Fault - Braking or Engine Braking

[swalker2]

Hi all, looking for info from anyone else who has had this issue.

I have had the same fault now approx 3-4 times in the last 12 months of owning the bike from new, personally I think it's dangerous but without BMW finding it I am not sure how I will get it resolved.

This is what happens (Note the bike can be cold or hot) I will be riding then suddenly it will be like riding with the brakes on. The last time this happened it was 15 or so seconds after pulling my front brake, not directly after so this is not a seized caliper etc.  I am not leaving my foot on the rear brake - further to other posts that brake is terrible and very rarely used for that reason. Unfortunately when this has happened I have been unable to let it come to a stop so I can check the temps on the brake disks to rule out brake binding. BMW have checked that previously and said it was fine.

The last time this happened I pulled my clutch and rev'd it hard, I may have changed down gears, I can't remember. but when you are pulling up a dual carrigeway and its wanting to stop it's a bit worrying

Its due a 6K service where I will raise it again.

[brucedimon]

What a strange problem. 

Is there any error code on the TFT?

Do you have a GS-911 to see if there are any codes in the computer?

Is it possible that this is a loss of engine power in spite of the engine revving?

Good luck. This is crazy.

[rcb78]

I'm curious, if you let of the throttle during the event did the bike slow down more than normal?  Did you pull in the clutch to eliminate the engine/transmission?  It would be easier to identify if you knew whether it was related to loss of power or increase in drag.

[swalker2]

Sorry for the delay in coming back.

No errors on the TFT and I don't have any tools to "decode" the issue should it be reporting one, that said BMW have checked it and said they couldn't find any issues.

Good point on the Clutch question, I am pretty sure when I pull the cluth in the issue is resolved, let it go and its back which rules out brakes in my mind.

In terms of how bad this is, It feels like the front brake is on 30% whilst riding, I come off the throttle and the slow down is significant. It feels like I am towing something. I am sure its the engine.

I have the mode set to Dynamic, I don't ride beyond its limits, nothing like. Annoyingly 4 times in 12 months is probably no enough unless I am lucky to get it fixed.

[swalker2]

I had it again this week but was able to stop. I did forget to pull the clutch but it ground to a halt very quick, I got off and touched the brake discs, one cold one red hot….looks like a calliper issue. Service this coming Friday and they will look at this.

[Daimac]

Glad you’ve narrowed it down to the calliper!

[LP17]

Well Done. Hope you have a quick cure.  

[swalker2]

BMW reckon it was dirt in the Caliper. The roads are bad I agree but I have used backs through the thick of winter before without this do remains to be seen if this has sorted it, what it has pushed me to do is service my own brakes.