bicycle helmets not effective image
Rob G
The area they cover is only about 1-1/2% of your total frontal area. Motorcycles go much faster, and none of those are aerodynamically shaped. I've heard that you have to travel much faster than a bike is capable of, for the aerodynamics to be effective. For example a car has to travel in excess of 140mph for its' "wing" to have any effect. I know 1-1/2% is better than nothing, so why doesn't someone design some type of "body" air foil?
Answer
They have. They are called skinsuits, and all professional time trial riders use one. I think some have raised ridges sewed in, that delay air separation from the suit, thus reducing drag. Others use dimples in the fabric (same reason they put dimples in golf balls) that also delay air separation. In college, we had a lab that had a small wind tunnel and one of experiments was to test how much drag cold be reduced comparing a ping pong ball against the same ping pong ball modified with a small rubber band, and we found the band really did reduce drag even at slower air speeds.
They have. They are called skinsuits, and all professional time trial riders use one. I think some have raised ridges sewed in, that delay air separation from the suit, thus reducing drag. Others use dimples in the fabric (same reason they put dimples in golf balls) that also delay air separation. In college, we had a lab that had a small wind tunnel and one of experiments was to test how much drag cold be reduced comparing a ping pong ball against the same ping pong ball modified with a small rubber band, and we found the band really did reduce drag even at slower air speeds.
What is the California state law on riding bikes with helmets?
thename's
In California, is it required by law to wear a helmet while riding within neighborhood zones only?
where can I find an online source that has more information on this?
Answer
Hey Thename,
Anyone under the age of 18 years of age has to wear a helmet while riding any bicycle, scooter, skates or skateboard on any PUBLIC roadway, highway, bicycle path or street. The key word is Public. If your neighborhood is located on a private roadway then the law does not apply on private land. Here is the California Vehicle Code section:
21212. (a) A person under 18 years of age shall not operate a bicycle, a nonmotorized scooter, or a skateboard, nor shall they wear in-line or roller skates, nor ride upon a bicycle, a nonmotorized scooter, or a skateboard as a passenger, upon a street, bikeway, as defined in Section 890.4 of the Streets and Highways Code, or any other public bicycle path or trail unless that person is wearing a properly fitted and fastened bicycle helmet that meets the standards of either the American Society for Testing and Materials (ASTM) or the United States Consumer Product Safety Commission (CPSC), or standards subsequently established by those entities. This requirement also applies to a person who rides upon a bicycle while in a restraining seat that is attached to the bicycle or in a trailer towed by the bicycle.
(b) Any helmet sold or offered for sale for use by operators and passengers of bicycles, nonmotorized scooters, skateboards, or in-line or roller skates shall be conspicuously labeled in accordance with the standard described in subdivision (a) which shall constitute the manufacturer's certification that the helmet conforms to the applicable safety standards.
(c) No person shall sell, or offer for sale, for use by an operator or passenger of a bicycle, nonmotorized scooter, skateboard, or in-line or roller skates any safety helmet which is not of a type meeting requirements established by this section.
(d) Any charge under this subdivision shall be dismissed when the person charged alleges in court, under oath, that the charge against the person is the first charge against that person under this subdivision, unless it is otherwise established in court that the charge is not the first charge against the person.
(e) Except as provided in subdivision (d), a violation of this section is an infraction punishable by a fine of not more than twenty-five dollars ($25).
The parent or legal guardian having control or custody of an unemancipated minor whose conduct violates this section shall be jointly and severally liable with the minor for the amount of the fine imposed pursuant to this subdivision.
(f) Notwithstanding Section 1463 of the Penal Code or any other provision of law, the fines collected for a violation of this section shall be allocated as follows:
(1) Seventy-two and one-half percent of the amount collected shall be deposited in a special account of the county health department, to be used for bicycle, nonmotorized scooter, skateboard, and in-line and roller skate safety education and for assisting low-income families in obtaining approved bicycle helmets for children under the age of 18 years, either on a loan or purchase basis. The county may contract for the implementation of this program, which, to the extent practicable, shall be operated in conjunction with the child passenger restraint program pursuant to Section 27360.
