Results 1 to 14 of 14

Thread: 91 k75s Fork Lock Question

  1. #1
    JohnWC
    Join Date
    Mar 2010
    Location
    Akron, Ohio
    Posts
    691

    91 k75s Fork Lock Question

    I don't know if anyone has had this quirky problem. I put the key into the fork lock with the forks turned all the way to the right. The lock moves slightly inward, likes it's loose, but then just stops. I can't feel any detent or anything that suggests there is a place for the lock to go into. I swing the fork back and forth, but again, nothing. I don't know how anyone could break a fork lock, but maybe it's possible. I'm using the ignition key that came with it, the old folding style, and I have another flat key. Both go into the lock but won't turn it, or push it it any further. Did someone change the ignition lock and throw away the original key set? Good chance. Is it possible to get the original fork lock key? Any advice? Thanks.

  2. #2
    Registered User GTRider's Avatar
    Join Date
    Apr 2006
    Location
    Nibley, UT USA
    Posts
    1,800
    The fork should lock with the front wheel turned to the left, so give the lock a good soaking with TriFlow or a similar lubricant then try it with the wheel turned left.

    Best,
    DeVern
    DGerber
    1983 R80ST — 1984 R80 G/S-PD — 2004 K1200GT w/Hannigan S/C — 2010 K1300GT — 2018 R1200GS
    BMWMOA#52184, AMA#271542, IBA#138

  3. #3
    3 Red Bricks
    Join Date
    Jan 2007
    Location
    Pleasanton, Ca.
    Posts
    5,045
    Sorry DeVern. It's different on a K75.

    Turn wheel all the way to the right and insert key into fork lock.

    Turn key to the left (counter clockwise) and apply inward pressure. Hold the key in that position with inward pressure.

    Slowly turn steering towards center. When you get about half way towards straight, you will feel the key go in about 3/16". Turn key to the right and remove key.





    LONG MAY YOUR BRICK FLY!

    Ride Safe, Ride Far, Ride Often

    Lee Fulton Forum Moderator
    3 Marakesh Red K75Ss
    Mine, Hers, Spare

  4. #4
    Registered User GTRider's Avatar
    Join Date
    Apr 2006
    Location
    Nibley, UT USA
    Posts
    1,800
    Quote Originally Posted by 98lee View Post
    Sorry DeVern. It's different on a K75.

    Turn wheel all the way to the right and insert key into fork lock.
    I stand corrected; thank you Lee!

    That’s completely opposite from my liter/liter+ brick-k bikes as well as any other motorcycle I’ve ever owned- back in the day the conventional wisdom was that parking with the wheel cranked left added stability and made it tougher for the bike to be accidentally bumped off the sidestand. Unless the sidestand was on the right, of course...


    Best,
    DeVern
    DGerber
    1983 R80ST — 1984 R80 G/S-PD — 2004 K1200GT w/Hannigan S/C — 2010 K1300GT — 2018 R1200GS
    BMWMOA#52184, AMA#271542, IBA#138

  5. #5
    JohnWC
    Join Date
    Mar 2010
    Location
    Akron, Ohio
    Posts
    691
    I tried to get to to move in but no luck. The fork moves smoothly back and forth with no hint of where the detent is. I assume that there is some part of the lock that actually slides in the lock barrel. The lock probably hasn't been used in a long time. Although the part I can see is moving around, maybe the other part is frozen in place. The only thing I can think of is to patiently shoot Kroil onto the lock for a few weeks to see if that helps.

    Would it be okay to gently tap on the face of the lock with a small plastic bar, (without the key in),
    or could that damage the lock?

  6. #6
    3 Red Bricks
    Join Date
    Jan 2007
    Location
    Pleasanton, Ca.
    Posts
    5,045
    Quote Originally Posted by jconway607 View Post
    Would it be okay to gently tap on the face of the lock with a small plastic bar, (without the key in),
    or could that damage the lock?
    John,


    The lock cylinder only moves in when the key is turned all the way to the left AND the slot in the steering shaft is aligned with the lock. Randomly tapping on the lock will likely not have positive results since you can not meet the above requirements with the key out.

    Do you have the bike on the center stand?

    Are you holding the key fully to the left and holding inward pressure on it as you slowly turn the steering from the far right towards the center? Do you feel the lock move inward about 1/8" to 3/16" at about the steerings half way point between full right and straight ahead ?



    LONG MAY YOUR BRICK FLY!

    Ride Safe, Ride Far, Ride Often

    Lee Fulton Forum Moderator
    3 Marakesh Red K75Ss
    Mine, Hers, Spare

  7. #7
    3 Red Bricks
    Join Date
    Jan 2007
    Location
    Pleasanton, Ca.
    Posts
    5,045
    Quote Originally Posted by jconway607 View Post
    Both go into the lock but won't turn it, or push it it any further.
    Are you turning the key to the LEFT? It should turn to the left about 45degrees (1/8 rotation).

    You need to maintain inward pressure on the key. You might not feel the lock cylinder go in when you reach the slot in the steering head, but the steering will hit a stop when the lock cylinder goes into the slot. Keep the steering pressure against the stop while turning the key back to the right. Remove key.




