[Code of Federal Regulations]
[Title 16, Volume 2]
[Revised as of January 1, 2007]
From the U.S. Government Printing Office via GPO Access
[CITE: 16CFR1512.9]

[Page 560-561]
 
                     TITLE 16--COMMERCIAL PRACTICES
 
             CHAPTER II--CONSUMER PRODUCT SAFETY COMMISSION
 
PART 1512_REQUIREMENTS FOR BICYCLES--Table of Contents
 
                          Subpart A_Regulations
 
Sec.  1512.9  Requirements for protective guards.

    (a) Chain guard. Bicycles having a single front sprocket and a 
single rear

[[Page 561]]

sprocket shall have a chain guard that shall cover the top strand of the 
chain and at least 90[deg] of the perimeter where the drive chain 
contacts the drive sprocket as shown in figure 7. The chain guard shall 
extend rearward to a point at least 8 cm (3.2 in.) forward of the 
centerline of the rear axle. The minimum width of the top area of the 
chain guard shall be twice the width of the chain in that portion 
forward of the rear wheel rim. The rear part of the top area may be 
tapered. The minimum width at the rear of the guard shall be one-half 
the chain width. Such chain guard shall prevent a rod of 9.4 mm (\3/8\ 
in.) diameter and 76 mm (3.0 in.) length from entrapment between the 
upper junction of the chain and the sprocket when introduced from the 
chain side of the bicycle in any direction within 45[deg] from a line 
normal to the sprocket.
    (b) Derailleur guard. Derailleurs shall be guarded to prevent the 
drive chain from interfering with or stopping the rotation of the wheel 
through improper adjustments or damage.