# Show us your data acquisition setups!



## pvd (Jan 4, 2006)

I've just ordered some stuff to do a D/A rig on the big bikes. I'll have pots on each end and x,y,z acceleration and rotation. That should be enough to get some cool data. 100Hz isn't perfect but I'll be able to see and compare data on the trail.

http://www.graphteccorp.com/instruments/gl220/index.html
http://celesco.com/_datasheets/clp.pdf
http://www.sparkfun.com/commerce/product_info.php?products_id=10010

What have you folks done in this regard? What did you learn. Any good advice?


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## Walt (Jan 23, 2004)

*Rad!*

I have wanted to do something like that ever since I saw my uncles stuff as a teenager (he was chief mechanic/engineer (before those were separate things!) for Mears/the Unsers/Andrettis/Fitt/Lazier and others). Practice time for F1/F2/Indy/CART is always strictly limited, so he was one of the first to figure out that with some sensors and recording equipment, they could get more out of it (as well as do dry runs of suspension setup and such OFF the track by replaying/messing with the data and putting the car on hydraulics to simulate everything). He built a giant wind tunnel himself in the 60s or 70s in his yard in Indy - crazy cool stuff. I am in awe of the guy, and his shop would make even DWF drool (well, maybe not, but it's damn impressive).

One of my favorite stories of his is when he was codriving for Unser (probably senior? I don't remember) in the Mint 400 and kept hitting his head on the roof of the car and the back headrest (he was too short for the harness, he's only about five-two). Came away with a concussion and decided to do something about it - so he spent a few months messing with weird polymers until he found one he liked, and then all of a sudden nobody was getting concussions on a regular basis anymore because he'd invented padding that didn't rebound so fast.

Anyway, I'm way off topic.

It would kick ass to have this kind of capability for DH (or heck, XC) bikes. As of right now, though, I got nothin'. I'd love to see what you come up with!

On a related note (if they pull the trigger) I might build a fit cycle for the Boulder Center for Sports Medicine that will incorporate power output as well as being able to measure weight distribution (essentially the fit cycle sits on 2 scales that can be moved to simulate the locations of the wheels). That's a far cry from gathering real-time data on an actual bike/actual trail, though.

-Walt


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## DWF (Jan 12, 2004)

pvd said:


> I've just ordered some stuff to do a D/A rig on the big bikes. I'll have pots on each end and x,y,z acceleration and rotation. That should be enough to get some cool data. 100Hz isn't perfect but I'll be able to see and compare data on the trail.
> 
> http://www.graphteccorp.com/instruments/gl220/index.html
> http://celesco.com/_datasheets/clp.pdf
> ...


What do you hope to learn or what do you hope to derive from the data?


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## RoyDean (Jul 2, 2007)

get some strain gages.....


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## maelgwn (Dec 18, 2008)

Where are you mounting the IMUs. Right next to the wheel? Or higher up?

Mounting all the electronics will be fun! (Weather proofing, cabling and power supply ... on a DH bike)


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## Rody (Sep 10, 2005)

Pete, 

You are such a tech weenie...I love it :thumbsup: 

Have fun my friend,

rody


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## unterhausen (Sep 28, 2008)

RoyDean said:


> get some strain gages.....


I got a pair of frames that had been run into a garage on a roof rack. I cut them up and noticed they had strain gages on the stays. Never did find out who had them before the bike shop.

We did some work with the automotive guys here on campus with a Sick laser scanner measuring highway median profiles. We had a gps and synced up our data with their imu/gps.

I have the Sparkfun 9dof IMU, hoping to fly it sooner or later.


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## pvd (Jan 4, 2006)

DWF said:


> What do you hope to learn or what do you hope to derive from the data?


