher and Dijkstra, 2003). That makes bicycling less safe per hour, or per trip, because bicycling is about 5 times as fast as walking. Protecting pedestrians and bicyclists are both major public safety challenges that require many partial solutions. Even though helmets are not a good solution for pedestrians, they are an important solution for bicyclists.

It is also true that the rate of reported head injuries increased from 1991 to 2001 in the United States even though bicycle use fell in the same period (New York Times, July 29, 2001). A common time trend does not imply cause and effect and it is open to many possible explanations. For instance, doctors may diagnose a type of injury or illness more thoroughly or more liberally over time, so that a problem appears to get worse when it is actually only getting reported more.

The Wikipedia page on bicycle helmets is a better place to pursue the general debate over bicycle helmets and helmet laws than DavisWiki. The comments section of a DavisWiki page is a better place for debating than the main section, then gather them up and put them in the top as cogent points. Of course, since there are no rules — except that you *must* wear a Wiki helmet when debating on the wiki — feel free to ignore that.


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(undated) These testimonials have been moved to the comments section.

  • I was riding with a group of people traveling about 15-18mph on a county road. One guy hit a bump that caused him to lose his grip and fall forward onto his handlebars (he had been talking and pointing at something, leaving one hand on the grip). When the rear wheel hit the same bump, it bounced up and he landed head-first on the pavement. Two seconds. He ended up with a cracked cheekbone, broken nose, a concussion, and abrasions on his face. While we waited for the ambulance to arrive, I examined his helmet. The foam padding, where it rested on his forehead, was mashed flat. I shudder to think what might've happened had he not been wearing it. I don't know what the statistics say, but seeing that was enough to convince me that wearing a helmet is wise. (So is medical insurance...he didn't have any, unfortunately.) —DukeMcAdow
  • I have had but two encounters with cars in over 25 years of riding in Davis. In the latter, on 10/30/07, my helmet broke when it smashed into someone's windshield — probably saving me from a bad concussion and possibly saving my life! In the former, I was caught by someone's car door and left much of my forehead skin on G Street. (That might have been the last time I rode without a helmet!) Okay, neither accident happened on campus, but they have curbs, bollards & other noggin-mushing objects there too. Bicycle helmets are only for people who want to live with intelligence — if you don't mind a significantly higher chance of traumatic brain injury, don't worry your pretty little head about one. (That's an attempt at grim cynicism!) — DougWalter
  • Given that I've received a concussion from a solo bike crash while I was wearing a helmet, I fully support the wearing of helmets to mitigate head injuries. The idea of not wearing a helmet just seems absurdly stupid to me, especially if the reasoning is 'because it looks stupid' or 'because I feel stupid.' You could end up a lot more stupid if you crash while not wearing a helmet. —BrettHall

2007-10-26 15:01:16   Bicycle helmets are only for professors. They have so much invested in that noggin, it's actually worth protecting. Otherwise, bike helmets aren't cool. —BrentLaabs

  • Notwithstanding many professors are still wearing the same helmets they had 10 or 20 years ago, which have long since deteriorated to the point of uselessness. Which brings me to my next point: helmet standards were improved in 1999, and every helmet manufacturer recommends replacing a helmet every 3-4 years or after an impact, whichever comes first. The foam becomes brittle, so instead of crushing like it's designed to, it simply transmits the force directly into your skull. The paramedics will NOT thank you for using an old helmet if you crash. —BrettHall

2007-11-02 22:29:48   The amount of misinformation on this site regarding helmets is ridiculous. Several people here have suggested that helmets save lives when there is no evidence whatsoever that would support such an assertion. In fact, to the contrary, research has shown that as the rate of helmet use goes up, the rate of head injuries rises as well ( This is not at all surprising when you consider that helmets which meet current standard are only designed to prevent direct hits to the head at speeds of 12 miles per hour or less. Consequently, the most a helmet can do is to save you a few stitches or bruises if you fall off a bike; helmets offer practically no protection in serious accidents where one's life is at stake.

