Suspension problem symptoms and potential solutions


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WingAdmin
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Suspension problem symptoms and potential solutions

Postby WingAdmin » Mon Jun 22, 2015 10:00 am



These are a list of common symptoms caused by suspension problems, and their causes:

ENTERING A CORNER

Symptom:
Steering is heavy and slow
Likely Cause:
Excessive trail
Possible Remedy:
Reduce trail by raising the rear ride height, adding rear preload, raising the fork tubes in the triple clamps, reducing front preload, or increasing triple-clamp offset

Symptom:
Steering is quick and flighty or unstable
Likely Cause:
Insufficient trail
Possible Remedy:
Add trail by lowering the rear ride height, reducing rear preload, lowering fork tubes in the triple clamps, adding front preload, or decreasing triple clamp offset

Symptom:
Steering is slow in side-to-side transitions
Likely Cause:
Center of gravity is too low
Possible Remedy:
Raise center of gravity by lowering the fork tubes in the triple clamps and raising the rear ride height an equal amount

Symptom:
Chassis is unstable in side-to-side transitions
Likely Cause:
Insufficient rebound damping is allowing the chassis to unload excessively
Possible Remedy:
Add front and rear preload damping

Symptom:
Chassis resists leaning while trail braking
Likely Cause:
Insufficient rake
Possible Remedy:
Increase rake by lowering rear ride height, reducing rear preload, lowering the fork tubes in the triple clamps, or adding front preload

MID CORNER

Symptom:
High-frequency chatter
Likely Cause:
Tire is out of balance or out of round
Possible Remedy:
Check tire condition

Symptom:
Footpegs or chassis parts drag
Likely Cause:
Center of gravity is too low
Possible Remedy:
Raise center of gravity by lowering the fork tubes in the triple clamps and raising the rear ride height an equal amount, or increase front and rear spring rates

Symptom:
Ride is harsh and rough
Likely Cause:
Suspension is packing or bottoming
Possible Remedy:
Reduce rebound damping, increase spring stiffness, or increase preload

Symptom:
Ride is bouncy and loose
Likely Cause:
Insufficient rebound damping
Possible Remedy:
Add front and rear rebound damping

Symptom:
Limited traction over bumps
Likely Cause:
Suspension is too stiff
Possible Remedy:
Reduce rebound damping, reduce low- or high-speed compression damping, or reduce preload

EXITING A CORNER

Symptom:
Bike runs wide or is unstable over bumps
Likely Cause:
Excessive squat is causing the front tire to lose traction
Possible Remedy:
Reduce squat by adding rear low-speed compression damping, adding rear preload, adding rear ride height, raising the fork tubes in the triple clamps, adding front rebound damping, or raising the swingarm pivot

Symptom:
Sudden loss of rear traction on acceleration
Likely Cause:
Insufficient squat
Possible Remedy:
Increase squat by reducing rear low-speed compression damping, reducing rear preload, reducing rear ride height, lowering the fork tubes in the triple clamps, reducing front rebound damping, or lowering the swingarm pivot

Symptom:
Excessive wheelies
Likely Cause:
Center of gravity is too high
Possible Remedy:
Raise the fork tubes in the triple clamps and lower the rear ride height an equal amount

Symptom:
Excessive chassis pitching
Likely Cause:
Excessive weight transfer
Possible Remedy:
Add rear low-speed compression damping, add rear high-speed compression damping, reduce front rebound damping, or lower the center of gravity

STRAIGHT

Symptom:
Wallows over rolling bumps
Likely Cause:
Insufficient compression damping
Possible Remedy:
Add low-speed compression damping

Symptom:
Bottoms out in depressions
Likely Cause:
Insufficient high-speed compression damping
Possible Remedy:
Add high-speed compression damping

Symptom:
Harsh over sharp-edged bumps
Likely Cause:
Excessive compression damping
Possible Remedy:
Decrease high-speed compression damping or low-speed compression damping

Symptom:
Wobble (high-frequency headshake) on smooth pavement
Likely Cause:
Insufficient trail
Possible Remedy:
Add trail by lowering rear ride height, reducing rear preload, lowering the fork tubes in the triple clamps, adding front preload, or decreasing triple-clamp offset

Symptom:
Wobble (high-frequency headshake) on rough pavement
Likely Cause:
Excessive squat is allowing the front end to unload
Possible Remedy:
Reduce squat by adding rear low-speed compression damping, adding rear preload, raising rear ride height, raising the fork tubes in the triple clamps, or raising the swingarm pivot

Symptom:
Weave (low-frequency headshake)
Likely Cause:
Insufficient rear damping is allowing the rear end to oscillate
Possible Remedy:
Add rear rebound or low-speed compression damping

Symptom:
Suspension gets progressively harsher over a series of bumps
Likely Cause:
Excessive rebound damping is allowing the suspension to pack down
Possible Remedy:
Reduce rebound damping

Symptom:
Chassis feels loose and loses traction or is unstable over rough pavement
Likely Cause:
Insufficient rebound damping
Possible Remedy:
Add rebound damping

BRAKING

Symptom:
Rear wheel comes off the ground or slides sideways
Likely Cause:
Excessive rear rebound damping is allowing the wheel to leave the ground
Possible Remedy:
Reduce rear rebound damping

Symptom:
Excessive chassis pitch
Likely Cause:
Insufficient damping to control brake dive
Possible Remedy:
Add front low-speed compression damping or add rear rebound damping

Symptom:
Excessive chassis pitch (cont.)
Likely Cause:
Center of gravity is too high
Possible Remedy:
Lower the center of gravity by raising the fork tubes in the triple clamps and lowering the rear ride height an equal amount

Symptom:
Front end feels harsh at maximum braking
Likely Cause:
Fork is bottoming
Possible Remedy:
Add front low-speed compression damping, add fork oil, add front preload, or increase front spring rate

Symptom:
Lack of feel from front end
Likely Cause:
Not enough weight is transferring to the front tire
Possible Remedy:
Remove fork oil, reduce front low-speed compression damping, or reduce front preload

Symptom:
Lack of feel from the front end (cont.)
Likely Cause:
Insufficient trail
Possible Remedy:
Increase trail by lowering the rear ride height, reducing rear preload, lowering the fork tubes in the triple clamps, adding front preload, or decreasing triple clamp offset

Symptom:
Front end bounces when the brakes are released, giving a momentary loss of traction
Likely Cause:
Insufficient front rebound damping
Possible Remedy:
Add front rebound damping



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NVSB4
Posts: 1130
Joined: Sat Mar 03, 2012 6:39 pm
Location: Arlington, Texas
Motorcycle: 1996 GL1500SE
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Re: Suspension problem symptoms and potential solutions

Postby NVSB4 » Mon Jun 22, 2015 1:59 pm

Wow, quite extensive troubleshooting.
Going to bookmark this just in case.
It's never too late to have a happy childhood!

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Chris


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