1、Designation: F1952 10An American National StandardStandard Specification forHelmets Used for Downhill Mountain Bicycle Racing1This standard is issued under the fixed designation F1952; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision
2、, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers performance requirements forhelmets used by downhill mountain bicycle riders.
3、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 recog
4、nizes 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 F1446, except where notedherein.1.3 Partial utilization o
5、f 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 this
6、 standard, and should not be sold with anyindication that it meets parts of this standard.1.4 Headgear designed to comply with this and otherstandards may proclaim uses as certified by the manufacturer.1.5 The values stated in SI units are to be regarded asstandard. No other units of measurement are
7、 included in thisstandard.1.6 The following safety caveat applies to the chemical,mechanical, or physical, or a combination thereof, test methodsdescribed herein and is meant specifically for those performingthe tests (in an effort to provide them with notice to take theappropriate precautions when
8、conducting the tests): This stan-dard does not purport to address all of the safety concerns, ifany, associated with its use. It is the responsibility of the userof this standard to establish appropriate safety and healthpractices and determine the applicability of regulatory limita-tions prior to u
9、se.2. Referenced Documents2.1 ASTM Standards:2F1446 Test Methods for Equipment and Procedures Used inEvaluating the Performance Characteristics of ProtectiveHeadgear3. Labels and Warnings3.1 Shall meet the requirements of Test Methods F1446.3.2 Shall have the words “For downhill mountain bicycleraci
10、ng.”4. Marking the Test Line4.1 The test line is shown in Fig. 1 and shall be marked inaccordance with Test Methods F1446.5. Conditioning and Number of Samples5.1 Conditioning of the samples to be tested shall be inaccordance with the section entitled “Conditioning Environ-ments” in Test Methods F14
11、46.5.2 For helmets with a chin bar, five sample helmets arerequired for each shell-liner size combination.5.3 For helmets without a chin bar, four sample helmets arerequired for each shell-liner size combination.6. Retention System Testing6.1 Retention system tests shall be performed before impactte
12、sting.6.2 The ambient helmet shall be subjected to the positionalstability (roll-off) test in accordance with Test Methods F1446using a 4-kg drop mass from a height of 0.6 m.6.3 The hot, cold, and wet helmets shall be subjected to thedynamic strength retention test in accordance with Test Meth-ods F
13、1446 using a 4-kg drop mass from a height of 0.6 m.6.4 The retention system shall remain intact without elon-gating more than 30 mm.7. Impact Sites and Projections7.1 Impact sites are described in Test Methods F1446.1This specification is under the jurisdiction of ASTM Committee F08 on SportsEquipme
14、nt and Facilities and is the direct responsibility of Subcommittee F08.53 onHeadgear and Helmets.Current edition approved Aug. 1, 2010. Published September 2010. Originallyapproved in 1999. Last previous edition approved in 2009 as F1952 09. DOI:10.1520/F1952-10.2For referenced ASTM standards, visit
15、 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 page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-295
16、9, United States.7.2 ProjectionsAny unfaired projection extending morethan 7 mm from the helmets outer surface shall break away orcollapse when impacted with forces equivalent to those pro-duced by applicable impact-attenuation tests described inSection 9.7.2.1 There shall be no fixture on the helme
17、ts inner surfaceprojecting more than 2 mm into the helmet interior exceptoccipital stabilizers and foam fit pads.8. Impacting Schedule8.1 All impacting shall be performed in accordance withTest Methods F1446.8.2 Helmets shall be impacted with the anvils centered on orabove the test line described in
18、 Fig. 1.8.3 The test anvils can be oriented in any horizontal,centered position.HEADFORM DIMENSIONSIZE X L/2 Y R S T UA 24.0 88.0 89.7 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 1
19、70.0 97.0FIG. 1 Marking the Test LineF1952 1028.4 For full face helmets with a chin bar, a fifth ambienthelmet shall be tested in accordance with Section 10.9. Impact Testing9.1 Retention system testing shall be completed prior toimpact testing.9.2 The helmet can be impacted such that the theoretica
20、lcenter of impact described in Test Methods F1446 is anywhereon or above the test line with the curbstone anvil in anyhorizontal orientation.9.3 Anvils to be used are the flat, hemispherical, andcurbstone anvils in Test Methods F1446.9.4 The helmet shall be dropped onto the flat anvil toachieve an i
21、mpact velocity of 6.2 m/s 6 3 % (corresponding toa theoretical drop height of 2.0 m).9.5 The helmet shall be dropped onto the hemispherical andcurbstone anvils to achieve an impact velocity of 5.6 m/s 63 % (corresponding to a theoretical drop height of 1.6 m).9.6 Each helmet shall be given two flat
22、anvil impacts andone each hemispherical and curbstone anvil impact in anysequence.9.7 The theorretical center of each impact site shall beseparated from the theoretical center of other impact sites by aminimum of 120 mm.9.8 The peak acceleration of each impact shall not exceed300 g.10. Chin Bar Rigi
23、dity Test10.1 The chin bar rigidity test applies to helmets with a chinbar only.10.2 If a chin bar is present, it shall be tested in accordancewith the procedures in Test Methods F1446, Chin Bar RigidityTest, with an impact velocity of 2.8 m/s 6 5 % (correspondingto a theoretical drop height of 0.4
24、m), using a fifth ambientsample that has not been subjected to any other impact testing.The maximum deflection of the chin bar shall not exceed60 mm.11. Keywords11.1 bicycle; downhill; helmets; mountain; racingASTM International takes no position respecting the validity of any patent rights asserted
25、 in connection with any item mentionedin this standard. Users of 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
26、 responsible technical committee and must be reviewed every five 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 c
27、areful consideration at a meeting of theresponsible technical committee, 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 Internati
28、onal, 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). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).F1952 103