Furthermore, and perhaps most importantly, cycling is no more dangerous than walking( I am sure none of you wear helmets when you walk, why then would you wear one when riding a bike? —Maitl

  • 12mph is likely average or above average for most people riding on campus and in town (see also: everyone who is on department store or cruiser bikes). Which, by what Mait claims (which is indeed correct), is exactly the speeds for which helmets are designed. No, a helmet will not save you if you get hit by a car (very little will). But it can help immensely if you hit another cyclist, or if you cause yourself to fall and your head hits an object more solid than your skull. I'm as opposed to misinformation as you are, so you'll need a much better anti-helmet argument than "it won't save you if your life is on the line" won't fly with me - because helmets CAN and DO prevent serious injuries (see also: the concussion I suffered while wearing a helmet, in a crash where only I was involved - no, my life would not have been in danger without the helmet, but the helmet did save me a bloody head and trip to the hospital). —BrettHall
    • it can help immensely if you hit another cyclist, or if you cause yourself to fall and your head hits an object more solid than your skull: True, but the risk of becoming involved in such an accident and incurring a serious head injury is fantastically low. According to the US center for disease control and prevention, less than 1% of traumatic head injuries result from riding bikes. Given such an incredibly low risk, why should one wear a helmet, even if helmets are effective? Walking is just as dangerous as biking (if not more so), and helmets could undoubtedly also mitigate injuries resulting from walking, but would you wear a helmet each time you stroll through your neighborhood?
      • * The biggest difference between walking and biking is that when walking your feet are on the ground and your hands are probably free; while on a bike your hands are gripping the handlebars and the momentum of riding means that if the front wheel stops abruptly YOU will continue in an arc forward and down (being thrown over the handlebars and likely landing on your head). —LoisRichter
    • you'll need a much better anti-helmet argument than "it won't save you if your life is on the line": That was only part of my argument. Did you overlook the part where I said that the rate of head injuries has gone up as the rate of helmet use has increased? Did you click on the links I provided? The one leading to the bike helmet FAQ should have been particularly informative.
    • helmets CAN and DO prevent serious injuries: Helmets can also give their wearers a false sense of security which can increase the risk of injury. This is known as "risk compensation" and it may be one of the reasons why widespread helmet use has done nothing to lessen bike-related injuries. Another form of risk compensation may also occur as a result of wearing a helmet: according to a recent study, car drivers tend to drive less cautiously around helmet-wearing cyclists. (
      • * From that same article: "New York City released a report on bicycle deaths and injuries: 225 cyclists died between 1996 and 2005 on New York streets; 97 percent of them were not wearing helmets. Of these deaths, 58 percent are known to involve head injury, but the actual number could be as high as 80 percent." Davis isn't New York, of course, and our biking is seldom in direct competition with autos. But it still seems to me that wearing a helmet is safer than not. A helmet may not stop my crashing, but it may save me from head injury. —LoisRichter

  • If you watched the Tour de France, you'd realize how dangerous cycling can be. You said (without qualification) that cycling is no more dangerous than walking. Maybe that's true if you can walk 50 mph. Basically, you're saying that a head injury, when traveling at 5 mph, is no more dangerous than a head injury when traveling at 50 mph (or 20 mph, since that's a speed most of us can obtain when cycling). —KaiTing
    • If I was to watch the Tour de France, I would realize how dangerous bicycle RACING would be. The Tour is a race which is completely different from the short and relatively slow bike rides that the average cyclist undertakes. There is simply no comparison between my daily ride to class and Lance Armstrong's arduous, 3000 km trek through France; hence, the Tour de France says nothing about what the typical cyclist experiences. Furthermore, even if watching the event were a substitute for hard statistics and research, it still wouldn't help your case. According to the online encyclopedia Encarta, "accidents resulting in serious injuries or death are rare" and only three people have died in the tour's 100+ year history.—Maitl
    • Have you watched Nascar lately? Makes me scared to step inside a car!—JeffShaw

  • If wearing a helmet makes me at all safer in terms of the outcome of an accident then I will do it. By the way, your links refer to observational studies which can not be used to support the cause and effect relationships your arguments imply.—ScottMorgan

