Reducer / shock hardware wear Identification:
Reducers - Left (old & worn), Right (6 months old). While reducers will sometimes last many sets of DU bushings before they need to be replaced, it is important to check that they sit tight inside the DU bushings, especially when the bushings are new. If they press into a newly inserted DU bush with little to no effort or force - Your reducers are likely to be worn and will need replacing. Also, if the centre hole through the reducers are showing any sign of wear or ovalisation - They will require replacement.
Reducer / shock hardware types:
Here are the three common styles of mounting hardware found on the majority of mountain bikes. From Left to right - Fox 2-piece alloy, Fox 7-piece with crush washers and flanged polymer bushings, Rockshox 3-piece alloy. All three will come in several overall widths, and in varying inner thru axle diameters for your shock mounting bolts.
Different hardware is designed to be used with different bushing types. In the above photo, the Fox 2-piece hardware on the left and the Rockshox 3-piece hardware on the right are designed to be used with a metal DU bushing. The Fox 7-piece (and slightly older 5-piece) hardware is designed for use with Fox's polymer bushings. In the photo below, the traditional metal DU is on the left, and the newer style polymer bushings (installed as a pair per eyelet) are on the right. Notice the lip on the polymer bushings? Fox 7-piece (and 5-piece) hardware takes that lip into consideration of the total width.
Current Fox 7-piece and 5-piece hardware can be used in all Fox rear shocks and Rockshox rear shocks newer than 2008, but must be used with the polymer bushings. Some exceptions apply to proprietary OEM shocks such as Specialized Brain shocks.
Current Rockshox 3-piece hardware can be used in all Fox rear shocks and Rockshox rear shocks newer than 2008, but must be used with the metal DU bushing. Some exceptions apply to proprietary OEM shocks such as Specialized Brain shocks.
Fox 7pc Mounting Hardware - Click Here!
Bearing Mount Hardware
Certain frames may be able to utilise bearing mount hardware, which is offered in a 30mm x 8mm size. However Fox bearing mount hardware is NOT compatible with Rockshox rear shocks, and Rockshox requires a specific damper body in order to use their bearing hardware (pictured below).
Fox bearing hardware does not use a bushing in the shock eyelet.