2022 Kawasaki KX250 Suspension Owners Manual

2022 Kawasaki KX250 Suspension

Suspension

Introduction

• No area of machine adjustment is more critical than proper suspension tuning. An improperly tuned suspension will keep even the best rider from attaining the full benefit of his machine’s ability. Match the
• suspension to the rider and the course conditions.
• WHILE TUNING THE SUSPENSION, KEEP THE FOLLOWING IMPORTANT POINTS IN MIND:
• If the machine is new, “break in” the suspension with at least one hour of riding before making any setting evaluations or changes.
• The three major factors which must be considered in suspension tuning are RIDER WEIGHT, RIDER
• ABILITY, and TRACK CONDITIONS. Additional influences include the Rider’s STYLE and PO POSITIONING on the machine.
• Before changing the suspension settings, test changing your riding posture or position to check whether it is the cause of the problem or not.
• It is a wise practice to adjust the suspension to suit the rider’s strong points. If you are fast in the corners, adjust the suspension to allow fast cornering.
• Make setting changes in small increments. A little bit goes a long way, and a setting is easily overadjusted.
• The front and rear suspension should always be balanced; when one is changed, the other one might need to be changed similarly.
• When evaluating suspension performance, the rider must make every effort to ride consistently and to recognize the effects of his input. Such things as changes in rider position and increasing fatigue may
• lead to incorrect judgments about necessary adjustments.
• When the proper settings have been determined for a particular track, they should be written down for reference when returning to the same track.
• Lubricate the bearings in the swingarm and UNI -TRAK® linkage after a break-in and after every 3 races to prevent friction from affecting suspension performance.

Front Fork

Front Fork Oil Amount

The fork oil amount in the outer tube is adjustable. A change in the fork oil amount will not affect the air spring force much at the top of fork travel, but it will have a great effect at the bottom of it.

• When the oil amount is raised, the air spring be- comes more progressive, and the front fork action feels “harder” in the later stage of fork travel, near the bottom.
• When the oil amount is lowered, the air spring be- comes less progressive, and the front fork action does not feel as “hard” in the later stage of the fork
  travel.

Fork Oil Amount Effect on Fork Stroke

• A. Weight
• B. Fork Stroke
• C. Increase Amount
• D. Standard Oil Amount
• E. Decrease Amount

Changing the fork oil amount works effectively at the end of fork travel. If fork bottoming is experienced, raise the fork oil amount by 5 mL (0.2 US oz.) each.

Front Fork Oil Amount Adjustment-
Adjust the front fork oil amount (see Front Suspension section).

Troubleshooting Improper Settings

Listed below are some symptoms of improper suspension settings and the most likely means of correcting them. The proper settings can be achieved by applying the information given in this chapter in a scientific, methodical manner. This does not mean, however, you must be a scientist or trained technician to succeed. Simply take time to think about the changes you believe are necessary, check them against the symptoms and cures described here, make the changes in small increments, and take note of the changes and their effects.

Front Fork Improper Adjustment Symptoms-
Too Hard
Spring too stiff:
Rebound or compression damping improperly adjusted.

Spring too hard

• Fork oil amount too much Suspension stiffens at the end of the fork stroke:
• Fork oil amount to too much
• Fork air pressure high

Spring OK, but suspension too hard:

• Fork oil deteriorated
• Fork air pressure high

The front fork dives excessively during braking and deceleration:

• Fork oil amount too little
• Springs too soft
• Fork oil deteriorated
• Rebound and/or compression damping improperly adjusted.

Rear shock absorber improper adjustment symptoms

• Too hard

Suspension too stiff:

• Compression damping too hard
• Spring too hard

Spring OK but suspension too hard:

• Unbalance between the spring and the rebound damping (rebound damping too hard)
• Spring preload too hard

Bottoming occurs on landing after a high jump (otherwise OK):

• Spring preload too soft or compression damping too soft
• Spring too soft
• Shock absorber oil deteriorated

Determining the Proper Settings

Standard Settings

From the factory, the machine is set up for a medium-weight rider with intermediate riding ability. Hence, if the actual rider weighs considerably more or less, or if his riding experience and ability are much above or below the intermediate level, it is likely that a few basic suspension adjustments will be necessary.

