[Barab42]

2020 R1250GS, 12200 miles, all paved. The bike pulses when coming to a stop slowly. I’ve seen other threads discussing this issue, but on older R1200GS’s. i first noticed the issue at the 6k service, when I told the dealer about it. He just said let them know how it is at the 12k service.

Bike is in the shop now for the pulsing and the 12k service and to check for caliper leaks. Service mgr informed me today that BMW has instructed them to replace the Hayes calipers with the Brembo’s. He also said the rotor(s) might be warped, but couldn’t say for sure what would fix the pulsing issue. Would replacing the calipers possibly fix the pulsing issue?

 

[60Aviator]

Yes the rotors (usually only one) could be the problem but I would leave that as the last thing. I would wait till they finish the calipers first, clean rotors, and then reseat/bed the brake pads. Since they have the bike for calipers isn't it still under warranty? If not then a good Service manger could figure out bad calipers warped rotors if they are the problem.

 

[Barab42]

Still under warranty. I’m not sure what the service mgr knows. My impression is that he plays dumb to avoid uncomfortable conversations.

 

[bosnjo]

Rotors for sure. If it's been like that from day one, it means one of the rotors came out of the factory warped. If it started later, one or two rotors warped due to overheat. Now, why overheat happened is the other question.
Pullig off with front disk lock on the disk (happened to all of us) can warp the rotor badly too.

 

[Barab42]

Rotors for sure. If it's been like that from day one, it means one of the rotors came out of the factory warped. If it started later, one or two rotors warped due to overheat. Now, why overheat happened is the other question.
Pullig off with front disk lock on the disk (happened to all of us) can warp the rotor badly too.

I didn’t notice any pulsing until maybe 3000 miles. If by “disk lock” you mean the Hill Hold feature, I don’t use it much.

Has anyone had their front rotors replaced by a dealer, and were they covered by the OEM warranty?

 

[bosnjo]

If by “disk lock” you mean the Hill Hold feature, I don’t use it much.

No, I mean disk lock, the lock you put on your disk to lock the bike when parked. I use it every day and only once I forgot to take it off but fortunately to take the bike out of the parking space I had to reverse it, so when disk lock hit the fork it was not with force. Only little scratch on plastic protecting the fork. But, there are a lot of riders that forgot to remove disk lock and pull off forward with force making a lot of damage on fork and warping the disk.

 

[Barab42]

For the record, I do not use that kind of security lock. I’m relieved because I thought you were saying that using the Hill Hold feature could cause warping.

 

[Barab42]

Trying to plan for the worst, what OEM or non-OEM rotors would you suggest for the R1250GS?

The linked brake system means that using the rear brake activates one or both of the front calipers?

 

[bosnjo]

BMW uses good quality disks so I'd go with OEM ones. Before replacing them, check if front pads are dragging on the disk. They can cause overheet of the disk and warp it. There is hidden adjustment on the brake lever to control pads dragging.
The linked brake system means that using front brake (lever) will activate both front and rear brakes and using rear brake (pedal) will activate only rear brakes.

 

[lgm118icbm]

I'm having the same issue on my '19 GSA since ~6k miles and she has 15k now. Runout and disc thickness are within spec and both me and the dealer have cleaned / scuffed them several times now to no avail. I suspect though runout is within spec (.11mm measured, .15mm is spec), it is sufficient to be felt and cause handling problems at low speed.

 

[Barab42]

Picked up bike today. Only rode 10 miles, but S.F.S.G. To be cont’d.

 

[Barab42]

.

 

[bosnjo]

The question remains: why the rotors got warped? Was the source of the problem solved or new rotors will get warped soon too?
It happened to me once in my car and needed new rotors just after one month after replacing them. The problem was in one of the calipers where one of the pistons wasn't returning properly into the cylinder so the rotor was overheating and got warped quickly. So, new rotors again and fully serviced front calipers with new seals and problem has never returned again.

 

[Barab42]

Picked up bike today. Only rode 10 miles, but S.F.S.G. To be cont’d.

The question remains: why the rotors got warped? Was the source of the problem solved or new rotors will get warped soon too?
It happened to me once in my car and needed new rotors just after one month after replacing them. The problem was in one of the calipers where one of the pistons wasn't returning properly into the cylinder so the rotor was overheating and got warped quickly. So, new rotors again and fully serviced front calipers with new seals and problem has never returned again.

Didn't notice any pulsing for the 10 miles that I rode it. Dealer said the runout is well within spec. FWIW, I think the Brembo's have a different feel, not better or worse, just different. Smoother maybe?