[tootrikky]

HSC = A spring preloaded poppet or valve stack. Spring preload can be adjusted by a threaded nut.
LSC = Bypass port of HSC consisting a needle that can be screwed in or out of the port to control flow

Wouldn't a shimmed valve stack usually be superior to a poppet in a compression valve? A valve stack can be tuned a variety of ways where as a poppet is limited to a regressive curve (has knee then goes linear) since the the poppet must be opened before fluid will flow. I am confused on this since the X2 platform has a bad rap among tuners and uses this design in its Twin tube dampers for compression (new X2 uses main piston stack for HSR, old uses poppet). However so does Push, although in a monotube damper. Push's stuff is well regarded and they have state of the art dyno, telemetry and a great rep so there has to be some merit to this design. I have owned several 1st gen X2' and an 11-6. The 11-6 was stellar, X2 mediocre on a good day. Seems like the Push's compression valve design is similar to most motocross monotube dampers with the addition of another circuit in parallel. I attached a picture of their compression valve and knowing what little I know, the valve on the left labeled "traditional" seems like the better system to me.

My guess is that in a monotube The main piston can control most of the curve, so the compression valve is only being used to tune the lowest and highest fluid speeds or basically fine tune the curves at the extremes. Twin tubes the compression valve plays a much bigger role on the overall curve ( not sure why) so that is why the poppet style is less than idea in the case. I believe Ohlins uses shims in their compression valves on their Twin tube shocks because of this.

 

[Cary]

Like most things in life there is more than one way to accomplish a goal and the execution and implementation is more important at the end of the day than underlying design.

 

[294037]

Every damper is only as good as the sum of all of its parts. Take a basic poppet valve with carefully selected port design, flow rates and corresponding bleed in conjunction with pressure balanced damping, low friction, and a durable chassis and it will outperform almost any shim stack valve on the trail. The high speed valve design matters very little if the rest of those things aren’t executed well

 

[Dougal]

Yes shims are better. Poppets are convenient for HSC adjustment on top of shims. A poppet by itself needs a selection of springs to tune and these are almost never available.

IMO monotube is far better than twin-tube for MTB. Twin tube can excel at great adjustment at low speed. Which we don't need.