Topic: Re-keying locks, how to.

[DonD]

I have enjoyed many of the "tricks and tips" on the board, so I thought I would add my tiny contribution for my fellow cheapskates.  This post details how I re-keyed my steering lock.  Seat locks are similar.

My 1971 CB750 was constructed from three different bikes while I was in college.  The ignition/key switch had the tumblers drilled out by someone (not me), so I was able to use a standard screwdriver to start it.  That was fine for college (when I was really poor).  My Dad used the bike off & on for 10 years, and recently gave it back to me.

I decided to order a new switch.  Not the expensive nos switch, but the cheap aftermarket version.  I needed the round electrical plug, but the aftermarket version with the round plug came with a newer style key that wouldn't fit the seat or steering lock.  I ordered the ignition with the newer style "rectangle" plug and correct "T" style key.  Then I switched the connectors.


Now I wanted to re-key my steering lock and also re-key the extra seat lock from a 1974 model I had to match the keys that came with the new switch.

Getting the steering lock out was a pain.  It requires the correct key to be removed.  I spent an hour with a tiny allen wrench, a small screwdriver, and substantial cussing attempting to pick that lock.  I was about to give up when the lock turned and fell into my hand, leaving me with this.  (Sorry for the poor quality photos.)


The first thing to do is remove the external spring and the roll pin which holds the two main parts of the lock together.  Use a pair of vise-grips.  Grip it tight, twist and pull until it pops out.  Don't worry about crushing the roll pin a little.  It can be re-used as long as one end doesn't get damaged.


Now the two pieces can be separated.


This leaves the main lock mechanism.  Next, take a very small regular screwdriver that you have no love for and file the sides of the tip to make it narrow.  Then file the tip to "sharpen".  The screwdriver must be able to get under the thin strip of brass at the top of the lock.  Work the end of the brass up until it can be grabbed with pliers and peeled off.  BE CAREFUL TO NOT DESTROY IT.


Now the tumbler tension springs are visible.


Turn the assembly up-side down and gently tap until the three springs and six tumblers fall out.  Now the lock can be further disassembled.


The three equal-length short tumblers at the top of the above photo (just below the springs) are to be left alone.  Only the three odd-sized tumblers at the bottom of the photo will be modified.

Take the new key and insert it into the lock.  Place the tumblers, rounded side down, into the holes.  Re-arrange them until they fit best.  "Fit" meaning that each tumber sticks up either flush with or higher than the outer diameter of the lock.  Notice in this photo the three bumps sticking up from the lock.


Sometimes you can just re-arrange the tumblers and have them all fit flush with the outer diameter of the lock.  That is what we are going for.  The tops of those tumblers need to be flush with the outer diameter of the lock.  A dremel works well to shave them down to size.


There, now the lock is re-keyed!  It just needs to be re-assembled.

Leave the key and tumblers in the lock barrel as shown above.  Slip the barrel back into the lock housing.  Put the three smaller tumblers back in the housing.  Now put the springs in behind them.  Hold the two pieces of the lock together and SLOWLY remove the key.  It should look like this.


Almost done, the brass strip needs to be replaced over the springs.  First flatten it out with pliers.  Now it needs to be shaped, lengthwise, into a "V".  I used a chisel, small hammer and some cardboard to get it started.


The chisel will only get the "V" shape started.  Increase the angle of the "V" by SLOWLY crimping it with a pair of pliers.  Now place the brass strip with the tip of the "V" facing up back over the three springs.  Use pliers to smash it back into a flat shape as much as possible.  Then use the roll pin and pliers to crush it the rest of the way into its original flat shape.


Now put the two main pieces of the lock back together and re-install the roll pin with a small hammer.  Re-install the external spring and it should now look just like it did at the beginning!


Put the lock back into the bike and enjoy!

[mystic_1]

Great write-up.   I've done similar things myself with good results.

mystic_1

[Raul CB750K1]

Yep. I've done it myself but never took pictures.

May I suggest a tip? When you want close-up pictures, if you put the camera close to the object, you will get two undesired effects: the camera won't be able to focus, and the picture will get too white because the flash is so close that the reflection is so powerful.

Next time just put the camera farther away, say 1.5 to 2 feet, and then use the zoom to take a close-up picture. The camera will be able to focus -you will need the object has enough light so the camera is able to focus- and the flash will not "burn" the picture, because the distance is longer and the reflected light arrives attenuated at the camera CCD.

[Raul CB750K1]

Opps, and I forgot, don't depress the button at once. Depress it halfway, so the camera focus and calculate the light conditions. When the screen shows you the sign that is ready -flash loaded etc-, without releasing the button, fully depress it. Otherwise it will shoot with the setup calculated for the previous photo.

[Artfrombama]

Yep. I've done it myself but never took pictures.

May I suggest a tip? When you want close-up pictures, if you put the camera close to the object, you will get two undesired effects: the camera won't be able to focus, and the picture will get too white because the flash is so close that the reflection is so powerful.

Next time just put the camera farther away, say 1.5 to 2 feet, and then use the zoom to take a close-up picture. The camera will be able to focus -you will need the object has enough light so the camera is able to focus- and the flash will not "burn" the picture, because the distance is longer and the reflected light arrives attenuated at the camera CCD.

Cellphone pics?
This thread would have been much better with clear pictures. Something I'm going to have to tackle because the ignition key won't work with the seat lock.

[DonD]

Thanks for the picture tips guys.  I took them with my nice, new Kodak digital camera.  The photos looked good in the display, but turned out horrible.  I thought that I was just too close to the subject and confused the auto-focus.  Unfortunately, I'm not going to re-key any more locks for a while, so am stuck with what you see. 

[mystic_1]

Many digital camera have a mode known as "Macro Mode" for close-ups.  On my Panasonic camera the icon for this is a little flower.  This allows you to take pics at distances less than two feet without confusing the auto-focus.



Back to the subject of re-keying locks, another tip is that, if necessary, you can simply leave out tumblers that aren't the right length instead of filing them.  Really you only need one tumbler to make the lock work, more tumblers just add security and make the lock harder to pick.  Also, some lock designs have the tumblers sticking up AND down out of the lock barrel, these sort of tumblers are harder to modify so if some are not the right size, just leave them out.

mystic_1

[Blasbo]

I recently went through the same thing with my 77 CB750 but the lock came apart completely different. Also had rotten plastic parts that I found replacements for at partsnmore.com.
Question - who did you get the ignition from?

[DonD]

Blasbo,

I bought it from DennisKirk.  I bought the same one from them back in 1999 for my 1974 CB750 and had no problems with it.

http://www.denniskirk.com/jsp/product_catalog/Product.jsp?skuId=200728&store=Main&catId=412&productId=p200725&leafCatId=41208&mmyId=7716

[Aaron J Williams]

Excellent write up. I have never tried this but you make it look pretty easy, Thanks!