(2) Two and one-half percent of the amount collected shall be deposited in the county treasury to be used by the county to administer the program described in paragraph (1).
(3) If the violation occurred within a city, 25 percent of the amount collected shall be transferred to and deposited in the treasury of that city. If the violation occurred in an unincorporated area, this 25 percent shall be deposited and used pursuant to paragraph (1).
Added Ch. 1000, Stats. 1993. Effective January 1, 1994.
Amended Sec. 6, Ch. 674, Stats. 1996. Effective January 1, 1997.
Amended Sec. 1, Ch. 475, Stats. 2002. Effective January 1, 2003.
Kimber
Hey Thename,
Anyone under the age of 18 years of age has to wear a helmet while riding any bicycle, scooter, skates or skateboard on any PUBLIC roadway, highway, bicycle path or street. The key word is Public. If your neighborhood is located on a private roadway then the law does not apply on private land. Here is the California Vehicle Code section:
21212. (a) A person under 18 years of age shall not operate a bicycle, a nonmotorized scooter, or a skateboard, nor shall they wear in-line or roller skates, nor ride upon a bicycle, a nonmotorized scooter, or a skateboard as a passenger, upon a street, bikeway, as defined in Section 890.4 of the Streets and Highways Code, or any other public bicycle path or trail unless that person is wearing a properly fitted and fastened bicycle helmet that meets the standards of either the American Society for Testing and Materials (ASTM) or the United States Consumer Product Safety Commission (CPSC), or standards subsequently established by those entities. This requirement also applies to a person who rides upon a bicycle while in a restraining seat that is attached to the bicycle or in a trailer towed by the bicycle.
(b) Any helmet sold or offered for sale for use by operators and passengers of bicycles, nonmotorized scooters, skateboards, or in-line or roller skates shall be conspicuously labeled in accordance with the standard described in subdivision (a) which shall constitute the manufacturer's certification that the helmet conforms to the applicable safety standards.
(c) No person shall sell, or offer for sale, for use by an operator or passenger of a bicycle, nonmotorized scooter, skateboard, or in-line or roller skates any safety helmet which is not of a type meeting requirements established by this section.
(d) Any charge under this subdivision shall be dismissed when the person charged alleges in court, under oath, that the charge against the person is the first charge against that person under this subdivision, unless it is otherwise established in court that the charge is not the first charge against the person.
(e) Except as provided in subdivision (d), a violation of this section is an infraction punishable by a fine of not more than twenty-five dollars ($25).
The parent or legal guardian having control or custody of an unemancipated minor whose conduct violates this section shall be jointly and severally liable with the minor for the amount of the fine imposed pursuant to this subdivision.
(f) Notwithstanding Section 1463 of the Penal Code or any other provision of law, the fines collected for a violation of this section shall be allocated as follows:
(1) Seventy-two and one-half percent of the amount collected shall be deposited in a special account of the county health department, to be used for bicycle, nonmotorized scooter, skateboard, and in-line and roller skate safety education and for assisting low-income families in obtaining approved bicycle helmets for children under the age of 18 years, either on a loan or purchase basis. The county may contract for the implementation of this program, which, to the extent practicable, shall be operated in conjunction with the child passenger restraint program pursuant to Section 27360.
(2) Two and one-half percent of the amount collected shall be deposited in the county treasury to be used by the county to administer the program described in paragraph (1).
(3) If the violation occurred within a city, 25 percent of the amount collected shall be transferred to and deposited in the treasury of that city. If the violation occurred in an unincorporated area, this 25 percent shall be deposited and used pursuant to paragraph (1).
Added Ch. 1000, Stats. 1993. Effective January 1, 1994.
Amended Sec. 6, Ch. 674, Stats. 1996. Effective January 1, 1997.
Amended Sec. 1, Ch. 475, Stats. 2002. Effective January 1, 2003.
Kimber
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Title Post: Why are bicycle helmets shaped the way they are?
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