1、Designation:F195215An 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,the
2、 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.Studieshave
3、 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 recognizes the desir
4、abilityof 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 of this standard is
5、 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 standard,and should
6、 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 included in thisstand
7、ard.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 conducting the tests):This
8、 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 use.2.Referenced Documents2.1 A
9、STM 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 bicycleracing.”4.Marking the Test Line4.1 Th
10、e 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 F1446.5.2 For helmets with a chin bar,fiv
11、e 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 impacttesting.6.2 The ambient helmet shall be sub
12、jected 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 F1446 using a 4-kg drop mass from a height of
13、0.6 m.6.4 The retention system shall remain intact without elon-gating more than 30 mm.1This specification is under the jurisdiction of ASTM Committee F08 on SportsEquipment,Playing Surfaces,and Facilities and is the direct responsibility ofSubcommittee F08.53 on Headgear and Helmets.Current edition
14、 approved May 15,2015.Published June 2015.Originallyapproved in 1999.Last previous edition approved in 2010 as F1952 10.DOI:10.1520/F1952-15.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume i
15、nformation,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 7.Impact Sites and Projections7.1 Impact sites are described in Test Methods F1446.7.2 ProjectionsAny unfaired proj
16、ection 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.HEADFORMDIMENSIONSIZEXL/2YRSTUA24.088.089.747.523.0142.084.0C25.091.092.748.023.5146.586.0E26.094.596.049.024.0151.088.0J27.5101.0102.550.525.0160.092.0M29.0106.0107.052.027.0166.096.0O30.0108.5110.053.027.0170.097.0FIG.1 Marking the Test LineF1952 152 7.2.1 There shall be no fixture on the h