Suspension Data Acquisition

How does one read those charts? I mean, I know what they're showing but there's a lot of data density there. Is the shape of the envelope what you're looking at?

Yeah mainly the shape of the lower envelope in the first image compared to the second. 

Yeah the shape of the curve can tell you how damped it is, eg an overdamped system might peak quite early in the travel then slow down while an underdamped bike will stay high or even accelerate further in to the travel. Can also be used to see how ramp up or bottom out systems are working and also rebound damping. Peak rebound speeds normally happen just after it reaches bottom out and is extending, so you can see if low rebound speeds are being caused by too much damping or if it isn't reaching far enough in to the stroke to be generating those speeds. Or if you are getting high speeds closer to the middle of the travel on the return stroke, it would probably be a sign of a soft spring using excessively light damping to achieve those speeds

Honestly I find the BYB plots quite messy and hard to see/filter the data clearly, I wish there was an easier way to customise the views in the software. I've used heatmaps in the past to show a similar thing because you can show the density a lot clearer and it doesn't get lost in a stack of lines. This is one example, the colourscale needed some work but I felt like it packed more info in to one view

Jumping in to make a couple of points.

1. You can't actually compare the first image to the second and reliably deduce an answer for most questions as you have said they are different trails, different riders, different suspension and surely different settings/setups, different durations and different environments. It doesn't help that the plots are different scales. These 2 images show absolutely everything different (maybe the ambient temperature was the same???), and so any difference in output could be from any difference in input.
2. Just because something is obvious to see in the plots, doesn't mean there's an obvious reason/fix. "Obvious from the second image that the rebound in the rear could do with speeding up". That is not a fact. The fact is that the front/green sensor sees higher rebound speeds than the rear/white sensor.

When you make comparisons you generally need to know what questions you're asking before you record your data, so that you can setup the inputs to give you outputs showing what you're wanting to compare. 

I'll take a stab and say that the trail in the first image had a lot more jumps. This is another factor that can make the plots look different without giving helpful info - why does it matter what the suspension/wheels are doing when they are airborne?

Duration (imagine a 2 minute vs a 5 minute descent/recording) is such a simple difference that changes what looks obvious, plus once you have too much data (too long duration) the plot gets overwhelmed and you just see a solid colour.

As @TheSuspensionLabNZ has pointed out, a heatmap helps give more understandable data. Even just having each plotted point mostly transparent is a simple improvement as you don't so quickly lose the data into a solid mass (limited to the scale of a single colour rather than across many like the heatmap). At least go the scatter over the line plots in BYB when trying to analyse so you're only seeing known data, the line versions are better when explaining what the data is recording.

Hi, 

New to telemetry, slowly learning but mainly leaning on BYB's auto tune function. Getting back into MTBing is a bit of a midlife crisis thing for me so I three years back on a bike and I still don't have a great feel for suspension. My feel is it's working or it's not hence the telemetry. 

I have been learning a lot through the auto tune function in BYB but I don't have the confidence to deviate too much so I was wondering how people felt about the auto tune suggestions for gravity / DH? It seems very much the school of fast, very little low speed compression with some high speed damping to balance. I am curious to if people deviate from the auto tune suggestions and if they think there is a better direction? I'm in SoCal so riding hard pack, dry, dusty, riding gravity / DH. Any suggestions would be greatly appreciated and would be amazing if anyone was willing to share numbers they like to hit.

My second question is I am curious to trying a damper first approach but I don't really know what direction to go in compared to BYB's suggestions. Is everything damped or does the rebound stay fast and only the compression is slowed? Again if anyone was willing to share any numbers in what they think is a good direction that would be amazing! 

Thanks!!!

OK, interested to see how y'all read this data. I've put my own conclusions and proposed tuning directions at the bottom...

Rider is a local first-year elite enduro racer who was top of the heap in U19s. Bike is a 2026 megatower with a Zeb and Super Deluxe coil. Trails are typical Perth Hills goodness: short, rough, rocky and moderately steep. Logged on my logger and visualized on data.syn.bike.

