Bicycle Helmet Safety Institute

Results of USC Tests

Enclosed with this mailing are two articles detailing results of bicycle helmet tests conducted at the University of Southern California by Dr. Harry Hurt and David Thom. One is an article which appeared in an early issue of the new magazine Bicycle Rider. The other is a paper presented by Dr. Hurt at the American Association for Automotive Medicine conference (Stapp Conference) held in October.

We think that both papers represent major contributions to the field. In particular the accident performance analysis which begins on page 9 of the Stapp paper actually rates helmet performance in relation to impact severity in actual field cases, and states whether or not an ANSI helmet would have prevented an injury which occurred in a non-ANSI helmet. To our knowledge this is the first time such an analysis has ever been published.

While commending both articles to your attention we also had some reservations about the Bicycle Rider article which we had mentioned in the last issue of the Update. We reproduce those comments on the next page. Although they may sound critical, it is sufficient to note that we are doing this whole Update just to transmit these two articles, indicating that we think they are important to anyone who wants to understand bicycle helmets!

Helmet Article in Bicycle Rider

The Spring 1985 issue of the new magazine Bicycle Rider (published by TL Enterprises, 29901 Agoura Road, Agoura, CA 91301) carries an article titled "A Head of the Game". It was written by Joe Minton based on research done by Dr. Hugh Hurt and his research staff at the University of Southern California. Most of Dr. Hurt's recent work has been on motorcycle helmets, and his team is best known for "Motorcycle Accident Cause Factors and Identification of Countermeasures" (generally referred to as "The Hurt Study"), which includes a very thorough investigation of motorcycle helmet performance based on field studies of actual accidents. (Available through National Technical Information Service, Springfield, VA 22161 at about $35)

The Bicycle Rider article is a good one, and adds a welcome voice to the evidence presented to bicyclists supporting the use of good helmets. The author's approach differs from our own in several respects, so the article gives a new and interesting viewpoint. The differences are immediately apparent. Some of the language concerning the hazards of poor helmets is a lot more direct than WABA's cautious phraseology, which adds to the freshness of the approach. In the research for the article Dr. Hurt did not use either ANSI or Snell standard tests. His initial drop is close to the flat anvil part of the ANSI standard, but he did not perform the more difficult ANSI hemispheric anvil test. After that he departed from established standards entirely to use a new approach to drop heights and anvils. His staff averaged the head height observed in a number of bicyclists riding on a nearby path, and Dr. Hurt then used that height, 5'7". The anvil used was a chunk of pavement. Both decisions sacrificed standardized test results which would have facilitated comparisons, but readers may find it appealing to have the drop height equal to average head height, and use of a chunk of pavement certainly adds a harsh note of reality to the laboratory. There are no chin strap test results.

The article presents the actual observed numbers resulting from Hurt's tests, which immediately catch the reader's eye. There is an automatic tendency to rank the helmets according to these raw numbers, which must not be done in this case, since the good helmets were still a long way from bottoming out, and at the drop levels used any reading below 300 g's is exactly as good as any other reading below 300 g's. The careful reader will find this out two pages beyond the table, but must realize that without harder impacts, and without studying the oscilloscope traces accompanying the raw numbers which show the development of g forces over the split second following the impact of the helmet on the anvil the ranking of the helmets cannot be finished. We have already been told by one helmet importer that his helmet outperformed another one in the study "by 35%" because the raw numbers were 35% lower, despite the fact that both numbers were well below the 300 g threshold. We do not know if that statement reflects an excess of promotional zeal or simple ignorance, but it points up the reason we have not used raw numbers in our articles, and the reason why you must read all of Mr. Minton's article to understand the data presented.

(Note: We were too optimistic in those days about the adequacy of the 300g threshold. See our current page on The Ideal Helmet for more.)

Racers to Wear ANSI Helmets

The United States Cycling Federation (USCF) has approved a new rule which requires all cyclists in USCF sanctioned races to wear a helmet which meets or exceeds the ANSI Z90.4 standard. This rule takes effect on January 1, 1986. The racing community has long resisted this move, in part due to the competitive aspects of carrying another pound around the course and in part due to concern over the adequacy of ventilation provided by ANSI helmets for racing conditions. Racers are even now protesting. The USCF was motivated by concern over injuries and deaths in their races, and by the rising cost of liability insurance. Some USCF board members had been working for many months to promote the adoption of the new rule, but in the end it was probably the lawyers who swung the vote.

USCF has only about 17,000 members, but if the demonstration effect is worth anything this move may do as much for sale of helmets as Breaking Away did for the sale of sexy Italian racing jerseys. Keep an eye out for manufacturers who will hope to cash in on the new market--and the fashion which will imitate the racers--with lighter, cooler helmets. Let us hope that they do not sacrifice too much in the way of impact protection along the way. Kudos to USCF, and the people like Les Earnest and Ed Burke who have recognized the need for good helmets and the necessity of making them mandatory for all racers at the same time. We think local touring clubs will end up doing the same thing when their insurance premiums mount, and note that Bicycle USA has recently restated its own position in favor of hard shell helmet use. With the two helmet test standards now in place this may the be next frontier for promoting helmet use, but if clubs move too fast they risk a backlash which may result in fewer helmets on heads rather than more. We will pass along articles and such on this subject in the future.

Computer Bulletin Board

John Williams of Bicycle Forum has dedicated his personal Morrow to the Cause and now runs a bicycle activists bulletin board called Bikenet from his headquarters in Missoula, Montana. Although that means a long distance phone call from anywhere in the recognized world, John has some neat stuff on his board, including our Updates and the latest version of our helmet pamphlet. You can, for example, download the pamphlet, change all the graphics and stuff, and print it out the way you think it should be for local use in a pamphlet or newsletter. Please do not change the substance of the evaluations or add glowing comments on trash helmets, but otherwise feel free. John's RCPM is reachable on (406) , and is now up 24 hours a day, allowing you to take advantage of the cheap rates for later hours. John has had to start issuing passwords and such, and there is an annual subscription fee if you want to download.

Coming Soon

A revision of the "Consumer's Guide to Bicycle Helmets" pamphlet. John Spiegel's oft-promised study of children's helmets. A report from Tom Balderston, who is now in Nairobi working as a computer consultant to the Kenyan Ministry of Finance, on the value of pith helmets in head protection.


Randy Swart
Editor