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Benchmarking Premium Coil Shocks

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Skunk Works Suspension

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Discussion starter · #1 ·
An exercise in timing custom tuned coil shocks over a short section of downhill trail to see how they compare. The bike is a Specialized Enduro with an Intend Edge fork set at 175mm.
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Testing Protocol:
A rolling start in the same gear for each run with 5-6 pedals strokes off the line. The goal being to not pedal while on the track, but the gear is low enough that it's pretty much spun out once up to speed.
Runs are timed with a Freelap chip system for accuracy.
Each test session consists of running all shocks twice. The order in which the shocks are run is rotated for each session.
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R1 Test Shocks:
-Vorsprung Telum
-Marzocchi Bomber CR tuned by Avalanche Racing
-Marzocchi Bomber CR with a Fluid Focus Piston Kit (self installed)
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All shocks were tuned specifically for the Specialized Enduro and a 475# spring, and then ridden and settings bracketed to find the optimal setup prior to timed testing.

The Test Track:
Mostly downhill, with some turns up top and a fair amount of loose and embedded rock. A good test for maintaining momentum and staying off the brakes.


Round 1 Results:
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Fluid Focus takes the win for this round with more to come.....
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Discussion starter · #3 ·
A shock dyno will show how much damping force is generated at certain shaft speeds, as well as the adjustment range the clickers will provide. It can also point out issues with performance such as hysteresis and fade. But it cannot necessarily tell you how shock A will perform vs shock B with a certain frame/rider/track unless there is lots of prior testing data to pull from.

The end goal of this exercise is to take the "fastest" shock and "slowest" shock (based on the timed runs), and then try to determine what accounts for this difference in performance.

Next step is on the bike data acquisition to see what the shaft speeds and displacements are for the shocks when run on the test track. Then run the shocks on a dyno to see what forces are being generated at these shaft speeds.

Why is shock A faster than shock B?
Does it develop more or less compression and rebound damping? What does each damping curve look like? Is the dynamic sag higher or lower? Is the max travel used more or less? I have lots of questions. :)
 
#10 ·
Pretty cool! I’d love to hear your remarks on the subjective feel of each as well as your objective findings. Also, is there a way to blind the test? For example, have someone else mount each shock and cover it up so you don’t know which one you’re using during the run? Great effort!
 
#11 ·
DrDon said:
I’m guessing inventory costs because of multiple variations, dealership status, people backing out.
Click to expand...
I just see one piston on the FF site. They buy 100 210x55 shocks, mod them all in a day, and sell them for a much greater profit than modding one at a time as there is time saved doing them all at once and they get to keep the profits from the base retail price of the original shock. Get an order in, toss in a travel spacer for x50 or x52.5, ship it out.
 
Discussion starter · #12 ·
Bikedog22 said:
Nice writeup. Is there an imbalance running an air fork?
Click to expand...
Possibly, but I have been riding the fork for quite some time and it seems pretty balanced. I wanted to keep everything the same apart from the rear shocks for this scenario. At some point the full data setup will go on to get everything dialed in and really see what is happening with fork/shock/chassis.


bmwpowere36m3 said:
Interesting testing, just going off time seems a bit of a wash... 2 secs on a 2 minute run is less than 2%. So maybe its more subjective on what feels right and fast... thus giving you confidence.
Click to expand...
True, that was part of the idea. Measuring subjective feel vs actual time. Each shock in this test was setup by feel, and bracketed to get what I thought was the best performance. No timing or data acquisition was involved with setup, it was 100% subjective.
As the test track is not difficult to ride, and very repeatable, the thought was that the shock that is the most efficient in the rough and/or most confidence inspiring (less braking) will have the best time. Subjectively, the Avalanche shock was the most comfortable overall, but felt a touch more nervous and loose in the fast and rough sections. It was surprising the times were consistently slower.



Nat said:
Pretty cool! I’d love to hear your remarks on the subjective feel of each as well as your objective findings. Also, is there a way to blind the test? For example, have someone else mount each shock and cover it up so you don’t know which one you’re using during the run? Great effort!
Click to expand...
A fully blind test with no knowledge of the times until the very end would have been the best. It just wasn't possible to do solo. The Vorsprung and FF shocks both had a very similar feel, and it was interesting to see that their times were consistently different.
I recorded subjective notes after each run before checking the time. Going into the test I thought the results would be the opposite, the Avalanche tuned shock is a hovercraft where it just smooths everything out. In general it is the most comfortable, the other two had more feedback thought the pedals which I thought would translate into harshness at speed. But on the test track this was not the case with the Avy shock actually feeling a bit more nervous in the rough when compared back to back with the others.
 
#13 ·
TylerVernon said:
I just see one piston on the FF site. They buy 100 210x55 shocks, mod them all in a day, and sell them for a much greater profit than modding one at a time as there is time saved doing them all at once and they get to keep the profits from the base retail price of the original shock. Get an order in, toss in a travel spacer for x50 or x52.5, ship it out.
Click to expand...
But then I wouldn’t get the individualized bespoke level of love that I and my shock deserves.
 
#14 ·
TylerVernon said:
These companies (Fluid Focus and AVA) are so odd. They offer all these mods for the Bomber CR but you can't buy one from them already modded.
Click to expand...
That’s not true about FF - if you email them and purchase through them they give you a discount (as opposed to buying your own Bomber and mailing it to them)
 
#19 ·
Skunk Works Suspension said:
Each test session consists of running all shocks twice
Click to expand...
If you want meaningful datas, you need to ride each shock much more than that.
If I look at your results, you are trying to rate shocks with a 2s difference, while you can have up to a 4s difference for a single shock the same day. You need to have enough data to measure variance so you can tell if your results are significant or not.
 
#20 ·
bmwpowere36m3 said:
Interesting testing, just going off time seems a bit of a wash... 2 secs on a 2 minute run is less than 2%. So maybe its more subjective on what feels right and fast... thus giving you confidence.
Click to expand...
2% is a typical podium placing gap in most UCI downhill races. If that's the target audience of this upgrade, it probably matters. Those riders have tweaked their suspension to 95% efficiency already. Closing that last few percentage points translates to $$$. For the rest of us mere mortals riding around with suspension that's 80% correct, simply finding better settings within the factory tune will likely yield more dramatic improvements. Cool data though.
 
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