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- May 7, 2005
- Messages
- 6,795
On Koni shocks, which are rebuildable, you can vary the overall damping including the compression damping by varying the oil weight from the std 5wt. The disadvantage of this is that it also affects the rebound damping, now this is adjustable but in the search for the right compression damping you may end up losing the ideal rebound damping if it becomes outside the adjustment range. Or in the quest for the right compression damping you make the acceptable rebound range too narrow to be of use as adjustable.
There is a possible alternative.
Note this is untried and untested but follows normal practise.
This is the compression valve in the bottom of a 76 series Koni.
Left is complete valve from the bottom, on the right is a complete valve from the top.
The complete valve sits in the bottom of the inner damper tube, in rebound the one way valve in the top is open bypassing the compression valve. In compression the one way valve within the rebound valve is open so the rebound valve is by passed and the non adjustable compression valve is in play.
You can see the components of the compression valve in the centre.
Screw, Shim1, spacer, Shim 2, Shim 3 and locknut.
On a 76 series when you reassemble this stack you turn the screw until you have a gap of 3 thou between shims 2 and 3 using a feeler gauge and then you fix this setting using the locknut. On later versions a 3 thou spacer washer is used instead so no need for setting the gap.
What that does mean is that you can vary the compression damping rate by varying the 3 thou gap, less gap for more compression damping and more gap for less compression damping.
76 series are thin on the ground, suffer from a bump washer dissolving and blocking all the small damping holes, seals are no longer available.
So the 7610 series is the better option but !!
The issue with the same valve in the 7610 series is that it is not designed for easy access, the screw and locknut has been replaced with a pop rivet.
So if you want to confirm the same shim stack or similar is used you had better get you drill out. Myself I will just add it to future projects but go one further and see if a dual rate shim stack can be substituted for more functionality.
There is a possible alternative.
Note this is untried and untested but follows normal practise.
This is the compression valve in the bottom of a 76 series Koni.
Left is complete valve from the bottom, on the right is a complete valve from the top.
The complete valve sits in the bottom of the inner damper tube, in rebound the one way valve in the top is open bypassing the compression valve. In compression the one way valve within the rebound valve is open so the rebound valve is by passed and the non adjustable compression valve is in play.
You can see the components of the compression valve in the centre.
Screw, Shim1, spacer, Shim 2, Shim 3 and locknut.
On a 76 series when you reassemble this stack you turn the screw until you have a gap of 3 thou between shims 2 and 3 using a feeler gauge and then you fix this setting using the locknut. On later versions a 3 thou spacer washer is used instead so no need for setting the gap.
What that does mean is that you can vary the compression damping rate by varying the 3 thou gap, less gap for more compression damping and more gap for less compression damping.
76 series are thin on the ground, suffer from a bump washer dissolving and blocking all the small damping holes, seals are no longer available.
So the 7610 series is the better option but !!
The issue with the same valve in the 7610 series is that it is not designed for easy access, the screw and locknut has been replaced with a pop rivet.
So if you want to confirm the same shim stack or similar is used you had better get you drill out. Myself I will just add it to future projects but go one further and see if a dual rate shim stack can be substituted for more functionality.
