1、Designation: F 1952 00An American National StandardStandard Specification forHelmets Used for Downhill Mountain Bicycle Racing1This standard is issued under the fixed designation F 1952; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revisi
2、on, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers performance requirements forhelmets used by downhill mountain bicycle rider
3、s. Studieshave shown higher risk to the head and face for this sport ascompared to recreational street riding; hence, this specificationrequires greater impact protection and provides performancecriteria for chin bars on full-face helmets, but does not requirefull-face helmets. This specification re
4、cognizes the desirabilityof lightweight construction and ventilation; however, it is aperformance specification and is not intended to restrict design.1.2 All testing and requirements of this specification shallbe in accordance with Test Methods F 1466, except wherenoted herein.1.3 Partial utilizati
5、on of this standard is prohibited. Anystatement of compliance with this specification must be acertification that the product meets all of the requirements ofthis specification in its entirety. A product that fails to meet anyone of the requirements of this specification is considered tohave failed
6、this standard, and should not be sold with anyindication that it meets parts of this standard.2. Referenced Documents2.1 ASTM Standards:2F 1446 Test Methods for Equipment and Procedures Usedin Evaluating the Performance Characteristics of ProtectiveHeadgear2.2 Other Standards:1995 Standard For Prote
7、ctive Headgear For Use with Mo-torcycles and Other Automotive VehiclesSection C4. Chin Bar Test33. Labels and Warnings3.1 Shall meet the requirements of Test Methods F 1446.3.2 Shall have the words “For downhill mountain bicycleracing.”4. Marking the Test Line4.1 The test line is shown in Fig. 1 and
8、 shall be marked inaccordance with Test Methods F 1446.5. Conditioning and Number of Samples5.1 Shall be in accordance with Test Methods F 1446.6. Retention System Testing6.1 Retention system tests shall be performed before impacttesting.6.2 The ambient helmet shall be subjected to the positionalsta
9、bility (roll-off) test in accordance with Test Methods F 1446using a 4-kg drop mass from a height of 0.6 m.6.3 The retention system shall remain intact, and the helmetmust remain on the headform.6.4 The hot, cold, and wet helmets shall be subjected to thedynamic strength retention test in accordance
10、 with Test Meth-ods F 1446 using a 4-kg drop mass from a height of 0.6 m.6.5 The retention system shall remain intact without elon-gating more than 30 mm.7. Impact Testing7.1 The helmet can be impacted anywhere on or above thetest line with the curbstone anvil in any horizontal orientation.7.2 Use f
11、lat, hemispherical, and curbstone anvils in accor-dance with Test Methods F 1446, Figs. 7, 8, and 11.7.3 The helmet shall be dropped onto the flat anvil toachieve an impact velocity of 6.2 m/s 6 3 % (corresponding toa theoretical drop height of 2.0 m).7.4 The helmet shall be dropped onto the hemisph
12、erical andcurbstone anvils to achieve an impact velocity of 5.6 m/s 63 % (corresponding to a theoretical drop height of 1.6 m).7.5 Each helmet shall be given two flat anvil impacts andone each hemispherical and curbstone anvil impact in anysequence.7.6 Each impact shall be separated by a minimum of
13、120mm on center.7.7 The peak acceleration of each impact shall not exceed300 g.1This specification is under the jurisdiction of ASTM Committee F08 on SportsEquipment and Facilities and is the direct responsibility of Subcommittee F08.53 onHeadgear and Helmets.Current edition approved June 10, 2000.
14、Published August 2000. Originallyissued as F 1952 99. Last previous edition F 1952 99.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary
15、 page onthe ASTM website.3Available from Snell Memorial Foundation, 3628 Madison Avenue, Suite 11,North Highlands, CA 95660.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.8. Chin Bar Impact Testing (Applies to Full-FaceHelmets Only)
16、NOTE 1The equipment and procedures are described in 1995 Stan-dard for Protective Headgear for Use with Motorcycles and OtherAutomotive Vehicles.8.1 The ambient test helmet shall be subjected to the chinbar impact.8.2 The helmet shall be firmly mounted on a rigid base sothat the chin bar faces up an
17、d the reference plane is at 65 6 5from horizontal.8.3 Amass of 5 6 0.2 kg with a flat striking face of 0.01-m2minimum area shall be dropped in a guided fall so as to strikethe central portion of the chin bar within 25 mm of themid-sagittal plane.HEADFORM DIMENSIONSIZE X L/2 Y R S T UA 24.0 88.0 89.7
18、 47.5 23.0 142.0 84.0E 26.0 94.5 96.0 49.0 24.0 151.0 88.0J 27.5 101.0 102.5 50.5 25.0 160.0 92.0M 29.0 106.0 107.0 52.0 27.0 166.0 96.0O 30.0 108.5 110.0 53.0 27.0 170.0 97.0FIG. 1 Marking the Test LineF19520028.4 The impact velocity shall be 2.8 m/s 6 5 % (corre-sponding to a theoretical drop heig
19、ht of 0.4 m).8.5 The maximum downward deflection of the chin barmust not exceed 60 mm.9. Keywords9.1 bicycle; downhill; helmets; mountain; racingASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of
20、this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five
21、years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical com
22、mittee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).F1952003
