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Old 01-08-2013, 11:02 PM   #4252
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Joined: May 2006
Location: Melbourne, Australia
Oddometer: 1,763
Originally Posted by JNRobert View Post
I'm no engineer but, would there be diminishing returns as you move further out on the damping curve due to the limitations of the spring itself (it also has a finite operating range)? Or maybe conventional damping even on the Ohlins is operating in an envelope smaller than is ideal

I think it's the latter. Only so much you can do via forcing oil through a hole past a bendable shim. So the conventional damper is valved for the expected conditions and the performance required. The range shown on the "traditional" chart could be moved up or down the force scale (Y-axis) by changing components, but the range of adjustment would remain narrow.

BTW: the X-axis represents the axle deflection rate (or speed) in metres/second, while the Y-axis is the resistance from the damping, in Newtons. You will notice that max compression damping at max deflection rate is about the same on either side: i.e., the charts show similar capacity to soak up really big hits.

Where the contrast is greatest is in the capacity to control the lower end and middle of the deflection-rate range, and also in the ability to show very little compression resistance across the board - including to a very sharp but low-amplitude hit.

That is where the Skyhook can control braking and acceleration forces much better (using a lot of damping at the low-speed end), and also where it can allow the wheels to float over sharp corrugations and the like that want to shove the axle around fast but not very far.

On those sharp little hits, the conventional shock would be working in the upper (right) end of the speed range, and so will be working hard to resist them, however it is adjusted, and throwing the rider around. Skyhook (in theory anyway) has the option of letting the wheel move easily until it works out whether the hit will be sustained.

One thing the chart doesn't tell us tho is whether by "traditional" suspension it means the commonly used de Carbon system, or the TTX system Ohlins specced for the rear of the Multi. Ohlins claims that the TTX also has a much wider adjustment range than conventional de Carbon style shocks. So perhaps that is part of why the Ohlins bike stood up so well in those MCN tests.

I am looking forward to hearing more as owners try these. And of course, there remain also the serviceability, longevity, replacement-price and spring choice (if any) questions. Those charts suggest there is plenty of rebound capacity to cope with a stiffer spring, should one be needed for some applications.
Sorting out the S4Rs Ohlins shock: click here.
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