It should be able to give some quality information on how the spring and damping systems are functioning in different situations. I'm sure that spring rate choice will improve right away, especially in the rear. HSC, LSC, HSR, and LSR will be a lot clearer too. It's going to take some time to clearly read and make use of the data, but at the least there will be data to use rather than 'impressions'

I was tempted to jump onto a Rohig dyno initially but while that's a very nice tool, actual measurements on the bike are something that will make tuning a lot cleaner of a process.

The accelerometers and gyros should be pretty cool too. Asside from telling me what is happening to the bike while the suspension is in action, they will tell me a lot more about the maximum g's and lean angles on the bike. I realized last night that I'm going to need a 4th or 5th accelerometer in the system for putting close to the axles. I guess that could be interpolated from the pots, but once I'm up and running with this it shouldn't be too expensive to add. It's amazing how 10 lines can fill up quick.

I was even talking to a friend about how the accells and gyros could be cool on a road bike to improve cornering speeds by measuring the lean angles and g's. A little more area under the curve could add up to a bit of time.


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## pvd (Jan 4, 2006)

maelgwn said:


> Where are you mounting the IMUs. Right next to the wheel? Or higher up?


On the handlebar or seatpost. That should make it easier to adjust level and yaw.


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## Blaster1200 (Feb 20, 2004)

You may find the G Cog useful as well. 
http://www.g-cog.com/G-Cog.htm
http://www.g-cog.com/product_levels.htm


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## smdubovsky (Apr 27, 2007)

pvd said:


> I was tempted to jump onto a Rohig dyno


I've got a copy of one ~90% done as frustrated as I got w/ 29er fork damping. Its been in that same state for a year (too many projects, too little time)


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## pvd (Jan 4, 2006)

That G Cog is pretty neet. Too bad it's not made of steel.


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## unterhausen (Sep 28, 2008)

how do you use a shock dyno? Never fully understood the reason for them. I've built a fatigue machine, don't know why that wouldn't work for shocks.


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## RecceDG (Sep 4, 2010)

On cars at least, the shock dyno is one of the engineer's best friends.

See http://farnorthracing.com/autocross_secrets.html for a whole lot more info.

OP: You're about to learn a lot. In fact, my hat is off to you for braving down this path. I'm actually very surprised to see just how little data scraping is going on in the cycling world, because in the car world, we live and die by it.

Where you are going to run into some challenges though is locating the position of the bike in space, because the bike has so much more freedom of movement than does a car.

A suspension position pot tells you where the wheel is in relation to the frame - that gets you travel limits and spring forces. The change of suspension position over time gets you shock velocity (very important for damping) and shock acceleration (which I never found very useful but it might mean something in a bike context) That's all great stuff - essential, even - but it doesn't tell you anything about what the bike is doing in space.

On the car, because we had 4 wheels and usually at least 3 were in contact with the ground, we could trust that the roll angle would be tightly constrained. Indeed, we worked very hard to KEEP it constrained, due to issues with camber change in roll. So you can trust that the X accelerometer would represent left/right, Y would represent fore/aft, and Z would represent up/down. We'd get a little bit of X/Y error due to pitch and roll, but the small magnitude meant it was fairly easy to correct using the Z axis.

Car data systems routinely draw track maps using just accelerometer data. They need a little manual tweaking sometimes, especially if there was any sliding going on, but for the most part, you can assume that the individual accelerometers will match the representative axis in space.

On a bike... not so much. In fact, not at all. Even on a flat plane a bike leans to turn, which means that a corner is going to show up on both the X and Z axis accelerometers. Not just a little bit - a whole hell of a lot. And this is a mountain bike, so there is going to be a whole lot of pitch as well.

This is going to make your accelerometer data... challenging.

Here's how I would do it:

1. GPS. GPS will get you very good accuracy in 2D and some degree of accuracy in 3D. If you test in areas that has radar scanned elevation data, 3D can get even better (although capturing all the micro terrain - things like log rolls - will be exceptionally difficult) This at least gets you a decent reference track to help make sense of your accelerometers.

