Penske Racing Shocks 8975 User Manual

Main Office

150 Franklin St. • P.O. Box 1056

Reading, PA 19603

[phone] • [phone] Fax

PS-8975-DRAG (Double Adjustable)

TECHNICAL MANUAL

PS-8975-DRAG (Double Adjustable)

2010/2011

Table of Contents:

Introduction p.3
Terminology p.4
Getting Started p.5
Setting Ride Height p.6
Adjusters p.7
Setting Adjusters p.8
Adjustment Range (general) p.8
Adjustment Range (rebound) p.9
Adjustment Range (compression) p.10
Factory Settings p.11
Track Tuning p.12
Assembly p.13
Parts List p.15
Warnings p.17
Troubleshooting p.17
Technical Support p.18

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PS-8975-DRAG (Double Adjustable)

2010/2011

Introduction

Thank you for purchasing Penske Racing Shocks 8975 Series double adjustable shock absorbers.

The 8975 Series is the latest addition to Penske Racing Shocks successful product line-up. The most
economical multi-adjustment shock, the 8975 Series utilizes standard Penske Racing Shocks parts
already known for their quality and repeatability.

Every Penske Racing Shock is 100% hand built and dyno-tested for the best performance and customer
satisfaction. We stand by our products and routinely assist customers in getting the best performance
from their shocks. The same components in the 8975 Series are used all over the world at the highest
forms of Motorsport.

All of the fundamental attributes found in any Penske Racing Shock have been incorporated into the
8975 Series including:

 55mm bore size, compatible with a wide array of piston types.
 Low-friction shaft and piston seals.
 Hard anodized, 6000 series aluminum bodies and components for superior durability,

performance, and repeatability.

 Hard-chromed 4130 main shaft with rolled threads for strength, durability, and low breakaway

friction.

 Durable ACME threaded body for quick adjustments to spring preload (.100” per turn).
 Simple, in-line design for lightest weight and ease of installation.
 Winning heritage – Penske Racing Shocks continue to help customers win races and

championships in all forms of Motorsport.

 Made in U.S.A. – The 8975 Series has been 100% designed, machined, assembled, and tested for

quality in the United States.

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PS-8975-DRAG (Double Adjustable)

2010/2011

Body

Compression Adjuster

Ride Height Adjuster

(coil-over applications only)

Spring

Spring Retainer

Rebound Adjuster

Clevis

Shaft Bearing

Shaft

Terminology:

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PS-8975-DRAG (Double Adjustable)

2010/2011

Getting Started:

Shocks are sent from the factory at recommended start settings for the application in which they were
ordered - pressurized and ready to go.

Some basic tools needed to adjust the 8975 Series shocks are:

1.) Allen Key (3 mm): to secure ride height adjuster after setting ride height with springs.

2.) Pre Load Adjuster Tool: to make ride height adjustments to spring perch.

3.) Allen Key (5/32”): to make compression/rebound adjustments.

1.) 3mm Allen Key to Lock Perch 2.) Pre Load Adjuster Tool

3.) 5/32” Allen Key for Compression/Rebound Adjustment

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PS-8975-DRAG (Double Adjustable)

2010/2011

To Set Rider Sag:

Shocks will arrive from the factory with ½” of spring preload. Rider sag must then be set AFTER installing

the shock on the bike. After sag is set, tighten the 2 Allen screws (3mm Allen) in the spring perch to
prevent loosening. Avoid over-tightening – nip-up gently to avoid damage to the body threads.

STEP 1

1. Without a rider on the bike, have an assistant lift the rear of the motorcycle until the rear wheel

is off the ground slightly. One person should hold the front of the motorcycle, straddling the
front tire.

2. Measure the distance between the axle centerline and a convenient location on the rear sub

frame or tail.

3. Record this measurement as "A". Your Bike:__________

STEP 2

1. One person should hold the front of the motorcycle, straddling the front tire.

2. Have the rider, wearing all of their gear, sit on the bike in a riding position.

3. The third person should then measure the distance between the axle centerline and a

convenient location on the rear sub frame (same locations used in Step 1).

4. Record this measurement as "B". Your Bike:__________

STEP 3

1. Subtract "B" from "A". This number is your rider sag. Target: 12mm-24mm Rider Sag.

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