Author Topic: 1992 K75 driveshaft and final drive, fits K100 (higher revs)óDOA/NLA  (Read 2304 times)

Offline mibh

  • Motobrick Curious
  • Posts: 21
  • 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

  • Redline 7000
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  • Posts: 7440
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.
https://tinyurl.com/RillRider

Offline mibh

  • Motobrick Curious
  • Posts: 21
  • 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

  • ^ SuperNatural Motobricker
  • Posts: 497
  • NEEDS MORE CHROME
Rotate FD 90į clockwise from picture
Gear Ratio is stamped on flat top, closest to the swingarm mating surface
  • NYC NY
  • 1991 K100RS 1993 K75S ABS
5 BOROUGHS SISYPHEAN SOCIETY  MAINTAINING THE OBSESSION

Offline Laitch

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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.
https://tinyurl.com/RillRider

Offline mibh

  • Motobrick Curious
  • Posts: 21
  • 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

  • Redline 7000
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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.
https://tinyurl.com/RillRider

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: 21
  • 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
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  • 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

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  • Posts: 21
  • 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
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  • Posts: 7048
  • 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

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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)

Offline Past-my-Prime

  • ^ Proficient Motobricker
  • Posts: 148
Re: second try: 1992 K75 driveshaft and final drive, fits K100 (higher revs)
« Reply #13 on: October 17, 2019, 11:04:57 PM »
Glad to see that these come up occasionally; sorry I missed this one.
  • North Shore of Lake Superior
  • 1989 K75 RT, 2006 (I think) F650 Dakar)

Offline mibh

  • Motobrick Curious
  • Posts: 21
  • BMW rider since 1984
Re: second try: 1992 K75 driveshaft and final drive, fits K100 (higher revs)
« Reply #14 on: October 20, 2019, 08:51:07 PM »
to finish the story, you missed nothing. i packed it badly and the driveshaft was lost in transit. the buyer rejected the diff itself due to bearing noise. i refunded his costs and asked him to dispose of it locally.
  • Skanderborg, DK; California, US; London, UK
  • R100 '81, '84, K100RS '85 (US), K100RS '85 (DK), K100RS '84 (UK)

Offline Ray Charles

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Re: second try: 1992 K75 driveshaft and final drive, fits K100 (higher revs)
« Reply #15 on: October 24, 2019, 08:43:00 AM »
Glad to see that these come up occasionally; sorry I missed this one.

You might be past your prime but you'll never be this young again.  Keep ridin' and keepin' your inner kid alive.  :-) Ray
  • StevensPoint Wisconsin USA
  • 1992 K75RT

Offline Past-my-Prime

  • ^ Proficient Motobricker
  • Posts: 148
Re: second try: 1992 K75 driveshaft and final drive, fits K100 (higher revs)
« Reply #16 on: October 26, 2019, 10:10:35 AM »
You might be past your prime but you'll never be this young again.  Keep ridin' and keepin' your inner kid alive.  :-) Ray

LOL I'd be riding today if I had a new driveshaft and pinion gear (or complete FD).
  • North Shore of Lake Superior
  • 1989 K75 RT, 2006 (I think) F650 Dakar)

Offline Northern Pike

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Re: 1992 K75 driveshaft and final drive, fits K100 (higher revs)óDOA/NLA
« Reply #17 on: January 11, 2020, 09:50:36 AM »
Hey Past-my-Prime,

You and me both. I'm practically a neighbour of yours, here in southern Ontario, with the same problem.
  • Canada
  • 1985 K100 RS

Offline Past-my-Prime

  • ^ Proficient Motobricker
  • Posts: 148
Re: 1992 K75 driveshaft and final drive, fits K100 (higher revs)óDOA/NLA
« Reply #18 on: January 11, 2020, 10:02:06 AM »
Hey Past-my-Prime,

You and me both. I'm practically a neighbour of yours, here in southern Ontario, with the same problem.

Well I have a line on a replacement ds/fd. And a second possibility has come up. If that pans out, I'll let you know!!

Right now what I'd like is a warm place to work on my bike. And a lift. And some more mechanical skills. And a few more tools.

Meanwhile it's -20 outside and we have deep snow so I'm going somewhere warm for a few weeks.
  • North Shore of Lake Superior
  • 1989 K75 RT, 2006 (I think) F650 Dakar)

Offline Northern Pike

  • Motobrick Curious
  • Posts: 12
Re: 1992 K75 driveshaft and final drive, fits K100 (higher revs)óDOA/NLA
« Reply #19 on: January 13, 2020, 09:25:40 PM »
Thanks!

Good idea. Have a nice trip! I'll be here trying to stay warm.
  • Canada
  • 1985 K100 RS

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