Cush Drive Inserts- service life?

Discussion in 'Parallel Universe' started by johngil, Aug 3, 2009.

  1. johngil

    johngil Reseda, CA

    Joined:
    Jun 28, 2007
    Oddometer:
    3,816
    I've never owned a bike w/ a cush drive setup.
    At 8,000 miles, the rubbers are pretty much toast. They are almost in two pieces.
    Is this normal. Bike is a BMW 800 GS.
    #1
  2. bxr140

    bxr140 Flame Bait

    Joined:
    Jan 25, 2007
    Oddometer:
    1,041
    Location:
    On high
    At 10,6XX miles, one of mine was in two pieces.

    FWIW, I lube them when reinstalling so they can move and compress easier. Not sure if it actually does anything or if its just peace of mind.
    #2
  3. Bayner

    Bayner Long timer

    Joined:
    Mar 27, 2008
    Oddometer:
    2,023
    Location:
    Penticton, BC
    My KTM had an actual spec for the amount you could move the sprocket before the hub moved, but I'll be damned if I can remember what it was... maybe I'll go look if I have the digital manual still.
    #3
  4. Bayner

    Bayner Long timer

    Joined:
    Mar 27, 2008
    Oddometer:
    2,023
    Location:
    Penticton, BC



    Okay, here we go. (Was a 38 tooth rear sprocket IIRC so 6 mm may be acceptable on the 800. I changed mine out when they started to look ratty, which was around 14k kms.)​







    "Checking the shock absorption rubbers in the rear hub *








    LC4 models have a damped rear wheel hub. For this purpose, the engine
    power is conveyed from the rear sprocket via 6 shock absorption rubbers
    to the rear wheel. These 6 absorption rubbers wear with increasing
    operation time, and should be checked for wear whenever the rear wheel is
    dismounted.
    For this purpose, lie the rear wheel on a work bench with the rear sprocket
    upwards, and put the wheel spindle in the hub. Now hold the rear wheel
    firmly and try to turn the rear sprocket. The rear sprocket may not turn
    more than maximum 5 mm (0,2 in) measured on the outside. If the play in
    the chain wheel is larger, all 6 shock absorption rubbers are to be replaced.
    Check the shock absorption rubbers for signs of damage and dirt.



    ! CAUTION !


    IF THE SHOCK ABSORPTION RUBBERS ARE NOT REPLACED IN GOOD TIME, THE REAR

    SPROCKET CARRIER AND THE REAR HUB WILL BE DAMAGED. ALLWAYS REPLACE ALL
    6 ABSORPTION RUBBERS, NEVER SINGLE RUBBERS."
    #4
  5. johngil

    johngil Reseda, CA

    Joined:
    Jun 28, 2007
    Oddometer:
    3,816
    Thanks for posting that.
    Mine need replacing for sure.
    #5
  6. Kawidad

    Kawidad Long timer

    Joined:
    Jul 9, 2005
    Oddometer:
    6,149
    Location:
    Central Coast, Cal
    Wow, that's weird. :yikes The cush drive rubbers should last almost forever, at least they do on most Japanese bikes.......
    #6
  7. lesman

    lesman Live easy, Brake Hard

    Joined:
    Sep 7, 2006
    Oddometer:
    3,585
    Location:
    Baja Okahoma
    V Strom specs are 20,000 miles. Some people say after 2 rear tires. Mine are in very good shape at 16,000 miles. They will be replaced at 18,000 to 20,000 miles. If there is any slop they should be replaced. Slop to death of the rubber I think is pretty quick. This should be a proactive not a reactive service.
    If you worn out a set at 8,000 miles. How many tires did you wear out? If the answer was at least 2 then you should be replacing them more often. I paid I think $42.00 with shipping(it may have been a bit more). I think this is absurd amount of money...sin isn't cheap.





    Les
    #7
  8. johngil

    johngil Reseda, CA

    Joined:
    Jun 28, 2007
    Oddometer:
    3,816
    On my third set of tires.
    #8
  9. nr552

    nr552 Been here awhile

    Joined:
    Jul 7, 2006
    Oddometer:
    301
    Location:
    Sandy Eggo
    44.5k mine on my wee in a little over 3 years, and the cush is still cush on my bike. I do a lot of commuting though... maybe that helps.

    On my DR350->435s I had years ago, it would tear through the cush drive about every 7500 miles due to a lot of off road riding (figure spin and grip of the tire puts a lot of wear on the cush).
    #9
  10. greywolf

    greywolf Unpaved road avoider

    Joined:
    Apr 2, 2006
    Oddometer:
    1,319
    Location:
    Evanston IL
    Silicone spray is a good lube for installing cush rubbers. Silicone grease will stay in place better and possibly improve the wear factor that reduces their size over time. Do not use anything petroleum based. Cheapskates can use inner tube strips or sheet aluminum, depending on the amount of free play, to shim the old rubbers.
    #10
  11. westnash

    westnash Long timer

    Joined:
    May 9, 2004
    Oddometer:
    3,789
    Location:
    Phoenix, AZ
    Aren't these there more for noise reduction than anything else? Many aftermarket sprockets don't have them and it doesn't seem to matter.
    #11
  12. bxr140

    bxr140 Flame Bait

    Joined:
    Jan 25, 2007
    Oddometer:
    1,041
    Location:
    On high
    Its to absorb the impact transmitted back through the chain to the transmission when you get on/off the throttle.
    #12
  13. eakins

    eakins Butler Maps

    Joined:
    May 29, 2002
    Oddometer:
    25,514
    Location:
    Fort Collins, Colorado
    you're thinking of the rubber on oem counter sprockets. this does reduce some chain noise, but i'd guess aftermarket does not use because of cost.

    this thread is about the rubber inserts inside the rear wheel cush drives
    #13
  14. cba191

    cba191 wanna buy a monkey?

    Joined:
    Sep 23, 2004
    Oddometer:
    837
    Location:
    SLC, UT
    my dealer replaced mine at 10,500 miles when the mounted my shinko 705s. the bonus was that they did it at no charge! :clap
    #14
  15. lesman

    lesman Live easy, Brake Hard

    Joined:
    Sep 7, 2006
    Oddometer:
    3,585
    Location:
    Baja Okahoma
    You definitely drive fast.I'm pissed when my rear tire starts looking worn at 6000 miles and needs replacing at 7500-8000 miles. I may ride fast but I don't ride hard.I've been a driveshaft and belt guy for 20 years. I'm still not enamored with chains and cushdrive dampers. After 18 months it only annoys me.
    I enjoy the flexibility of a chain. Modern chains don't break especially with me as a driver.




    Les
    #15
  16. Kawidad

    Kawidad Long timer

    Joined:
    Jul 9, 2005
    Oddometer:
    6,149
    Location:
    Central Coast, Cal

    I spoke too soon in my posting. I just took my DL1K in to get a new back tire mounted at 12k miles and my mechanic told me my rubbers are nearly done. They look good, but they are sloppy and worn.:cry
    #16