BMW K bikes have a variety of
locks. Many times a K bike will have more than one key.
A common example is that the side cases have been
purchased separately and use a different key than the
ignition key. Fortunately, for many of the locks, the lock
cores can be removed and modified to
work with a particular key.
The basic procedure is pretty
simple: remove the lock core, insert the key that you want
to use and file down the tumblers (a.k.a. wafers) sticking
Here's a K bike lock core. (from
a system case lock) They are all basically the same with
respect to how they work. They have six metal slats with
tiny springs in them. Since we're dealing with locks, I'll
call them the "tumblers." The last tumbler is what holds the
lock core in the lock. I call it the retainer tang.
Do not file down the retainer one at
What you do to make the lock work
with a particular key is to insert your key and then file
down (I use a Dremel grinding wheel) anything that sticks
out. Here's a lock core from a 35L top case:
To rekey a lock core, insert the
"new" key and then file down anything thing sticking out -
except for the very last one as that is what holds the lock
core in place in the lock:
The table below lists the various
locks on K bikes and has some comments on rekeying each.
spray silicone or a lubricant specifically made for locks.
Do not use
WD-40. It is solvent based water displacement (WD)
formula and does not contain any actual lubricants. It
captures dust and can gum up locks over time.
tricky because you need to pop the metal cap off
of the top along with the springed "door" and
then reinstall them but it is possible. For this
reason, I usually modify the bike's other lock
cores to match the ignition key.
2V Steering Lock
tried. Don't know.
System or City Case
22L Top Case
35L Top Case
Low Seat Lock
RT/LT Radio & Bucket Covers
put a ton of effort into it but I've never
figured out how to access the lock tumblers on these. For
this reason, if one of your covers ever gets
broken don't just throw it away without first
saving the lock from it.
4V Ignition (K100RS4V, K1, K1100)
The 4V ignition switch is held
into the upper fork tree by two security bolts whose heads
break off when they are installed at the factory. In order
to remove the ignition switch from the fork tree you need to
drill the heads off of these bolts and push the ignition
switch assembly down.
When drilling the heads off of
the security bolts first use a small drill bit to drill a
shallow pilot hole in the center of the bolt head. This will
make it easier to keep the larger drill bit centered when
drilling the bolt head off.
When reinstalling the ignition
switch back into the upper fork tree these security bolts
can be replaced by regular M8x30 socket cap bolts.
Once the 4V ignition switch is
removed from the upper fork tree, stick a pin or whatever into the
small hole shown below and wiggle the key to remove the lock
While you have the ignition lock
removed you may want to spray some silicone lubricant into
the fork lock bolt to keep it well lubricated.
If you're replacing the wiring
harness (part 61322305292) then you need to loosen the grub
screw a few turns:
System Case or City Case
Turn the key to the open
position, open the lock, turn the key to the locked position
and then use a 3mm or 4mm Allen wrench at the back of the
lock core to depress the retainer tang. Then slowly wiggle
the lock core out:
Liter Top Case
In order to rekey the lock for
the 22 liter top case you will need the original key to
remove the lock core from the lock body.
The lock is held into the case by
a large plastic nut that you should be able to unscrew by
hand. Once loosened you'll need to press the lock in so that
the hook opens up in order to get the nut all of the way off
and remove the lock from the case.
In order to depress the retainer
tang you'll need to turn the key to the unlocked position.
While depressing the retainer
tang with a pick or pin, turn the key/lock core
counter-clockwise into order to get the lock core out of the
Then insert the "new" key into
the lock core and file things down as described at the top
of this page.
Liter Top Case (K1100LT)
If the 35L top case is unlocked
then you can rekey it to a "new" key without having the
1 - Unscrew the three Phillips
screws from the left inside of the case:
2 - When you remove the lock
assembly don't lose this part that will fall out:
3 - Use a pick or pin to depress
the tang that holds the lock core in and push the lock core
4 - Fully insert the "new" key
into the lock core and use a rotary tool (a.k.a. Dremel) to
file down anything that sticks out. Be careful not to file
down the last one as that is what holds the lock core in the
5 - Insert the lock core back
into the lock body.
6 - When screwing the lock body
back onto the case install the piece from 2) above like
7 - Before closing the lid and
locking the case, experiment to make sure that the lock now
unlocks and locks as it should with your "new" key. You
don't want to close and lock the case and then not be able
to unlock it.
I recommend doing this off of the
bike so parts don't fall into the tank. The gas cap is
removed by unscrewing the four countersunk Phillips screws
you see around the perimeter when the gas cap is open. Since
they are mounted in aluminum, the dissimilar metals can
cause corrosion in the threads. Therefore you need to be
careful removing them or you can strip the heads of the
Phillips screws. First clean out the heads with a dental
pick or something so that you can get a Phillips screwdriver
all of the way in. Then, using your best fitting/best
quality Phillips screwdriver apply a lot of downward
pressure while initially turning the screw to break it free.
Once you have the gas cap off of
the bike remove the three Phillips screws that hold the lock
assembly to the gas cap.
Then use a screwdriver or
whatever to depress the retainer tang and remove the lock
Putting the gas cap back together
can be a little tricky installing the cup and return spring
properly. Start by putting the return spring in with the
part sticking out at a right angle positioned in it's groove
in the lock housing:
Then put the "cup" on so that the
groove on the bottom of it sits on the center straight part
of the spring:
Applying constant downward
pressure, slowly turn the cup counterclockwise until you
feel it drop into place:
Then carefully reattach the
assembly to the gas cap with the three Phillips screws.
Sometimes the little bucket with
the cam on it won't stay in place. If this is the case
then hold the cup in place with a pen or screwdriver through
the lock hole in the gas cap lid while reassembling. Once
the assembly is held onto the lid of the gas cap that will
keep it in place.
Remove the seat lock from the
frame by unscrewing the two 8mm nuts on the back of it and
the two small Phillips screws from the front. Use some small
screwdrivers to break the face plate off of the rear
housing. It will look like this:
(Hopefully your seat
lock hook isn't busted off like this one. It's just an old
one I'm using for demo purposes here.)
Pop the latching bars out of
their pivot and then you can remove the lock. Use a dental
pick or sewing needle to depress the retainer tang and
remove the lock core:
Once you've modified the lock
core, glue it back together with some epoxy or JB Weld
around the outer edge. One nice thing about the design of
the seat lock is that the two bolts at the bottom that
attach it to the frame help hold it together.
Remove the machine screw on the
back of the lock. Insert the key and pull inner assembly
out. The lock core can be removed by depreesing the reatiner
© 2018 Drake Smith - Please do
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