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In the last 4 weeks I have done 3 track days. I notice at this last track day my front suspension just was not flowing with the bumps. This track is really bumpy with alot of concrete to asphalt transitions. ECR I am talking about for those in Texas.

I rarely look at my suspension histograms, but with DDC being a hot topic in this post http://www.s1000rrforum.com/forum/bmw-s1000rr-general-discussion/183185-datalogger-instruction-resources-2.html and it referencing this page Histograms and Suspension Velocity Analysis

I decide to look at my histograms. I only had one bar in the graph. I thought is my 2D front sensor broke? Sure enough I pulled another graph out of another track and there was the many bars showing compression and rebound activity. See graphs I posted in case you have the HP DataLogger and it is in " Functions " "Histogram" "Suspension Speed Front"

These graphs show the activity in the front suspension, or in my case, the lack there of since the sensor appears to be dead.

I removed the 2D sensor yesterday and ohm'ed it out and sure enough, it is open. I guess it wears out in about 8K hard miles. I already had a spare sitting on the shelf as backup, and sure enough, I ohm checked it, and perfect movement of the ohms as the slider is moved in and out. I put the new one on there and tried it out today for 150 miles, and back to much better feel in the front suspension. Wow, that 2D sensor causes some serious bad information to the suspension ECU, which passes that on to the front fork with DDC.

If you have a 2D front sensor, and dont have HP Datalogger to read the working or not working of the 2D sensor, you might want to remove it and ohm it out. If it is open, you will not get any reading on the meter.
 

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Thanks for sharing! If it goes out after 8k, I'm not getting it. I do long rides, some bumpy roads.

Is your RR track only?
 

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Discussion Starter #3
Not even track only stuff.

4 trips to Arkansas mountains
3 COTA track days
4 MSRC track days
Deals Gap / Dragon
ECR track day

countless runs on what is called Ida Road here in North Texas.

The sensor really makes a big difference in how the bike handles. I knew something was wrong, but just didnt know how to find the cause until I saw that suspension histogram.
 

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Thanks for posting this. I have the 2d sensor on my HP4.

Off topic: Did you get to do your brake pad testing at COTA? And what were the results?

Which Brembo caliper were you using with your underslung rear mount? You didn't like the one included with the mount? :confused:
 

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I did not get to attend the July COTA event. Health issues with my right hand. Today it is better, and I will be at Barber Motorsports with STT Aug 13/14 .. I hope I can do some testing there. I have several types of front brake pads to try on my GP4 calipers. Currently using the Ferrodo brand. Tried the Brembo's from my HP4 M4 calipers, and those did not work too good in Arkansas.

I put the Brembo P2 34 on there now. The pads with it are Brembo but they just dont have much bite on the rotor. I just got some new Ferrodo carbon metallic in today. I still have some air in that rear line unit however and bleeding it often to firm up the petal.

I really dont use the rear brake 98% of the time. I 100% have that rear under slung unit so my rear wheel remove and replace are so much easier. I can do a change in less than 2 minutes if I try hard enough. I wanted the Brembo for looks as it match my GP4 calipers with the NiCad coating. Then I do use the rear brake at one race track with one certain corner that I can slightly back it in on that corner.
 

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My 2D sensor can off the top mount one time!
Luckily I had a tie wrap loosely around the wire so it caught it and no damage.

Presumably if the sensor completely fails as the OP mentions, the 'calibration' routine would fail?
 

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Discussion Starter #8
@Piper

Glad you mentioned that about CALID. It does not FAIL. As you can see in the graph, the suspension ECU sees it is plugged in even in an open condition. I went back to the HP DataLogger measure tables and it is stuck at -10.0mm / -0.39in ... I did the CALID before I removed it and it passed diagnostics.
 

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Especially my brake pads as many as I have tried in the last 1.5 years.

Those are some nice carbon pieces. I think there needs to be a rubber bellow on the slider shaft to protect from the dust issue.
 

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I did take it apart today. Cleaned up the contacts with 2000 grit paper, cleaned the tube out, polished the shaft... reassembled and it works again.

I will change it out with my spare that is on the bike now and just put more miles on this one, save the other for backup again in case I need it at the race track or out of town ride event.
 

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Thanks BMW_388 for starting this tread. I picked up a preowned D2 sensor, and due to your post and other members that contributed to this, I took it apart. It was dirty and needed service badly. What I noticed after installation is that the unit does not align perfectly to the fork tube with the supplied hardware. That causes the shaft to stroke at a slight angle, which as shown in the picture ruins the seal, and allows dust/dirt to pass inside the unit. I'm still working on the best method of protecting it from debris, but if anyone has one installed for a while, it may be worth servicing soon.
 

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What pins did you get the resistance across and what range should I be looking for?
bought a used sensor today and plugged it in but I still have front dmp showing and not front comp and rebound
 

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Discussion Starter #18
Thanks BMW_388 for starting this tread. I picked up a preowned D2 sensor, and due to your post and other members that contributed to this, I took it apart. It was dirty and needed service badly. What I noticed after installation is that the unit does not align perfectly to the fork tube with the supplied hardware. That causes the shaft to stroke at a slight angle, which as shown in the picture ruins the seal, and allows dust/dirt to pass inside the unit. I'm still working on the best method of protecting it from debris, but if anyone has one installed for a while, it may be worth servicing soon.
Those sensors just wear like that. Put a bellows rubber on the shaft to the body and this will help. I see them on ebay and thought about getting one some day and try it.
 

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What pins did you get the resistance across and what range should I be looking for?
bought a used sensor today and plugged it in but I still have front dmp showing and not front comp and rebound
you need to connect the sensor to the bike and back probe the pins for voltage levels. Its a 10K ohm device, but the rail elements might be bad enough that when 5V is applied it is not working correctly.

I have posted this information before back in 2015. It is very hard to find on 2D website.



 

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you need to connect the sensor to the bike and back probe the pins for voltage levels. Its a 10K ohm device, but the rail elements might be bad enough that when 5V is applied it is not working correctly.

I have posted this information before back in 2015. It is very hard to find on 2D website.



The connector on my sensor only has 3 pins


Sent from my iPhone using Tapatalk
 
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