Motorcycle manufacturers ship bikes from the factory with the understanding that any size or type of rider may end up on them, not to mention that their parts must be easily mass manufactured and assembled within a certain price point. The bike could end up almost anywhere around the globe on almost any kind of terrain. It might be raced, commuted, or just end up collecting dust in the back of someone's garage. The rider may be 150lbs, 280lbs, or two 180lb people of varied abilities. The factory has to maintain it's reputation (and safety record) by making sure that under any and all conditions the bike will perform fairly well if not very well. This is a very difficult task and the factories set up suspension in very odd ways to accomplish this. What this means to the end user is that the bike is good, but far from perfect. Thanks to the quality of modern bikes, it can take very little tuning to transform this compromised suspension system into one that melds rider and machine into a perfect system.

Suspension tuning has to follow a scientific process for getting close to an optimal state of tune. Getting the springs sorted out is the first step in setting up suspension. Damping follows this and cannot correct problems that originate in spring selection. The correct order of suspension tuning should be:

.5. Set approximate rear ride height.
1a. set Oil Height to the minimum height.
1b. Reduce rear shock nitrogen pressure to minimum spec.
2. modify the Oil Lock Piece - for race, eliminate or practically eliminate effectiveness of the oil lock piece. For street, reduce the effect of the oil lock piece if under hardest hit, more than 3mm of travel is left unused.
3. Spring Rate (& Sag) - this is done by changing springs (and preload).
4. Slow Speed Damping - this is done by changing oil viscosity and in some cases, slow speed orifice and needle size.
4.5 Straighten fork tube - these can be slightly bent. straighten the hell out of 'em.
5. High Speed Damping - this is changed by changing valves and/or shim stacks.
6a. Oil Height - this change tunes the last 1/5th of travel. Raise the oil height from the minimum if the fork is bottoming or practically bottoming.
6b. Rear shock nitrogen pressure should be raised in 25psi increments only to prevent cavitation.
7. Fine tune rear ride height for corner exit. Fine tune front fork clamp position for corner entry.
8. Re-sag bike.

Also, see how to do a disassemble a stock rear shock. HERE or HERE.

Since I have no need to rewrite what someone else has already said well enough, go to these web pages to learn the big picture regarding basic suspension set up. Return here to learn the fine details on how to make the changes work even better.

Info:

One of the best ways to learn about suspension is through discussion. Several forums on the net exist for this purpose, but the best one is the IBSF: Motorcycle Suspension Forum. It has recently been created by a group of very knowlageable people.

Yamaha YEC suspension Set-up

Honda HRC Suspension Set-up

www.sigmaperformance.com/suspensionarticle.html

Go-Star Racing - Suspension Set-up Guide: a very well written article on setting up your stock suspension.

Another suspension set-up page. HERE. It seems to be several articles put together.

A great article about getting onto the track from TrackDoD.org: Here.

Ohlins Shock Manual

Penske Shock Manual

You have to test and take note of your changes constantly. You can download a basic worksheet for notes HERE. Find a good road that will push you and your bike as hard as you can handle. You need to go to the extremes to find out what is happening. I choose a road that starts about 300 yards from my house: Bolinas/Fairfax Road. It goes up and over the saddle between Mount Tamalpais and Pine Mountain to the coast, just north of San Francisco. It has everything you could ask for from a road for motorcycling or cycling for that matter. 14 miles of utter insanity, almost no cars, and next to zero enforcement.

Photography

 

Motorcycles:
Introduction
Suspension
  Springs
  Oil Height
  Understanding Damping
  Low Speed Damping
  High Speed Damping
  Oil Locks
  Passive Elements
Geometry
  Ride Height & Sag
  Squat & Jack
  Castor &Trail
Gearing
  Understanding gearing
  Choosing a FDR gear
  Speedometer Recalibration
  Chains & Sprockets
Tires
Lubrication
  Motor Oils
  Oil Filters
  Oil Filter Testing
Fuel
  Understaning The System
  The Throttle
  Power Comanders
  Gasoline & Octane
Rider Position & Controls
  Feet
  Hands
    CRG Levers
  Windscreen
  Saddle
Breaking in a New Bike
Wave Rotors
Plumbing
Special Tools
  About Torque Wrenches
  Books to Own
2005 Honda CBR600RR
  All Crashed up
  General
  Break-in
  Forks
  Shock
  Gearing
  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
 
Skateboard:
PVD Pro Slalom Trucks
Bearings & Lubrication
Skateboarding and the Law
Removing Skate Prevention Blocks
General Info
My Story
 
Bicycle:
Shimano Mineral Oil
HollowTech II Bottom Brackets
Bicycle Chains
Chain Cleaning and Lube
Suspension
Choosing One-Speed Gears
Wheels
Wheel Components and Disk Wheel Lacing Patterns
General
 
GPS Dynomometer
 
Media:
Photo
Video
Sound
 
Resume:
Resume
Portfolio
Solid Models
References
 

 

 

 

This site has not been
updated since Fall 2006.

Since then, all new projects
have been place on my wiki
site.

If you like what you see on
this site, Make sure to go
to the wiki for even better
projects.

www.pvdwiki.com