2. X/Y/Z accelerometers, located as close to the bottom bracket as possible

3. Linear pots on the front and rear suspension

4. A power meter, either in the crank or in the hub

5. An encoder on the cranks. Not just a 1-pulse-per-rev speed sensor, but an actual rotary encoder that can provide crank position

6. Some way of capturing gear position - probably linear pots on the shift cables

7. A strain gauge on the seatpost. This gets you seated/unseated and some feel for bump forces

8. Front and rear wheel speeds

9. A steer angle pot on the steer tube

10. Line pressure sensors on both brake lines

11. If there are lockouts on the shocks, and on/off switch for lockout position

12. Finally, some way of mapping the bike frame of reference to the world frame of reference. Something like a solid-state 3-axis gyro sensor. These exist, but the last time I went looking these were oh-my-god expensive.

Good luck!

DG


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## pvd (Jan 4, 2006)

I'm not going into that level of detail. It's mainly for suspension tuning and a few other numbers. More may happen later, that's why I went with a more flexible DA hub than standard motorsport gear. I can have max configureablity for home made sensors.

I do wish that I could pump GPS into the DA, but that would have added a major increase in cost. If it's that important I can gather GPS on another unit and time sync to two data streams together. It's a shame that the Garmin sample rate is so painfully low.

The IMU that I'm using should be good enough for what I'm doing. I'm more worried about my max sample rate. (http://www.sparkfun.com/commerce/product_info.php?products_id=10010)

http://en.wikipedia.org/wiki/Inertial_measurement_unit


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## jay_ntwr (Feb 15, 2008)

I use these sensors. I need left and right. All of the data is brought back via the central nervous system and crunched in the 'ole noodle. I'm censoring the other sensor 'cause I'm sure no one wants to see it.


















But seriously, Pete, seems like a nice idea--not sure that you'll get usable data, but nice idea. If you post some results, I suppose that'll prove that it does work. Theoretically, you should be able to do all of that w/ the kinematic tools (probably an add on package, been a while since I toyed with Dassault) in Solidworks--and it would be even more interesting to do that AND compare your tested results side by side. Ah, kinematics, what real MEs eat for breakfast in the morning.


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## pvd (Jan 4, 2006)

jay_ntwr said:


> seems like a nice idea--not sure that you'll get usable data, but nice idea.


You do understand that every form of auto and moto racing uses these systems because the rider is unable to give valuable information to make quality changes.


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## RecceDG (Sep 4, 2010)

pvd said:


> I'm not going into that level of detail. It's mainly for suspension tuning and a few other numbers. More may happen later, that's why I went with a more flexible DA hub than standard motorsport gear. I can have max configureablity for home made sensors.


Most DA setups will read analogue voltages and digital pulses, with some split between the number of analogue and digital inputs. You'll see something like 10 analogue, 6 digital or the like.

Digital are good for pulse sensors like hall-effect sensors (speed inputs) and for simple on-off switches, but I've also gotten crafty and used digital inputs to sample PWM controls like injectors, solenoids, and ABS systems.

Analogue can be used for almost anything that puts out a 0-5V signal. There are all kinds of sensors that do mapping of parameters to a voltage - some of them nonlinear to get better resolution in specific spots.



> I do wish that I could pump GPS into the DA, but that would have added a major increase in cost. If it's that important I can gather GPS on another unit and time sync to two data streams together. It's a shame that the Garmin sample rate is so painfully low.


You don't need anything faster than 1 Hz on the GPS - GPS isn't accurate enough to make faster sampling worthwhile - and the other inputs that the Garmin does (HR, Power, Speed, Cadence) also don't need any better than 1 Hz resolution.

Timestamp based synch is probably good enough, so long as you synch the clocks before starting logging. +/- 1 second will be good enough; you need the GPS track to make sense of the accelerometer data, not because you will be doing analysis.

