Hi, & welcome aboard.
I'm not up on headshocks, but will advise you that if you want help you need to give folks a more detailed description of the problem, with as much specific information as possible.
What's the problem?
When does it happen?
How old?
Was it like this long? did it start suddenly? when? or did it degrade over time?
etc.etc.
The more info you provide, the more clues folks will have to analyze the problem and advise you. Alternatively you can always bring it to a Cannondale dealer, who should be famialir with their headshock system.
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