How do double adjustable shocks work?
03-10-2011, 05:52 PM
#61
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Ohlins and Penske shocks will do all three forms of valving. If you need stuff rebuilt or want a real custom shock, talk to Angelo at Anze http://www.anzesuspension.com.
and JRZ &moton cannot and provide only one single type (progressive?) by default in any of product lines they make, right?
03-10-2011, 06:21 PM
#62
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Regressive is the latest offering from Penske; if you take a look at their site I believe they have an article from Racecar Engineering available for download. If you look at the dyno graph, you'll see why it's called regressive....it appears to be some sort of elaborate blow-off valving. It is not the same as digressive damping, where the damping coefficient decreases as shaft velocity increases. Road car dampers do this to improve 'harshness', but at the expense of some hub mode control.
03-10-2011, 07:14 PM
#63
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Larry,
Dampers dissipate kinetic energy as heat; they work as a function of velocity (while springs exert a force as a function of displacement). This is true of a pure 'viscous' damper, which exerts a force in proportion to and in opposition to the velocity of an applied force. (As differentiated, for example, by 'coulomb damping', where the damping force is always present, the magnitude of the force is constant.)
Dampers dissipate kinetic energy as heat; they work as a function of velocity (while springs exert a force as a function of displacement). This is true of a pure 'viscous' damper, which exerts a force in proportion to and in opposition to the velocity of an applied force. (As differentiated, for example, by 'coulomb damping', where the damping force is always present, the magnitude of the force is constant.)
03-11-2011, 12:47 AM
#64
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so just to finally sort if out in my head - ohlin and penske can literally install whatever valving type one wants for each of 2-3-4 controllable adjustable valves?
and JRZ &moton cannot and provide only one single type (progressive?) by default in any of product lines they make, right?
and JRZ &moton cannot and provide only one single type (progressive?) by default in any of product lines they make, right?
Check out http://www.amfmotorsports.com/ohlinsporworks.htm. It explains how the system works pretty well.
03-11-2011, 10:15 AM
#65
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I don't know the other brands well, but it is done with the piston and shims, not the valves. The valves only control the initial movement before there is enough force to open the shims on the piston. It's the piston and shims that determine the overall shock behavior, not the valves.
Check out http://www.amfmotorsports.com/ohlinsporworks.htm. It explains how the system works pretty well.
Check out http://www.amfmotorsports.com/ohlinsporworks.htm. It explains how the system works pretty well.
Regards, Paul.
03-11-2011, 02:15 PM
#66
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Shim stack build and the shape of the piston are the determining factors in damper velocity vs force profile...shim stacks are noted for being non-linear, and typically involve a fair amount of trial/error. Hence the use of spool valves on the high-dollar units.... The shim stack and the amount of dish-in built into the piston determine how digressive the shock will be.
