Author Topic: second try: 1992 K75 driveshaft and final drive, fits K100 (higher revs)  (Read 310 times)

Offline mibh

  • Motobrick Curious
  • Posts: 20
  • BMW rider since 1984
i did not know how to include pictures before, so the first edition of this topic was (appropriately!) blocked by the moderator. my apologies to all.

i stripped the splines out of my 1985 K100RS driveshaft a few weeks ago, and pulled the driveshaft and final drive off a 1992 K75 hangar queen to get myself back on the road. afterward i replaced the driveshaft and went back to the K100RS final drive, because the K75 final drive ratio was a bit too low -- my RPM's were about 10% higher at highway speed. this meant great low-end torque but more engine noise on straight roads. if not for all the straight roads in between the twisties, i'd've kept this K75 drive. however, i want the K100RS to remain stock.

note that the final drive and driveshaft are a matched set; the number of splines on the interface is different for the K75 vs. K100RS vs. K100LT. i'm selling a matched known-good final drive and driveshaft from a 1992 K75, which i just road-tested to las vegas and back in my K100RS.

$250 + shipping. i'll make a note here if it's sold.

  • Skanderborg, DK; California, US; London, UK
  • R100 '81, '84, K100RS '85 (US), K100RS '85 (DK), K100RS '84 (UK)

Offline Laitch

  • ^ Quintessential Motobricker
  • Posts: 6916
What is the gear ratio of that drive? You'll find it stamped into a flat spot on the rear of the drive housing.
  • 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.
http://www.motobrick.com/index.php/topic,296.msg53303.html#msg53303

Offline mibh

  • Motobrick Curious
  • Posts: 20
  • BMW rider since 1984
your guess is as good as mine, from what's stamped (see picture). but it's 3.2:1 or so, which sounds like 32/10, which was factory for this year.
  • Skanderborg, DK; California, US; London, UK
  • R100 '81, '84, K100RS '85 (US), K100RS '85 (DK), K100RS '84 (UK)

Offline volador

  • ^ Proficient Motobricker
  • Posts: 161
  • NEEDS MORE CHROME
Rotate FD 90 clockwise from picture
Gear Ratio is stamped on flat top, closest to the swingarm mating surface
  • NYC
  • 1991 K100RS 1993 K75S ABS
5 BOROUGHS SISYPHEAN SOCIETY "When Life Throws You A Curve... Lean Into It"

Offline Laitch

  • ^ Quintessential Motobricker
  • Posts: 6916
Here's the stamp location on my moto's rear drive, as correctly indicated by volador.
  • 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.
http://www.motobrick.com/index.php/topic,296.msg53303.html#msg53303

Offline mibh

  • Motobrick Curious
  • Posts: 20
  • BMW rider since 1984
thanks, it was hiding under some road grime. it's 32/10 as measured and as was factory spec for the bike it came from.

  • Skanderborg, DK; California, US; London, UK
  • R100 '81, '84, K100RS '85 (US), K100RS '85 (DK), K100RS '84 (UK)

Offline Laitch

  • ^ Quintessential Motobricker
  • Posts: 6916
So much swapping goes on among these motos, it's good to have verification whenever possible in reference to parts.
  • 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.
http://www.motobrick.com/index.php/topic,296.msg53303.html#msg53303

Offline Feo

  • Motobrick Curious
  • Posts: 18
Sent you a PM about shipping.
  • Central Illinois
1991 K75RT
1990 K75RT
1987 K100RS Hack
(Among others)
Agree Agree x 1 View List

Offline mibh

  • Motobrick Curious
  • Posts: 20
  • BMW rider since 1984
was sold, 2019-08-21.
  • Skanderborg, DK; California, US; London, UK
  • R100 '81, '84, K100RS '85 (US), K100RS '85 (DK), K100RS '84 (UK)

Offline johnny

  • TrailBrakingThrottleWhacker
  • ^ Quintessential Motobricker
  • Posts: 6758
  • Whacking...n...Chopping Sliding...n...High Siding
greetings...

how much and to who who who...

j o
  • :johnny i parks my 96 eleven hundert rs motobrick in dodge county cheezconsin  :johnny

Offline mibh

  • Motobrick Curious
  • Posts: 20
  • BMW rider since 1984
Re: second try: 1992 K75 driveshaft and final drive, fits K100 (higher revs)
« Reply #10 on: August 22, 2019, 04:09:42 PM »
greetings...

how much and to who who who...

j o

the final sale was reported one reply above yours.

the asking price was reported in the base note.
  • Skanderborg, DK; California, US; London, UK
  • R100 '81, '84, K100RS '85 (US), K100RS '85 (DK), K100RS '84 (UK)

Offline johnny

  • TrailBrakingThrottleWhacker
  • ^ Quintessential Motobricker
  • Posts: 6758
  • Whacking...n...Chopping Sliding...n...High Siding
Re: second try: 1992 K75 driveshaft and final drive, fits K100 (higher revs)
« Reply #11 on: August 22, 2019, 04:58:56 PM »
greetings...

so it was $250 + shipping and was sold to feo... is that right...

j o
  • :johnny i parks my 96 eleven hundert rs motobrick in dodge county cheezconsin  :johnny

Offline Feo

  • Motobrick Curious
  • Posts: 18
Re: second try: 1992 K75 driveshaft and final drive, fits K100 (higher revs)
« Reply #12 on: August 22, 2019, 05:07:09 PM »
Yep, I need to give a 32/10 a try on the sidecar rig. Might make 3rd and 4th more flexible.

Wasn't planning on much over 70 mph anyway.
  • Central Illinois
1991 K75RT
1990 K75RT
1987 K100RS Hack
(Among others)

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