Introduction

With respect to data collection using the Motion Instruments (MI) system, there are two types of bikes: 1) Bikes that you can attach the sensor in line with the rear shock, 2) Bikes that you cannot attach the sensor in line with the rear shock. When quantifying how the bike interacts with the ground, we need to be able to calculate axle speed in the y (up/down) direction. This is easy with the fork, but for the rear axle, we need to measure anything that moves and use a lookup table to calculate the instantaneous position of the rear axle. 

Most of the bikes we have on our vendor list, we get the exact kinematic data directly from the manufacturer. In our MIBD (motion instruments bike definition) file, we describe the bike geometry in a very simple way. The file contains information like head tube angle, fork travel, rear axle travel, and a table that describes the curve. The information that we need is simply data points that describe the relative motion between the shock and rear axle vertical position. As the rear axle moves up, the shock is compressed. In short, we are left with a simple table that looks like this:

Shock Position (mm), Rear Axle Vertical Position (mm)

0, 0

0.1, 1

0.2, 2

.

.

.

.

Fully Compressed ShockPosition (mm), Final Rear Axle Vertical Position

Please note that we are only interested in the relative motion. We don’t care that the shock eye to eye is going down, only that it moves x mm and the corresponding rear axle movement in mm. 

Measuring the bike to make a file for MotionIQ Pro

As an example, we are going to pick a difficult bike to mount a sensor to the shock and measure it to use the MI system. Let’s pick the Propain Rage as an example. 

It will be difficult to get a sensor mounted on this shock. It’s literally buried in the frame. However, there is plenty of room under the top tube to mount a sensor. In this position, we can just measure the upper rotating link. 

Using a couple of simple stick ons we provide, you can easily mount a sensor in this location. Once the sensor is mounted, you want to make sure that the sensor will measure all of the motion without bottoming out. You may want to take the spring off and just install the damper and look to see that the sensor has enough clearance to measure the entire stroke range without bottoming out the sensor. If this is verified, you can follow these simple steps.

1. With the shock mounted with the spring compressed, turn the bike upside down.
2. Remove the rear wheel, put the rear axle back in the frame. You will measure from the axle to the floor.
3. Measure the distance from the rear axle to the floor.
4. Measure the shock eye to eye

Now this is where things can get difficult based on the tools you have in the garage. We use a floor jack to lower the rear axle in 5-10mm increments until we capture the range of motion for the rear axle. 

1. Remove the shock from the frame
2. Place a floor jack under the rear axle and pump up the jack > than the rear axle motion. IE for a 150mm bike, raise the jack 160 mm or so. 
3. Place a piece of wood between the jack and rear axle. 
4. Now adjust the jack so the rear axle is exactly the distance to the floor in Step 3
5. Drop the jack 5-10 mm
6. Measure the distance between rear axle and floor, shock eye to eye
7. Repeat steps 9 & 10 until you hit the rear travel distance as specified by the manufacturer

You should have a list of values that looks like this:

Measurement	Rear Axle to Floor	Sensor Eye to Eye		Relative Rear Axle	Relative Sensor
M0	279	87.0		0	0
M1	269	86.0		10	1.0
M2	259	84.0		20	3.0
M3	249	82.1		30	4.9
M4	239	80.0		40	7.0
M5	229	77.9		50	9.1
M6	219	75.6		60	11.4
M7	209	73.3		70	13.7
M8	199	70.4		80	16.6
M9	189	68.8		90	18.2
M10	179	65.8		100	21.2
M11	169	63.0		110	24.0
M12	159	60.0		120	27.0
M13	149	57.0		130	30.0
M14	139	53.0		140	34.0
M15	129	49.8		150	37.2
M16	119	44.8		160	42.2
M17	114	42.5		165	44.5
M18	119	41.0		170	46.0
M19	124	39.5		175	47.5
M20	129	38.0		180	49.0
M21	134	36.5		185	50.5
M22	139	35.0		190	52.0
M23	144	33.5		195	53.5
M24	149	32.0		200	55.0
M25	154	30.5		205	56.5
M26	159	29.0		210	58.0
M27	164	27.5		215	59.5

The table on the left is the measured values, the table on the right is the relative motion of the rear axle and sensor starting from 0 and going up to max movement. Once all of the measuring is completed, now you can create an MIBD file. This is just a simple text file that you can make with any text editor. All you have to do is change the file extension to .mibd. This will make it easier for the MotionIQ app to pull in the file.

Your final Propain Rage MIBD file should look like this:

<-------------------------------------------------------- File Start ------------------------------------------>

section, description

manufacture, Propain

model, Rage

year, 2022

suspension, softail

fork travel, 200

HA, 63

section, linear sensor

0 , 0

1.0 , 10

3.0 , 20

4.9 , 30

7.0 , 40

9.1 , 50

11.4 , 60

13.7 , 70

16.6 , 80

18.2 , 90

21.2 , 100

24.0 , 110

27.0 , 120

30.0 , 130

34.0 , 140

37.2 , 150

42.2 , 160

44.5 , 165

46.0 , 170

47.5 , 175

49.0 , 180

50.5 , 185

52.0 , 190

53.5 , 195

55.0 , 200

56.5 , 205

58.0 , 210

59.5 , 215

<-------------------------------------------------------- File End------------------------------------------>

To import the file into your pro app, just follow the instructions laid out in this youtube video:

(88) How to Import a Recording - YouTube

Measuring a bike using the free MotionIQ app

If you will not be needing a full motion curve for the bike, it’s best to use the Generic Soft Tail bike. For this, all you need to know is the final sensor position when the bike is fully compressed. 