Suspension position data is AT MINIMUM 100 Hz and 500 Hz is way better. You're going to be calculating first and second derivatives on these traces (to get you speed and acceleration) and you run into serious Nyquist issues if you sample too slowly. Plus I suspect that high speed (greater than 3 in/sec in my world) movements are really going to matter to you so you really need to be able to accurately capture these.

I also REALLY think you need that rotary encoder on the cranks... it can be an analogue signal where 0V is 12:00 and 4.99V is 11:59 (think a volume control with no limit stops) because you are going to want to be able to separate out pedal-induced movements from surface-induced movements. To do that, you need to know where the cranks are in their stroke. An encoder plus strain gauges in the crank arms would be even better....

What you are going to find is that collecting data will at first pose WAY more questions than it answers, and the answers to those initial questions will require more data.

It is true, for example, that just suspension position data - two analogue channels at 100 Hz - will give you enough to figure out limits (does the suspension bottom or top out? How often? For how long?) and set the minimum/maximum/mean/median shock speeds for analysis on the shock dyno. You can also see underdamping/overdamping, and with a little measurement work, you can figure out natural frequencies and damping ratios (although, man, with rider weight being the majority of the sprung mass, and with weight distribution front/rear shifting so much in response to rider position, it is going to be very hard to pin down the "real" NF) But this only answers the "what?" question, not the "why?"

If you can't map a specific WTF in the data to a bit of ground, you are going to have a hard time with "why?" There's a big spike in the suspension velocity trace: Obstacle? Root/Rock? Drop? Is the bike climbing/cornering/descending/crashing?

Etc.

DG


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## RecceDG (Sep 4, 2010)

pvd said:


> You do understand that every form of auto and moto racing uses these systems because the rider is unable to give valuable information to make quality changes.


Yup.

From personal experience, when it comes to setup changes, drivers are nowhere near as sensitive as they think they are, they adapt very quickly (such that "wonky" very quickly becomes "normal") and they are quite often Just Plain Wrong.

The number of times that the driver swore on his mother's grave that he did or did not do X, and was contradicted by the data....

DG


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## rustola (Jan 15, 2008)

RecceDG said:


> The number of times that the driver swore on his mother's grave that he did or did not do X, and was contradicted by the data....


Did somebody say Toyota sudden acceleration?


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## jay_ntwr (Feb 15, 2008)

pvd said:


> You do understand that every form of auto and moto racing uses these systems because the rider is unable to give valuable information to make quality changes.


Oh yeah, I understand that fully. I'm not arguing that point at all. I'm just wondering how much usable data you're going to get is all. S-M-D systems get really complex very quickly--and you've got more than one. A guy could do spend the better part of a Masters (and maybe a PhD) in transfer function hell working on this problem front and rear suspension. Still, cool project and I'm looking forward to seeing your data and analysis of that data.


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## xdpackin (Feb 5, 2007)

Sparkfun rocks!

You might also want to have a look at

http://www.stm32circle.com/hom/index.php

The company that makes the STM32 microprocessor has a devel team working on this cool open source hardware and software platform. They make hardware and software to get you started playing with your own projects and hopefully products that will use millions of their chips. The platform has lots of open source code published on the site with great examples for using the accelerometer and flash memory card. Its also got an LCD display. If you get really ambitions you can do you own PCB design and just mix in the open source hardware design they have published. You can make this run on a simple two side PCB that is printed at one of the many vendors online. Sparkfun also has some great articles about surface mount PCB fabrication. The AVR is also great if you want to do some hardware design.

The problem I've had with data in the off road truck world doing both lab style product testing and off road desert racing / rock crawling is just too much actual data gathered. Its not the type of thing where you can do an hour loop and sit down and start to understand what any of it means. Its easier to pick a good spot where you've got something challenging that will give you 3-5 minutes of really interesting data. Hit the same line with a new tune and give it a test. Then try to sync up some sort of a helmet camera so you can look at the data and bring it back to the approximate point where it came from in the test run.

