Results 1 to 6 of 6

Thread: BMW Dry Clutch Configuration

  1. #1
    Registered User
    Join Date
    Aug 2012
    Location
    Farmington Hills, MI
    Posts
    37

    BMW Dry Clutch Configuration

    Just curious - any ideas why the BMW dry motorcycle clutch is configured differently than a typical auto clutch? Below are illustrations of oilhead clutch and typical auto clutch.

    BMW Clutch resized.jpg

    Auto clutch Apr20.JPG
    Ken S
    03 R1150RT

  2. #2
    Quote Originally Posted by nosvamos View Post
    Just curious - any ideas why the BMW dry motorcycle clutch is configured differently than a typical auto clutch? Below are illustrations of oilhead clutch and typical auto clutch.

    BMW Clutch resized.jpg

    Auto clutch Apr20.JPG
    Well, I think the answer is simple. In most cars the pedal pulls the pressure plate away from the disk and on BMW motorcycles t pushes the pressure plate spring away from the disk.
    Paul Glaves - "Big Bend", Texas U.S.A
    "The greatest challenge to any thinker is stating the problem in a way that will allow a solution." - Bertrand Russell
    http://web.bigbend.net/~glaves/

  3. #3
    Doug D
    Join Date
    Jan 2017
    Location
    Grandville Mi
    Posts
    27
    It could be that the design was to ensure that the clutch disc would not engage to the flywheel. Advantage of this is when the clutch is replaced the flywheel would not have to machined flat due to wear. On the newer models the flywheel is now a piece of stamped steel called the clutch carrier. The flywheel on my /5 is solid steel like what is in a car or truck. Probably cost less to make a clutch carrier and lighter too.

  4. #4
    Registered User
    Join Date
    Jan 2005
    Location
    Sioux City, Iowa
    Posts
    92

    Dry clutch design

    I think it was just a packaging decision. By moving the diaphragm spring ahead of the clutch they could eliminate the normal release bearing and actuating arm. With the clutch release rod passing thru the input shaft it shorten the trans length considerably. With the small diameter rod it could ride directly on the spring without causing much wear. This allowed for the normal large throw out bearing to be much smaller and at the rear of the trans where it is easily serviced. Actually quire a brilliant packaging solution.
    Chuck Swenson
    MOA # 9162
    2010 R1200RT, 2003 F650cs (BMW #12 & 13)

  5. #5
    Registered User pappy35's Avatar
    Join Date
    Nov 2017
    Location
    Collierville, TN
    Posts
    577
    I thought there was no throw out bearing on the clutch itself? The actuator rod applies no pressure to the spring plate when the clutch is disengaged (I get confused with this wording sometimes, I mean in-gear and driving the rear wheel). When engaged the slave cylinder has a bearing in it that the rod spins on. Is this correct?
    '13 R1200RT 90th Anniversary Edition

  6. #6
    Registered User
    Join Date
    Jan 2005
    Location
    Sioux City, Iowa
    Posts
    92
    Right, no throw out bearing in the clutch. It on the back end of the pushrod. In a housing on the trans rear cover on all cable operated clutches and in the slave cylinder of the hydraulic operated ones.
    Chuck Swenson
    MOA # 9162
    2010 R1200RT, 2003 F650cs (BMW #12 & 13)

Similar Threads

  1. Replies: 5
    Last Post: 05-27-2017, 04:20 PM
  2. New liter go fast rocket configuration
    By Omega Man in forum Motorrad
    Replies: 4
    Last Post: 04-29-2017, 06:57 PM
  3. Airhead clutch configuration swap
    By jforgo in forum Airheads
    Replies: 7
    Last Post: 01-14-2014, 05:01 AM
  4. F650 GS Handle Bar Configuration
    By hoss01 in forum F-Twins
    Replies: 2
    Last Post: 09-15-2013, 12:20 AM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •