Mechanical Clock Pendulums

Mechanical Clock PendulumsTypes of PendulumsMeasuring Hermle CMInstallationIf Length Is Not StampedStick Pendulum AssemblyPendulum TimingUrgos UW Lyre Note

Please view these information tabs to help with determining the proper Mechanical Clock Pendulums for your clock.

Types of Clock Pendulums

There are typically three Types of Clock Pendulums used on mechanical clocks. There is the brass rod style pendulum for small shelf or wall clocks, there is the metal Lyre style pendulums for floor clocks, and then there is wood stick pendulums that are used on everything but mantle clocks.

Metal Lyre

Types of Clock Pendulums

A metal Lyre style pendulum are used for floor clocks, in other words for grandfather and sometimes grandmother clocks. We offer these for German post WW2 units such as Urgos, Kieninger, Jauch and Hermle units. These are the only post WW2 German units made, despite the fact it may something other than these names, as the movements were made for various other companies who was able to get there name on the movements instead of who really made them. The Lyre types of clock pendulums are for more of a modern look, if your looking for an antique look instead, please consider the wood stick style as an alternative.

Wood Stick

Wood stick style clock pendulum

The wood stick will come unstained. This is so the stick can be stained the proper color to match the clock case. The wood stick pendulum consists of the stick with the hardware and also the bob in the diameter chosen. The good thing about wood stick pendulums is they can be shortened if needed.

Brass Rod

Types of Clock Pendulums

The brass rod types of clock pendulums are usually used on shelf clocks or wall clocks. Sometimes they are used in grand daughter or grand mother clocks, but this is typically not the situation. These cost more for two reasons, there made of brass and also they are custom cut to size by us here at Clockworks. We will cut it to the exact length you need for your specific clock movement upon your ordering.

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Hermle Clock Pendulum Measuring

Hermle Clock Pendulum Measuring is done in combination of the CM number and the pendulum bob diameter. The CM will only be accurate to the pendulum length if the pendulum bob is small. If it has a larger bob it will be a longer pendulum. The larger the bob, or the heavier the pendulum, the longer it needs to be. Best to email [email protected] if you need the exact info on how long your pendulum should be. We would need the CM number off the back plate, and also how wide the pendulum bob is (round disk at the bottom of the pendulum).

The pendulum length (**cm) will be from the suspension post all the way down to the bottom of the pendulum nut threads. The length includes the pendulum from tip to tip, the leader it hangs on, and the suspension spring. This pendulum length will not always be exactly what is marked on the movement. There are other factors such as the pendulum bob diameter. The larger the pendulum bob diameter then the longer the pendulum length despite the CM length.


If the CM length on the old unit matches the CM length on the new unit, this is all that is needed. Sometimes it is required to use the old leader and put it on the new unit. If both CM numbers match and there is still a timing issue, it may had the wrong pendulum. The next question would be, did the clock ever keep time with the pendulum it had?

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Mechanical Clock Pendulum Installation

Mechanical Clock Pendulum Installation is done by these steps. Just an interesting point first, typically pendulum makers are not movement makers and these two things are married together by a person or place such as instead of the movement manufacturer. This is interesting because it explains why there can be so many variants of pendulums available for one movement. Options for the material the pendulum is made of such as a brass rod, wood stick, or metal lyre style as far as what its made out of. Then you have what bob diameter to get for the clock case so it both looks good and at the same time no t wack the sides of the case. The length of the pendulum has to be close to time range length dictated by the movements internal gearing, the top hook has to be in a way to hook up to the movements pendulum leader also. Why is all this mentioned? Because sometimes an old pendulum will not hook to the new movement the same way as it did in the past and you may or may not need a new top hook for the pendulum. Also mentioned so it is clear that any old pendulum will not just work in the clock unless your really just that lucky. The pendulum and the movement sort of need to be married by me or you to get the right one.

If the new pendulum leader is not installed, you will need to put the pendulum leader onto its suspension spring and hang it on the back of the clock. This is done by removing the set screw on the top of the suspension spring. With this set screw out, you can lower the suspension spring and hook on the leader hook to the bottom of the suspension spring and bring it back up to original position. Reinstall the set screw and then Hang the pendulum onto its pendulum leader.

These are the steps at this point

  • 1. Make it run, by putting in beat
  • 2. Install the hands
  • 3. Adjust the chime hammers
  • 4. Make it chime
  • 5. Set the hands to time
  • 6. Make it strike

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Mechanical Clock Pendulum Length

Mechanical Clock Pendulum Length is discussed here, when there is no indication of what it should be on the back plate of the movement. If you have numbers on the back plate this is a good thing and can tell us the length automatically. However some movements do not have any numbers on the movement so it is not known what pendulum length should be on the clock so it keeps time.

