Unusual ABS activation on 2020 R1250R

[coachz]

So I bought this bike new in oct. of 2020 and it's by far the favorite of my bikes. One odd thing though is at light front break pressure even on smooth dry ground I get ABS pulsing. It's annoying as hell and unsettles the bike a little. Thought I was nuts at first as I never see an abs triangle light up on the dash when it's happening until I looked through my rides on the connected ride app and saw all the ABS hits.

I've tried different tires, checking tire pressures, bleeding brakes, bleeding abs pump, new rotors and pads, there is no evidence of damage to the abs sensors or rings. Dealer has flashed the software a fw times and its till happening. Bike has now been in the shop for months and I'm getting frustrated. Anyone else seen this behavior on their wet heads???

Pic below of a track day and the insane amount of ABS, this was also in dynamic pro with traction etc set to minimums as I was on the track. On the main straight Yeah I'm braking from 130 to about 60 so yeah sure I get the abs but the rest of the track is not that fast nor that hard braking.

Second pic is just a tame ride around town and still lots of abs. no matter how subtle I am on the brake lever its still happening.

 

[rangerreece]

I have not experienced this on two different wet heads and 100,000 miles. I suspect you may need to take this one to the dealership and have them run a diagnostic on the brakes.

I did not know the Motorrad app recorded ABS activation, learned something new.

 

[coachz]

Yeah it's been at the dealer for three months now...... Not sure how best to proceed.

I've had a 1200R, 1200RT, 1250RT in addition to this bike and NONE have exhibited this behavior except for the 1250R

 

[akbeemer]

I would start asking to speak to a BMW rep above the dealership. If the dealership hasn’t been able to diagnose the problem, then they are either incompetent or haven’t gotten around to working on it. The dealership will have a BMW rep that the interface with on warranty and other service issues. Play nice, but ask to speak with that person and don’t take no for an answer.

 

[windsailor97]

I am surprised the dealer can't sort that out.

What did you change just BEFORE this started happening? Could it be something as simple as a loose speed sensor or sensor spacing?

Good luck!

 

[coachz]

Thanks for the replies, bike has done this from day one so don’t think it’s anything done to or changed on the bike.

I’m close to elevating this as it has just been way too long now.

 

[rangerreece]

I am surprised the dealer can't sort that out.

What did you change just BEFORE this started happening? Could it be something as simple as a loose speed sensor or sensor spacing?

Good luck!

Good point. Speed sensor and speed sensor ring placement are critical. The micro-latitude of clearance spec on that could cause malfunctions even if it was off slightly… from the factory.

Kevin is right though, it’s time to elevate this, based on your app and comparing it to my app there is definitely a problem, and your dealership needs to take it seriously.

I studied my app last night and I have to either deliberately activate the ABS, which I do occasionally, or I can “remember” what caused it to trip because the conditions warranted it.

 

[coachz]

So the dealer has completed what BMW has told them to and the claim is everything is normal.

Who do I call now?

 

[Geekmaster]

So the dealer has completed what BMW has told them to and the claim is everything is normal.

Who do I call now?

You can try to get hold of the BMW regional manager, and if that doesn't work, then you may want to check with your state's Attorney General and the lemon laws.

 

[skibumwi]

It might be related to the sensor ring on the front wheel being damaged. I had that happen to me and it caused a lot of issues.

Ski

 

[rangerreece]

So the dealer has completed what BMW has told them to and the claim is everything is normal.

Who do I call now?

Regardless of the distance involved… I have actually had luck, simply going to another dealership. Talking to a whole new staff and having a tech at a different experience level can be useful.

 

[88bmwjeff]

You’re dealing with I consider to be one of the most frustrating situations in vehicle ownership and maintenance—an intermittent problem. These can be very difficult to find and costly if you’re paying someone to locate the issue. DAMHIK In my experience, these have ended up being a part that is working, but not 100%. As such, they appear to be operating properly when diagnostics are run. I’m with those who think the issue is with the speed sensor and/or ring.

My suggestion to prove that things are not working as they should would be to find a relatively short loop near the dealer that would cause a lot of unusual ABS activation. Then have the service manager, technician or someone dealership personnel ride a demo bike on the same loop capturing the same data as you do on your bike. After one loop, switch bikes and do the loop over. The ABS activation should be similar on both bikes. If not, then there’s an issue.

If you’re willing to gamble a bit, you could throw a bit more money at the problem. You’ve tried new tires, rotors, pads, etc., but it doesn’t seem like you’ve tried replacing the sensor and/or ring. However, I’d be almost done throwing money at the problem, if I were in your shoes. Negotiate with the service manager to replace the sensor and/or ring and if it solves the problem, they write it up as a warranty issue. If not, then you’ve eliminated another possible cause, but you will be out ±$300 (according to online parts fiche) plus labor for a new sensor ring and sensor (front wheel only). On a side note, the parts fiche show only a ring and sensor for the front wheel. I do not know how the rear wheel speed is monitored by the bike. Keep in mind, I’m no expert here, just throwing out a few suggestions.

 

[crows123]

Looking at your mapping of Lime Rock I feel that you have a sensing problem with the ACC. Even though you are not braking physicaly your sensor is relating this to it due to the rapid deceleration of the bike and picking upon on objects in its path or uneven surfaces. I have found this in my Toyota Tundra at times, and it has active cruise control also ,it's very annoying at times. So I agree with Kevin in that it should go back to the dealer to be replaced for new. Even though these systems work fine 99 % of the time they can't always deal with the forces of nature excerpted on them.