    Last edited by 98lee; 11-28-2020 at 03:31 AM.
    LONG MAY YOUR BRICK FLY!

    Ride Safe, Ride Far, Ride Often

    Lee Fulton Forum Moderator
    3 Marakesh Red K75Ss
    Mine, Hers, Spare

  8. #8
    I gathered from the original post that neither of the bike keys would turn. If that is so then it won't lock. Some penetrating lubricant sprayed in the lock might help. Or maybe neither key actually fits that lock.
    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/

  9. #9
    RK Ryder
    Join Date
    Sep 2005
    Location
    London, Ontario
    Posts
    3,020
    I discovered early in my ownership of my K100 that the fork lock was so difficult to engage that I had a concern that finally locking it might be difficult (impossible?) to unlock. So far, in almost a hundred thousand miles, no one has disappeared with the old K.😊
    Paul F. Ruffell
    Retired and riding my RTs, the '87 K100 & the '98 R1100 !
    Knights of the Roundel #333

    2021 Great Falls MOA Rally Volunteer Chair

  10. #10
    Yes, you CAN break the fork lock. 100 years ago I locked my brand new K100RS with the folding key and could not get it to unlock. Since I didn't want to leave my new bike at a burger joint and walk home (this is well before cell phones) I broke the lock pin by jamming the fork to the right until it gave way. I got it fixed and was told by the tech to NOT use the folding key on the fork lock since it has closer clearance than a flat key. 35 years later and I have never used the fork lock again no matter the key.

    Frank
    '17 R1200RS, '03 R1100S BCR#6/200, '85 K100/1100RS, '16 R1200RS (gone) '11 R1200RT (gone) '05 R1200ST (gone) '99 R1100S (gone) '96 Ducati 900SS/SP (gone) '92 K100RS (gone) 500,000+ BMW miles

  11. #11
    JohnWC
    Join Date
    Mar 2010
    Location
    Akron, Ohio
    Posts
    691
    Quote Originally Posted by PGlaves View Post
    I gathered from the original post that neither of the bike keys would turn. If that is so then it won't lock. Some penetrating lubricant sprayed in the lock might help. Or maybe neither key actually fits that lock.
    True, neither key, (folding or flat) wants to turn the lock. I can see that the lock is loose in the barrel. I am left with the conclusion that Paul is correct; these keys aren't the ones that came with the bike and won't work. The folding one works the ignition, so maybe it was replaced. Is there a way to get the right key for it, using the serial number and BMW's records? I don't see any numbers on the fork or seat lock.

    I'm probably going to follow other's good advice and skip ever using the fork lock. But it would be nice to at least have the correct keys. Another lesson learned (again): never buy a bike that hasn't been well cared for.

  12. #12
    Registered User drneo66's Avatar
    Join Date
    Jun 2009
    Location
    Rochester, MN
    Posts
    764
    Do you existing keys work on the saddle lock?
    Current: 2007 BMW R1200RT, 2013 F800GS
    Former: 1995 BMW K75S, 2009 BMW G650GS
    MOA Member #:150400, IBA#: 37558

  13. #13
    3 Red Bricks
    Join Date
    Jan 2007
    Location
    Pleasanton, Ca.
    Posts
    5,045
    John,

    As DeVern has suggested, try squirting copious amounts of TriFlow, WD40, or Kroil into the key slot. Then run the key in and out many, many times. Then see if it will turn 1/8 of a turn to the left. If not, repeat a few times. You might get lucky and only have stuck pins in the lock.

    The brass drive rivit is what holds the lock in. If you can grip it with some end cutters or side cutters and pull it out (twisting counterclockwise I think and pulling), the lock is rekeyable to your existing ignition key. If you are really careful, you might not trash the rivit and be able to reuse it. Finding the appropriate size rivit to replace it might not be easy (I don't know).




    LONG MAY YOUR BRICK FLY!

    Ride Safe, Ride Far, Ride Often

    Lee Fulton Forum Moderator
    3 Marakesh Red K75Ss
    Mine, Hers, Spare

  14. #14
    My '90 K75s has the same issue, lock barley turns at all and does not lock. No movement in or out. Mine is very much original at two owners and 12K miles. Both the ignition key and the side case keys fit in. (ignition is the folding key) As the ignition key is the one that works with the seat/helmet lock I am assuming it would also be the one for the fork lock. Will try some penetrating oil and see if it helps, but I really don't use it anyway. I am just rather anal and like everything working as it should.

Similar Threads

  1. fork lock question '94 K75RT
    By SUNNYBEAR in forum Flying Brick K-bikes
    Replies: 3
    Last Post: 08-05-2011, 02:23 AM
  2. R90/6 fork lock
    By DAVIS2X1 in forum Airheads
    Replies: 10
    Last Post: 04-19-2010, 02:29 PM
  3. 1975 R90/6 Fork Lock
    By zabeathome in forum Airheads
    Replies: 4
    Last Post: 09-14-2009, 07:22 PM
  4. How do you remove the R75/6 fork Lock
    By ripperfarms in forum Airheads
    Replies: 1
    Last Post: 08-15-2008, 01:31 PM
  5. /2 fork lock key blanks
    By bensonhurst in forum Vintage
    Replies: 2
    Last Post: 06-20-2006, 03:12 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
  •