Off road is a real PITA to figure out. Every F1 and Indy team is using high dollar data collection because they are operating with very very little suspension travel and highly understood track geometry. Hell, a 1/10 of a second is worth fighting for and they've got cash on hand.

Out in the desert where you've got anywhere from 12" to 36" of wheel travel test and tune is a bit different. I know the guys at King shocks and I've also dealt with Fox shocks as well for automotive parts. I've had long talks with the head guys at King and a friend's shop sells more King shocks than anybody. In addition I've had conversations with the guys over at the military side of Fox Shocks. They actually have a defense wing that tests and tunes military stuff

http://www.fox-defense.com/

In my experience, most of the off road tuning still involves a "guru" who shows up with a diesel truck and a gooseneck in tow full of springs, valves, and everything you need to rebuild the shocks. Then you spend as much time in the desert as you can muster dialing the truck in.

On road racing has plenty of variables and complexity. Off road is just crazy. Who knows what type of geometry you might see this season on a race track? Its always changing and the best racing series are adapting to mix long desert racing with serious slow going rock crawling trails. They've got triple bypass shocks that are position and velocity sensitive. Plus another shock with very light damping that holds the dual stacked springs to set a split rate. Then add in nitrogen charged bump stops and big tires at very low pressure going over highly irregular terrain and it is just easier and cheaper to get or become a guru.

I'm really hoping your efforts will yield some cool info. Even something simple like a speed bump could be used to get meaningful data. A flat then a speed bump followed by a flat will give you plenty of transient data to weed through. Add tearing down the shock and repeating a few times and I bet you can get somewhere pretty fast. Now if you only had the Mythbusters their to take high speed footage to sync up!


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## joshuagore (Oct 15, 2009)

For the past few years(although not this summer), I was the 'dag' guy for a race team(motorcycles and cars). We used mychron, and pi systems. I think the key is frequency of sensors and recorder. It helps that the motor-sports world is well supported with useful tools for analysis, helping to make data tell a more complete story graphically saves time and allows more changes over a race weekend.

I myself have considered fitting an AIM motorcycle rig(gotta use this because of lean) with linears up front and out rear and adding analog strain, steering position and yaw. I think this would tell a complete picture. Then maybe combining this data with a rear or side mounted camera.

In the motor-sports world my job became less tweaking the car and more tweaking the driver. I think because of the relatively unique conditions in mountain biking it will be a mixed bag.

Did the fork bottom there because spring rate, check the graph no, check the vid... ahh I see rider was hanging over the front... sloppy riding... etc...

Josh










Ok this is just pure car porn... can anyone guess the driver?


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## RecceDG (Sep 4, 2010)

Looks a little bit like Rahal from this angle... or has he lost all his hair yet?

Dual exhausts and I think that's a V8... but no wings. And the long arm, nearly parallel link suspensions are very 1970s... I'm not a vintage guy...



> Out in the desert where you've got anywhere from 12" to 36" of wheel travel test and tune is a bit different. I know the guys at King shocks and I've also dealt with Fox shocks as well for automotive parts.


Heh. I've always been a Bilstein and Penske guy myself... but all the Penske stuff started life as Fox (ever look at an 8100 series canister?)

DG


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## joshuagore (Oct 15, 2009)

RecceDG said:


> Looks a little bit like Rahal from this angle... or has he lost all his hair yet?
> 
> Dual exhausts and I think that's a V8... but no wings. And the long arm, nearly parallel link suspensions are very 1970s... I'm not a vintage guy...
> 
> ...


Rahal is correct. And It is a lotus powered Brabham... so its a 4. No data on that car obviously. In fact I have not seen any of his cars with data, but I am sure some of the f1 cars and indy cars in his collection have it.


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## RecceDG (Sep 4, 2010)

Yeah, now that I take a closer look at the first pic, I see what I thought was the other exhaust is on the other side of the tire... and may be the rear wheel of the jack.

