Shock Tuning:

The stock rear shocks on Honda's latest high end sport bikes are superb. They are so nice that I will be tuning mine rather than buy an aftermarket unit at this point. The spring and parts to do this cost less than $150. compared to over $1000 for an Öhlins or Penske. All I loose is ride height adjustability. We will see how important this turns out to be once the bike has been set up.

If I do choose to go with an Öhlins shock, the part number for the 2005 model 600RR is HO 502 (46PRXLS). It has a specified setup length of 313.5 +0/-6 mm and a 59.5mm stroke. The stock Showa shock measures at 310mm and by using customary sag numbers the ride height feels quite good with respect to squat. I am not convinced that an aftermarket shock needs to be purchased for the length adjustment feature at all. More data from other riders will show if this is true (let me know!!)

The shock should come apart similar to my 2003 CBR600RR Rear Shock Project.

I had an adapter ring made so that I could mount a Hypercoil spring to the stock rear shock. It is well worth it as now the stock shock is up to snuff. The aluminum adjustment ring seat on the shock also needed to be reduced from 2.380" to 2.250" to fit within the spring properly. The stock spring is 185mm long, has a rate of approximately 550 lb/in, and is preloaded 15mm in position #1. The stock shock is MEE-A01 and measures 310mm eye to eye. The preload mechanism moves 10mm in 10 steps.

At first I ran a 7" 630 lb/in (Labled 650, 3% off) 2.25" Hypercoil spring with 10mm of preload in position #8. I was able to get sag numbers of 5/free and 33/rider. The 686 lb/in (labeled 700) spring that I first put in the rear is perfect for 2 people, but too harsh for a single rider. Recently, I changed to a 600 lb/in spring preloaded to position #10 to give a little more comfort on the street. The wheel feels far more planted now as well.

Now that I got the spring worked out, I can start working on getting the damping right. I needed to baseline the oil so I changed out the stock oil with 100% Red Line Extra Light (Blue) (cSt 9.8).

Spring and damper, know the difference. Preload is for changes geometry, Spring is for changes in load, and the damper is for changes in velocity. It really is that simple.

The air valve is under the tamper cap. Drill a 1/4" hole about 1/2" off center.

Pry the cap off.

The Shrader valve.

Stock nitrogen pressure is 250 lbs. This is a bit high. Explanation in a few steps.

Push the cap in a little and pop the snap ring off.

Pull the bladder out of the canister.

This is the stock oil. I ended up collecting about 170 ml of this crap. Take a look at the massive amounts of foaming in this oil. This leads to cavitation. Air pressure is used to counter cavitation. That is why the pressure was so high. I will end up putting about 100-150 psi in the shock.

The two halves.

High speed valving.

The valve should be polished and ported. Original condition is on the right.

Compression face side.

Rebound face side.

I also changed the compression stack to match the heavier spring. It needs to be lightened up.

Stock shim stacks.

Compression Rebound
34mm x 12mm x 0.32mm 32mm x 12mm x 0.32mm
34mm x 12mm x 0.32mm 32mm x 12mm x 0.32mm
32mm x 12mm x 0.32mm 30mm x 12mm x 0.32mm
30mm x 12mm x 0.32mm 28mm x 12mm x 0.32mm
28mm x 12mm x 0.32mm 15mm x 12mm x 0.22mm
15mm x 12mm x 0.22mm 18mm x 12mm x 0.22mm
18mm x 12mm x 0.32mm 18mm x 12mm x 0.32mm
18mm x 12mm x 0.32mm 25mm x 12mm x 0.64mm
26mm x 12mm x 0.42mm  
26mm x 12mm x 0.42mm  

The new compression stack. A little better. Still needs some work.

'New' Compression
34mm x 12mm x 0.32mm
32mm x 12mm x 0.32mm
30mm x 12mm x 0.32mm
28mm x 12mm x 0.32mm
15mm x 12mm x 0.22mm
18mm x 12mm x 0.22mm
18mm x 12mm x 0.32mm
18mm x 12mm x 0.32mm
26mm x 12mm x 0.42mm
26mm x 12mm x 0.42mm

Good oil. Happy shock.

Fill it up and bleed the shock fully. Getting the bladder back in the canister requires removing the valve core until the bladder is mostly inside, then putting the core back in and giving it 1-2 psi to maintain shape.

Charge the shock with about 250psi of nitrogen and Install a steel valve cap over the valve to make it look like you know what you are doing.




  Oil Height
  Understanding Damping
  Low Speed Damping
  High Speed Damping
  Oil Locks
  Passive Elements
  Ride Height & Sag
  Squat & Jack
  Castor &Trail
  Understanding gearing
  Choosing a FDR gear
  Speedometer Recalibration
  Chains & Sprockets
  Motor Oils
  Oil Filters
  Oil Filter Testing
  Understaning The System
  The Throttle
  Power Comanders
  Gasoline & Octane
Rider Position & Controls
    CRG Levers
Breaking in a New Bike
Wave Rotors
Special Tools
  About Torque Wrenches
  Books to Own
2005 Honda CBR600RR
  All Crashed up
  Yoyodyne Slipper Clutch
  Speedometer Recalibration
  Yoyodyne Throttle
  HRC Throttle
  Tapered Roller Head Bearings
  PAIR / SMOG Removal
  Power Commander & Map
  Double Bubble Windscreen
  AIM Laptimer & Mount
  CRG Shorty Levers
  TCM Rear Rotor Modification
  1000RR Radial Master
  Factory Evo Star Shift Kit
  Frame Sliders
2001 Honda CBR600F4i
2004 600RR Shock Disassembly
Forums & Links
Dan Kyle Suspension Seminar
PVD Pro Slalom Trucks
Bearings & Lubrication
Skateboarding and the Law
Removing Skate Prevention Blocks
General Info
My Story
Shimano Mineral Oil
HollowTech II Bottom Brackets
Bicycle Chains
Chain Cleaning and Lube
Choosing One-Speed Gears
Wheel Components and Disk Wheel Lacing Patterns
GPS Dynomometer
Solid Models




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