1. Measure the sensor eye to eye
2. Remove the spring on the shock and install it back on the bike, or if you have an air shock, remove all the air
3. Have a rider stand on the pedals with all of their weight
4. Measure the sensor eye to eye
5. Subtract the measurement in step 4 from step 1.

In the app, when creating the bike, put in all of the information about the bike including fork travel, head tube angle, etc. For rear axle travel, put in 215 for the Propain Rage. For the shock value, put in 59.5 (bike fully compressed). 

Conclusion

It is important to use data analysis when optimizing your bike suspension setup. Without data you are just guessing. Best practice is to use the bike leverage ratio from the manufacturer. When this data is not available, you can just mount the sensor to capture motion anywhere on the bike that gives you a lot of motion relative to the sensor stroke range. 

Pick something that moves close to the upper range of motion of the sensor without bottoming it out. If you only get a small amount of motion, there will be errors introduced into your measurement, so it’s best to avoid this. 

After that, just measure the range of motion of the bike and make a simple file you can import. If you are using generic soft tail, you just need 1 measurement.

Note: when using this method to measure your bike, you need to ignore the shock data in the app. In this case, what you are looking at is the sensor data, not the shock. 

Check out what these engineering students achieved using one of our systems. An everyday rider was able to take a big chunk of time out of their local downhill trail.

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We are pleased to announce our new free app for Android devices called Data Logger. With this new app suspension pros can easily gather data from their customers using any device running iOS or Android. The data logger records suspension data from the bike and sends the data to our Coach app for analysis. See this video for a quick introduction to the MotionIQ Coach Edition.

 

 

Introduction

Today we are rolling out a new feature for MotionIQ called Data Logger Link. You may find this new feature useful if:

• You want to help a family member or friend with their suspension setup, but you don’t want them to ride the bike with your iPhone. 
• You want to take your Android phone with you on the bike and you also have access to an iPad or iPhone for analyzing the results

We provide a very simple companion app called Data Logger which you can run on any iOS or Android device. This app is very lightweight and designed for the sole purpose of making recordings on your bike. The recordings are sent to the cloud where you can access them with your iOS device for analysis. 

Getting Started

All users of MotionIQ can use the Data Logger Link and there is no need to upgrade your subscription.

If you already know how to setup your bike with MotionIQ then you should have no problem using the Data Logger Link. If you havn’t setup a bike before you can check out one of our YouTube videos or download the instruction manual. 

To give you an idea of how this works without getting down into the details, here are the basic steps to follow:

1. Configure your bike settings
2. Send an invitation email to your 2nd device
3. Install the Data Logger app and bike settings
4. Connect your Tracer devices
5. Start making recordings
6. Review those recordings on your iOS device

Hope that makes sense. Now let’s repeat those steps with more details: 

1. Open MotionIQ and look for Data Logger Link on the About page. Tap on the icon and tap on [Configure]
2. Think about the bike your friend is going to use. Configure the bike model and the settings for that bike. You can always change these later if needed.
3. Click on the [Send Invitation] button at the bottom. This will send an email containing all the information needed to get the bike setup. 
4. Receive the email on your 2nd device. The email will contain a link to download the Data Logger app to your 2nd device. Proceed to the next step when you have the Data Logger installed.
5. Tap on the email attachment and forward the attachment to the Data Logger app
6. The Data Logger app will open and send you straight into the setup screen. Connect your Tracer device(s) now and calibrate
7. The app will take you to the main screen when you finish calibration. 
1. Tap on the chart to view live data from your Tracers
2. Optionally you can record your sag by tapping [Set Sag] 
3. Tap [Record] to start a new recording and tap stop when finished. Recordings will be sent up to the cloud immediately if you have a good network connection, otherwise they will be queued up and sent later.
8. Return to your iOS device and go over to your Results screen. This will refresh the display and download all recordings you made on the 2nd device. To refresh again just select some other screen (i.e. About) and return to the Results screen.
9. The recordings from your 2nd device will have a name that matches the name of the 2nd device. Scroll down to find them or search for them by name.

Hope that makes sense but if you have any questions don’t hesitate to shoot us an email or contact us through the website chat feature. 

support@motioninstruments.com

 

By now, anyone who’s into downhill racing knows that Greg Minnaar is the winningest racer of all time, owning the most World Cup wins and podium finishes. His performance and fourth World Championship at Val di Sole this year was a great reminder of the success he’s had, further solidifying his G.O.A.T. status. But he’ll be the first to tell you that it takes a great team for everything to come together. 

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