That makes sense now; I couldn't figure out what would have an 8 and that suspension, but no wings.

Dig the crazy motion ratios on the shocks and springs... we don't do that any more.

Still, there is a Zen-like simplicity to these cars.

DG


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## joshuagore (Oct 15, 2009)

RecceDG said:


> Yeah, now that I take a closer look at the first pic, I see what I thought was the other exhaust is on the other side of the tire... and may be the rear wheel of the jack.
> 
> That makes sense now; I couldn't figure out what would have an 8 and that suspension, but no wings.
> 
> ...


I would trade that mess of madness for the suspension on my FV  That is too simple.


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## RecceDG (Sep 4, 2010)

Eeeeewww.... Formula Vee....

You poor bastard.

DG


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## joshuagore (Oct 15, 2009)

RecceDG said:


> Eeeeewww.... Formula Vee....
> 
> You poor bastard.
> 
> DG


Poor=Formula Vee no?


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## pvd (Jan 4, 2006)

xdpackin said:


> The problem I've had with data in the off road truck world doing both lab style product testing and off road desert racing / rock crawling is just too much actual data gathered. Its not the type of thing where you can do an hour loop and sit down and start to understand what any of it means. Its easier to pick a good spot where you've got something challenging that will give you 3-5 minutes of really interesting data. Hit the same line with a new tune and give it a test. Then try to sync up some sort of a helmet camera so you can look at the data and bring it back to the approximate point where it came from in the test run.


I agree. That's why when I found the DA recorder with display I decided to go in on this. I figured that I could focus on just a few sections that represent the several states of being on the bike and tune in the feild to get improvements.


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## dr.welby (Jan 6, 2004)

RecceDG said:


> 1. GPS. GPS will get you very good accuracy in 2D and some degree of accuracy in 3D. If you test in areas that has radar scanned elevation data, 3D can get even better (although capturing all the micro terrain - things like log rolls - will be exceptionally difficult) This at least gets you a decent reference track to help make sense of your accelerometers.


I can throw in some hard numbers on this. Your Z error on GPS is double your XY error. For a basic GIS-grade unit you're looking at 1 meter XY error, down to 1 foot if you're willing to drop about $10k. Anything less than that and you're looking at survey grade setups and you need to run your own base station so double your costs. Plus there's the software you'll need to post-process.

Off-the-shelf synthetic aperture radar only gives you a reading every 5 meters with a vertical accuracy of +/- 1 meter. If you had a lot of money to burn, you could shoot your test track with LiDAR for about $20k and get a surface model with 1 meter point spacing and a vertical accuracy of +/- 6".

Note that with all the above technologies, you need good visibility from the air so hopefully your test area doesn't have any trees on it.....


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## grisezd (Sep 20, 2007)

Hi Pete,

I'm glad to finally have something to add to the frame building part of these forums. I do data acquisition at a vehicle proving grounds in Ohio, and I had to learn much of it on my own. The mounting and wiring were not so difficult, but getting useful information from teh data was a challenge. Fortunately I had a period of time where I could design my own experiments to get my feet wet. 

Before you get too crazy with the motion pack, remember that your roll, pitch, and yaw sensors (being inertial) will not give you accurate angle information for more than a few seconds of a maneuver. If you ride straight at a cone, swerve around the cone, then straighten and stop the logger you can differentiate roll rate and get an estimate of the roll angle. If you do a slalom around 20 cones, or worse a lap through the woods, you'll find that the small noise you'll pick up from off-axis motions will cause your differentiated roll angle to get useless pretty quick. So I'd make that a project for when you run out of fun with the other sensors. 