Basic Readjustment of the Suspension

Suspension Tuning According to the Type of Course

Begin the actual on-track testing and evaluation after making these preliminary adjustments. Bear in mind the following points when readjusting the suspension.

• Always make changes in small steps.
• The rider must be consistent in evaluating suspension performance.
• A change in the front suspension might require one in the rear suspension and vice versa.

Front and Rear Suspension Compatibility Inspection

• Use this procedure to determine if the suspension is balanced reasonably well.
• Hold the motorcycle upright.
• While standing next to the machine, lightly pull the brake lever, place one foot on the footpeg closest to you, and push down hard. If the motorcycle stays level as the suspension is compressed, the spring rates are well balanced.
• Sit astride the motorcycle, take a riding posture and check that the machine is in a horizontal position. If one end drops noticeably more than the other, the front and rear are not compatible and must be readjusted to achieve a better balance.

Although this is one of the most effective adjustment procedures, suspension settings may vary depending on the conditions at the track and the rider’s preferences.

Front and Rear Suspension Troubleshooting

Front End Surges Downhill or During Acceleration Out of Corner

The front suspension is too soft.

• Increase the compression damping or rebound damping.
• Increase the fork oil amount.
• Use an optional harder spring.

Front End “Knifes” or Oversteers in Turns (Tends to Turn Inward)-

The front suspension is too soft.

• Increase the compression damping or rebound damping.
• Increase the fork oil amount.

NOTE

• Heavier or expert riders may need a harder spring.

Front End Pushes or “Washes Out” in Turns (Front Wheel Tends to Push Outward Rather than “Bite” in a Turn)

The front suspension is too stiff.

• Decrease the compression damping or rebound damping.
• Release some air from the fork tubes.
• Decrease the fork oil amount.
• Use a softer spring.

NOTE
Lighter or less experienced riders may need a softer spring.

Front End Does Not Respond to Small Bumps in Sweeping Turns

The front suspension is too hard.

• Decrease the compression damping or rebound damping
• Decrease the fork oil amount.
• Use a softer spring

Rear End “Kicks” When Braking on Bumps-

The rear shock absorber rebound damping may be low.

• Increase the rebound damping.

Rear Tire Does Not “Hook Up” Out of Corners (Lack of Traction Coming Out of Turns)

The rear shock absorber may be too stiff.

• Decrease the rear shock absorber spring preload.
• Decrease the high-speed low-speed compression damping
• Use a softer spring (lightweight rider only).

Fork Bottoms Off After a High-speed Jump (may be due to improper riding posture)-

The rebound damping is too soft or the spring is too hard.

• Increase the rebound damping.
• Decrease the rear shock absorber spring preload.
• Decrease the compression damping.

Front and Rear Ends Bottom Off After a High-speed Jump (harsh bottoming occurs once or twice per lap)

The front suspension is too soft.

• Increase the fork oil amount.
• Increase the front fork spring preload or use a harder spring
• The rear suspension is too soft.
• Increase the rear shock absorber spring preload or use a harder spring.
• Increase the rear shock absorber high-speed compression damping or use a harder spring.

NOTE

• Check the front and rear suspension compatibility after making any adjustments.

Rear End Feels Soft at Small Jump –

• Increase the spring preload up to maximum.
• Increase the rear shock absorber low-speed compression damping.

Rear End Feels Soft at Large Jump –

• Increase the spring preload up to maximum.
• Increase the rear shock absorber high-speed compression damping.

Rear End Bottoms After 3 or 4 Successive Jumps

• Decrease the rebound damping.

NOTE

• The rear shock absorber behavior on this machine may mislead some riders.
• The rear shock absorber bottoms (due to full stroke) when the spring and damping are overcome by the total weight of the machine and rider.
• A bottoming sensation (even though the machine is actually not bottoming) may be caused by machine weight and the inability of the rider to overcome an overly stiff spring or excessive damping.
• Observe the rear end jumps and try lowering the spring preload and damping if it does not approach bottoming