Author Topic: Disc "float"  (Read 320 times)

Offline BlitzenGruv

  • ^ Proficient Motobricker
  • Posts: 196
  • My first BMW. Been riding old British forever..
Disc "float"
« on: July 11, 2019, 08:22:02 PM »
This is my first experience with 'floating' discs. Just seems like they feel loose. How do I know?
I can't find any spec in the manual, much less how to measure 'float.'

OK, I read the post on replacing the buffers. Still no info on how much slop is acceptable. The clock on mine says 36K miles. I guess they're all right.
  • Crossville, TN
  • '92 K100rs, 16v, '71 BSA Lightning, '72 Triumph Bonneville, '72 Triumph Trident
You say I'm schizophrenic, but I don't believe we are.

Online Laitch

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  • Posts: 7016
Re: Disc "float"
« Reply #1 on: July 12, 2019, 01:59:05 AM »
Still no info on how much slop is acceptable. The clock on mine says 36K miles. I guess they're all right.
Axial (push/pull) play is acceptable; radial (rotational) play isn't desirable but if the brakes are stopping well under load, ride on. If bothered by noise, earplugs—as usual—are the solution.
  • Along the Ridley in Vermont.
  • 1995 K75 72,000 miles
I wept because I had no radials until I met a man who had no splines.
https://tinyurl.com/RillRider

Offline BlitzenGruv

  • ^ Proficient Motobricker
  • Posts: 196
  • My first BMW. Been riding old British forever..
Re: Disc "float"
« Reply #2 on: July 13, 2019, 12:17:26 AM »
Thanks,
Not too much play, as I said it's just new to me. Everything else I have has fixed rotors.
Brakes stop well at speed, they just feel a little weird at slow speeds. Maybe that's the ABS?
Still quiet, though.
  • Crossville, TN
  • '92 K100rs, 16v, '71 BSA Lightning, '72 Triumph Bonneville, '72 Triumph Trident
You say I'm schizophrenic, but I don't believe we are.

Online Laitch

  • Redline 7000
  • Forum Moderator
  • ^ Quintessential Motobricker
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Re: Disc "float"
« Reply #3 on: July 13, 2019, 05:56:48 AM »
. . . they just feel a little weird at slow speeds. Maybe that's the ABS?
At low speed hard braking you might be feeling them pulsate. At high speed hard braking you don't feel that because you're preoccupied by your watching your life flash before you.
  • Along the Ridley in Vermont.
  • 1995 K75 72,000 miles
I wept because I had no radials until I met a man who had no splines.
https://tinyurl.com/RillRider

Offline alabrew

  • ^ Proficient Motobricker
  • Posts: 137
Re: Disc "float"
« Reply #4 on: July 13, 2019, 01:04:22 PM »
When I got my 4v, the rotors were pretty clanky and had a lot of float. Several bobbins were also mangled. I replaced the rotor bobbins, very simple to do, and all is much better.
  • Alabama
  • 1985 K100, 1991 K100RS
Also:
2005 K1200LT
1979 R65
200,000 miles on BMW motorcycles

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