If you emphasis is on suspension tuning I'd suggest setting up short, single hit test courses (maybe three stutter bumps, etc) and using vertical accels near the front and rear axles and a third one at the BB. A roll rate sensor could be helpful too. And if you can swing it some linear potentiometers (the string pots will likey whip around) on the fork/shock. Keep the test neat and short, and do it a lot with small changes. You can use your cycle computer to set entry speeds and keep a log. Next maybe you do a similar course in a tightly constrained turn. No need to look at lean angle, just increase speed over the radius from run to run. The data from these simple tests would keep me busy for quite a while. Another advantage to the short data files is that you can open 100hz files in excel easily. You can do quite a bit of analysis with that simple tool. 

Good luck with it, and let us see your data! At least the first trials to get the system dialed in anyway. I've always wanted to put a daq on a bicycle (motorcycles all the time, but no bicycles). 

Dennis


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## grisezd (Sep 20, 2007)

DWF said:


> What do you hope to learn or what do you hope to derive from the data?


That, I find, is the most useful question I can ask when a customer starts requesting large channel count data acquisition. Early on I was bit too many times when I'd glue all the gages, etc., take all the data, then find out the customer didn't know what to do with all the data.

My out for that, once I knew that he didn't know what he was looking for, was lots of pretty graphs. Useless graphs, but I'll bet they looked good in Powerpoint presentations!

Anyway, back to the topic, right? Pete, you've invited all of us geeks out!


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## lommen (Feb 3, 2011)

Sorry to bring up an old thread, but google led me here.

I'm about to start writing my masters thesis on "augmented sports" (a working title i just made up) and am currently exploring different options and solutions for data acquisition on bikes.

I'm curious to know if "pvd" managed to gather some useful data from his setup.


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## ade ward (Jun 23, 2009)

Back in the 90,s I used to work for tab sales who do the suspension designs for Marin and whyte

I used to run loggers on the team dh bikes we only had basin kart loggers with 2 analogue and two digital channels front and rear suspension and wheel and cadence speed

Downside was the logging rate was only 10 hz so we may loose a bit of the detail and have a problem with aliasing on the suspension pots

One test I used to do was lay an old wooden ladder on the ground and ride along at different speeds whilst logging the data. Good for looking for jacking up or down due to mismatch in bump and rebound damping

I have also done some testing on two post rigs at my local uni on this we mounted accelerometers on the rims hubs stem and seat tube to compare these positions this was done with a rider on the bike was held up with a single Rose jointed arm on the seat post


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## mickuk (Jul 6, 2007)

So how did you get on with the data PVD?

Was it 100 Hz actual sample rate (so you have reasonable amplitude data up to about 10Hz and frequency up to 50Hz) or 100Hz data after anti-alias filter / Nyquist (so actually sampled at a faster rate)?

What you really want is some Wheel Force Transducers  Don't think they do any for pedal bikes yet..... This was the last time I worked with some:-

sensor transducer system news


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## dr.welby (Jan 6, 2004)

I was a guinea pig on an instrumented mtb at UC Davis. If you want to search for literature, the professor on the project was Maury Hull and the PhD student was Dennis Wooten.


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## blackbart (May 1, 2004)

*Interesting...*

Any research using contemporary equipment?
https://mae.ucdavis.edu/faculty/hull/hull2.jpeg


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## dr.welby (Jan 6, 2004)

blackbart said:


> Any research using contemporary equipment?
> https://mae.ucdavis.edu/faculty/hull/hull2.jpeg


I would hope so, and I forgot about that bike - you could change the chainstay pivot location to change the antisquat on the back end.


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## Palardy (Apr 10, 2012)

*Bike Data logger*

I think you might be interested by this product: Paray's Bike Data Logger.
It's a complete bike data logger (suspension). You can do a research on google and you will easily find the website.

I'm the owner of this business. I hope it is "correct" to talk about this product here.

Palardy


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## blackbart (May 1, 2004)

Palardy,

It looks like a sweet interface - is this system and software based on off-the-shelf products or is it custom circuit boards, sensors, and software?


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## Palardy (Apr 10, 2012)

blackbart,
System and software has been design especially for mountain bike. It is not based on off-the-shelf products.

Palardy


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