Penske-racing-shocks 8900 Series User Manual

1Table of Contents Motorcycle ShocksInstallation ... 2N

108986 Series Compression Adjuster Parts List15 SP-16 Spring, (1460)16 OR-2222-B O-Ring, 2-222, Buna 7017 OR-2028-B O-Ring, 2-028, Buna 7018 HG-76____

11Compression Adjuster8986 Series Compression AdjusterCOMPRESSION ADJUSTMENTIn the state of low shaft velocities (i.e. corner entry, exit, and power d

128987 Series Compression Adjuster Parts List18 HG-76____* Housing, 8760, (Side Entry or Top Entry)19 SP-14 Spring, (A109)20 BA-125-ST Ball, Steel - 1

138987 Series Compression AdjusterLOW SPEED COMPRESSION ADJUSTMENTIn the state of slow shaft movement (i.e., corner entry, exit, andpower down), oil i

148760 Needle and JetThe 8760 jet and needle combination have been designed to give the user a broader and more linear range ofadjustment for bleed pa

15Disassembly / Assembly InstructionsDisassembly Instructions1. Back the rebound adjuster to full soft and depressurize the remote reservoir.2. Clamp

16Suggested MaintenancePRE RACE... Inspect for oil leakage.

17General Valving CharacteristicsThe damping characteristics of your shock are determined by the compression and rebound valve stackslocated on the ma

18A Guide To Damper TuningThe ultimate purpose of a shock is to work together with the spring to keep the tire on the track. Incompression (bump) to h

19A Guide To Damper TuningThe following setup procedures are basic recommendations for reaching an initial starting point usingdouble adjustable Pensk

2Your new Penske Racing Shock comes pre-adjusted at baseline settings. However, you must checkyour rear sag before you race! This is very important fo

20 Part #VS-AA AA .004 .004 .004 .004 ConstantVS-AAP AA+ .004 .004 .006 .006 ConstantVS-AM A- .006 .006 .004 .004 ConstantVS-A A .006 .006 .006 .006 C

21Preload Shim SpacersPart#.004 x .750 VW-23.006 x .750 VW-25.008 x .750 VW-27.010 x .750 VW-29.012 x .750 VW-31.015 x .750 VW-33.020 x .750 VW-00Part

22Flow Rate Through Multiple Bleed HolesHole 1 2 3 4 5 6 7 8 9Diameter Hole Holes Holes Holes Holes Holes Holes Holes Holes0.010 0.10 0.20 0.30 0.40 0

23Piston SelectionThis two stage piston combinesthe low shaft speed characteristicsof a linear piston with the blow offcharacteristic of a digressivep

24Linear PistonEach piston face has a dished surface, to preload the valve shims flat against the piston face. The standard dishing is 1° onboth the

25Digressive PistonDigressive PistonThe “high flow” design incorporates larger ports onthe face of the piston to increase the flow of oilthroughout t

26Velocity Dependent Piston (VDP)O.D. Base Shim01.235” for 55mm shocks01.200” for 45mm shocksCompression ReboundReboundFlowÇCompressionFlowÇThis graph

27Velocity Dependent Piston (VDP)1. Low Speed - Bleed, Nose Profile2. Digressive - Preload, Outer StackThe Velocity Dependent Piston (VDP) has the uni

28Damping AdjustmentsThere are three major ways in which you can vary the damping produced by the main piston: Shimstiffness, shim pre-load and the am

29Damping AdjustmentsFigure 3Figure 2

3Notes

30Dyno Graph Overview-1.20 -1.00 -.80 -.60 -.40 -.20 +.0 +.20 +.40 +.60 +.80 +1.00 +1.20Displacement (Inches)Quadrant 3+750+600+450+300+1500-150-300-4

31Dyno Graph OverviewAn easy way to help picture what is going on here is to relate the graph’s shape to what the dyno is doing to the shock. Thedyno

32Dyno Graph Overview1243OVAL (Force / Displacement)QUADRANT #1This is the beginning of the compression stroke. Where the graph crosses the zeroline (

33Dyno Graph Overview0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00CompressionBleed Chokes Off / Shims Activate (knee)Low Speed Bleed Bypass

34Notes

4Ride Height AffectsRide Height AdjustmentCAUTION!!!DO NOT EXCEEDTHIS LENGTH.470" (12mm)Going SHORTER with rear shocklength "eye to eye"

5Road Race Track Tuning: Symptoms and SuggestionsA. Change only one adjustment at a time, and send the rider out for evaluation and feedback.B. Take n

68900 Series Shock Parts List22 VW-99 Top Out Plate, 1.375 x .504*AS-89SBAssembly, 8900 Shaft Bearing(Includes items 23-28)23 BU-10DU06 Bushing, DU .6

78900 Series Shock SpecificationsBody Cap Clocking__ 90o Fitting __ 45o Fitting__ None180o135o90o45o0oExtendedLength(shortest)StrokeBody Length0o315o2

88981 Series Compression Adjuster Parts List12 BA-250-ST Ball, Steel - 1/4"13 SP-10 Spring, (TA2086)14 HO-87__* Hose (4" - 36" in 1&quo

98981 Series Compression AdjusterThe 8981 compression adjuster is located in the remote reservoirassembly. The remote reservoir serves as an extension