Summary stats for the three runs:


 

Graphs are pretty similar across the runs; this set is typical:

What stands out to me:
-Generally running pretty firm, especially in the front. Dynamic sag ~20% (F) / 25% (R). 
-Peak rebound speeds are very quick (but would come down a bit running softer spring rates).
-Rear compression max speed is very high, and the rear uses more travel than the front, even allowing for increased dynamic sag in the rear.
-Rear displacement histogram is skewed to the right relative to the front.

I wouldn't suggest changing anything until I'd talked to the rider about it, but my suggestions would be:
-Softer spring rates, esp. in the front
-More high speed compression damping in the rear.

Thoughts?

Here is my opinion (not saying in any way or form that it is the correct one):
 

• I agree, the setup looks pretty stiff on the air side of things.
• The compression speeds for both, the rear and the front seem pretty high to me. Are you sure that those are "good reads" or could the max be some sensor spikes? Had the same on my logger in the beginning and needed to crank up the filtering a bit.
• I think I would try 5-10 psi less in the fork and a 25-50 lbs softer spring in the back and see how the dynamic sag changes. If those get a bit higher I would then try to add some clicks of LSC and HSC to both shock and fork

All of that only, if the rider feels harshness. If not, he/she may just likes a pretty stiff setup. Then I would only add the LSC and HSC to give more platform to push from = gain more speed from pumping and setteling quicker after hard impacts.

Yeah  I was going to pretty much say the same things as @Treloid - both ends look pretty stiff, average position wouldn't be completely out of possibility on a WC DH bike but for enduro its very firm. 

And the peak speeds are definitely excessive - again a DH bike might peak around 8m/s, and very high compression speeds for enduro would be around 7. I remember Darren at Push saying somewhere the highest he has seen on a world cup was 9m/s. Rebound too - typically stiff springs with generate high rebound speeds and lower compression speeds but the fact that both are very high is probably some kind of noise in the sensor

I used to use a butterworth low pass filter to remove noise above around 30Hz, but eventually found I was just getting random dropouts where the sensor was reading 0 for a sample or 2. I would just snip those samples out and everything came back down to normal levels. If theres too many successive dropouts it would need slightly more careful smoothing, but it also means a problem with the sensor that needs fixing so I spent more time focussing on that instead

Now that's interesting. That data is filtered at 100Hz. Filtering at 30Hz brings those speed peaks down a lot - around 2000 in rebound, 3500 front compression, still ~6000 rear compression.

Trap for the unwary there.

Yup that sounds much more realistic! Proportionally the fork does look much stiffer, hence the compression speeds looking very low so I would soften that and/or reduce tokens first. The shock is maybe closer to optimum

To find out where the frequency cutoff is, you can run an FFT analysis and see where the signal drops away - typically suspension stops fucntioning somewhere around 20-30Hz (friction an inertia makes it hard to respond faster than that) so if theres noise or errors you will see the random spikes above the point where the rest of the data has tapered off. Set your filter somewhere just above that (or find the source of the noise and fix it). You can use a bandpass filter or just note which peaks disappear and see if there's a common condition - eg a damaged/bent potentiometer will have gaps that cause the output to drop to 0 instantaneously partway through the stroke. But interference and other noise can be a bit more random

"Honey, I shrunk the DAQ!"

First testride with the new Trazer V2.2 and the new Sensors.

About 50 % smaller

Trippled Battery capacity 

Standalone USB-C charging port

Beeper for UX support

Two Buttons with LED

Front Sensor is now a "standard" linear potentiometer with a carbon tube "casing"

Re-designed rear sensor that now has a bearing instead of plastic on plastic with small air gaps.

Works great!

Edit:

Another overlay video for those interested. Also with a pretty stiff fork setup regarding dynamic sag (21%) ;-)

https://youtu.be/1LCTslCTWLQ?is=856_7CwAul5PZ51R