Brembo Caliper Mount Sleeve

[marcmax]

Can anyone tell me why there are so many different sizes of the sleeve that the Brembo caliper mounting bolts go through to mount the caliper? After one of my calipers failed I swapped it with a caliper from my spare parts bike. Ever since the brakes on that side dragged to the point of stopping the front wheel rotating freely. Fortunately I have been busy and only rode once about 3-4 miles.

When I started checking and actually placed the two calipers side by side I found that the shoulder on the sleeves was different by almost double the thickness. I swapped them between calipers and all is back to normal I just don't understand why.

[montmil]

The Brembo caliper is used on a variety of bike models so perhaps the bolt sleeve length is dictated by the fork lower design? Other than that guess, it's a good thing to have replacements in a size you might need.

[georgesgiralt]

Well, if you calculate the stack of tolerances on the wheel bearing placement inside the hub, the thickness of the lip seal sleeves, the position of the stop on the wheel axe, then the thickness of the disk brake bowls you'll see that you may have to adapt the position of the calliper in order to have the disc brake quite centre the calliper’s opening...
And add to this that BMW did not want a special casting from Brembo when they decided to have the second brake fitted, in order to reduce costs...
What do you think ?

[Bob_Roller]

It's not just the Brembo calipers, if you have dual ATE calipers, the right caliper has the same sleeve / bushing as the brembo set-up .

The different thickness of the flange area of the bushing, is to get the caliper centered on the disc .

[marcmax]

Maybe I am taking a simplistic view of things. Both of my R65's are LS with a factory wheel, factory disks, factory Brembo calipers and are setup identical. There are no special bearings or spacers, no difference in the disk carrier mountings that I can see. Yet when I took the right side caliper off one bike and installed it on the right side of the second bike the thickness of the sleeves was off to the point of being unrideable. Swapped the sleeves and everything works.

My thinking was same assembly, same parts, same tolerances it should be a straight across swap. Am I missing something here or am I chasing a gremlin that doesn't exist. I don't want the difference to be because something is f'd up.

[Bob_Roller]

I've got three R65's and that sleeve / bushing flange is a  different  tickness on all of the right hand calipers .

Don't know why !!!!!!

[Luca]

My LS has two flanged aluminium bushings on the right hand caliper only.  ATE calipers.

As far as why the swap worked... have you checked that the wheel is installed in the proper direction (or was the tire installed in the wrong direction)?  Can't recall off hand, but the brake rotor bolts stick out one side and the nuts are on the other.

Are the axle spacers the same in both wheels?