2009-08-02 12:17:21   I've noticed that the students around Davis (18 and younger, not the students at UCD) wear helmets that are solid, almost spherical, appear to be made of metal or a hard plastic, and have no ventilation. Everyone over 18 wears styrofoam helmets. Anyone know why the kids are wearing different helmets than the adults? Is there a law about this? Do they offer more protection? It doesn't seem like it would be much fun to wear a helmet with no ventilation in the Davis summer heat... —IDoNotExist

The solid-ish helmets are skateboarding helmets. They're fashionable for one reason or another, despite the fact that they suck. —wl

  • More often they are BMX helmets. Skateboarding helmets are designed for extremely low-impact, repeated collisions, and do not meet CPSC requirements for bicycle helmets (they spread the impact, rather than absorbing it). BMX helmets look similar to skateboarding helmets from the outside, but include the same crushable closed-cell foam found in 'regular' bike helmets. The law requires riders under the age of 18 to wear a CPSC-approved helmet. And yes, BMX helmets have little ventilation compared to other styles. —BrettHall

2009-08-02 14:11:30   So do they make regular, ventilated helmets in kids sizes too, or do the kids just have the BMX style helmets available? —IDoNotExist

  • Regular helmets are available in youth sizes. Baby helmets (meeting requirements for ages 1+) are giant bulbous things that aren't ventilated, but the kids wearing them are also not exerting themselves (and need more protection). So basically, when the kid's old enough to be riding a bike instead of being a passenger, there are ventilated helmets to keep the head cool and protected. Well, cooler, anyway. The BMX style is more popular among certain groups of youths, though. Answering why would require a graduate thesis. —BrettHall

2010-02-26 23:42:18   I once flipped over forward on my bike. My head bounced around three times on the pavement - I shudder to think what would've happened if I didn't have my helmet on me.

Best part besides being alive? My bike survived and still works to this day! Compared to my Target bike in freshman year, which crumpled as I was biking uphill one day. —AlexanderHo

2016-12-30 14:18:35   There are some other things (analyze as you want, please): * Promoting and providing helmets uses up the capacity of a city's politicians or departments; in the worst case, they take photos of themselves with kids holding helmets in the air, and do little else (fortunately, Davis is not like this, but then again there's a city-provided bus shelter on East Covell - with its oft-violated speed limit - that promotes helmets, which - as of last September - supported this plea utilizing a statistic that was discredited over three years ago; * The safest - at least Western - place to ride a bicycle is the Netherlands, where helmet wearing is marginal for non-sport use. This is because they prevent crashes via a strategy applied to the commons; rather than the still-common "American" strategy - or passive strategy, if you like - where at least perceived safety is a result of illumination which gets better if more money is spent, or pushes over-rated helmets, and requires them for children in many places (seriously a teen can drive alone at age 16 but has to be to ride their bike without a helmet! What kind of criminally-insane sustainable transport marketing campaign is this?! Was this law drafted by the automobile manufacturers and gasoline producers?); * True, a cyclist can fall with no involvement of a car. But in a good number of cases this is caused by potholes and similar caused by cars - it's a no-brainer to see why the UC Davis bikepaths have no such problems - so at best cars indirectly contribute to these crashing occurring. So, what's the deal? There are potholes in Davis which seem specifically-designed to catch bike wheels, and these include lateral deformations which seem to be a result of high summer heat, subsidence and perhaps the crowning of US local streets - it's more noticeable on narrower streets - a design which does not seem to be used in the places with high bicycle modal share in Europe (have to look into this last detail...). If there were lateral potholes in the street which were longer and wider than an automobile's wheel and a few inches deep and organized in parallel to catch both front wheels on a car there would be a riot; * It could be fun and interesting to compare the smoothless ratio of a shopping center parking lot to the surrounding streets/Greenbelt paths that lead to it (e.g. East Covell and its crossing with Pole Line TO the Nugget-CVS parking lot (Oak Tree Plaza). Happy Helmet-choice New Year! —DeepStreetsDavis