In other words if you need a pendulum for a clock, the first thing is to look at the back plate of the clock movement for the numbers stamped into it. There should be, in most cases, an indication of how long the pendulum should be to keep approximate time, if it is a German made movement. Providing it’s of German origin, it will usually have a CM length or a PL length. CM stands for centimeters and PL stands for pendulum length. Even if the CM stamp is not on the movement, any numbers can just tell us the pendulum length automatically. If the movement was made post WW2 in Germany like most modern floor clocks, the numbers will tell us. Even though it does not say something like 114CM or just 116 on the movement, the numbers that are there can do the trick such as UW32/1. Please email us at [email protected] these numbers if its German and we will figure it out for you.

If it is German, keep in mind the CM length is not the actual pendulum length. Usually the Germans measure this length from the top of the clock movement, and this includes the three components of the pendulum all in one length in centimeters. This length will include the pendulum itself, the leader that it hooks to, and the suspension spring on the top that the leader hooks on to, all in one CM measurement.

If the movement is prior or during WW2 it may have no indication regardless of where is was made. Modern Korean or Indian units do not have it stamped either. This makes it complicated to get the pendulum length.

Mechanical Clock Pendulum Length - no numbers on it

If the movement has no numbers on the back plate at all, or if there is no known conversion, the best style of pendulum that you can get is a wood stick pendulum. This is the only style of pendulum that can be easily modified. These types of clocks are usually antiques, or of Asian origin, and information such as pendulum length is just simply not available. In this case, the only thing to do is make an educated guess on where the manufacturer intended to have the bob swing back and forth and create a pendulum to that measurement.

To do this, measure from the bottom of where your imaginary pendulum bob would be in the case up to the leader that the pendulum is to hang on. Take this measurement and add approximately an inch or two. This will give you the longest possible length that the pendulum would be in the clock. So now with the longest possible length known, get a wood stick in the length you just measured, as well as a top hook that looks like it will attach, or be modified to attach, to the leader.

Also, from that same link, you can purchase a new bob, if you need one. To get the proper bob size, measure the inside width of your clock case and subtract 4 inches from that measurement. That measurement would be the largest bob size that you could order without worrying about the bob hitting the sides of the case. If you want to go smaller than that measurement, then that is fine too.

Once you receive your new pendulum components, you can now put it together, install it, and see how the clock runs. Remember, the pendulum is going to be at its longest possible length. The longer the pendulum, the slower the time will be. If the clock is running too slow, even after adjusting the bob, you can shorten the stick until the clock is close to keeping the correct time. Start off by shortening the wood stick by an inch and a half, put all of the components back on the pendulum and see how the clock runs with the new adjustment. If it is still too slow, remove the components again and cut off a half of an inch or an inch. This is the procedure to follow until you get the pendulum to the correct length so that the clock keeps the correct time.

There is another way, its called setting the beat rate. This is a more involved way and usually just done by clockmakers. It involves a beat detecting device that counts out the beats per hour, or the beats per minute. To do this you would need to know what the beat rate is supposed to be for that particular movement first, and then keep adjusting the pendulum length till you have it keep time. There are cell phone aps out there these days that will tell you the beat rate and the cell phone will listen and tell you if the clock will keep time with that pendulum. You go longer or shorter until your phone says the beat rate is set. I have never used these so I cant say much about them, except the app is cheap and people seem to like them. We use the machine here so we never got into the cell phone app yet.

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Wood Stick Pendulum Assembly

Wood Stick Pendulum Assembly is required as the wood comes unstained, usually it gets stained the color of the clock case or painted black. Either way its left to your own creativity on that, what color stain you would like for the wood stick. The following is when you are ready to put the wood stick pendulum together, here are some guidelines.

  • 1. Drill the pilot hole. To assemble this pendulum first you drill a pilot hole in one end of the wood stick and then thread in the threads with the rating nut on it into the hole you drilled. You would take the rating nut off of the threads and then use some pliers to twist the threaded rod into the wood and shorten the length.
  • 2. Insert the bob. The bob is the round disk that goes onto the end of the pendulum stick on the threaded rod that was just installed. The bob has two holes on the back, slide the wood stick in with its threaded rod from the big hole on the top down and through the smaller hole on the bottom. So when this is done you have the stick going into the top of the bob and the threaded rod hanging down below the bob. Now you just put the rating nut back on the threaded rod under the pendulum bob and screw it upward some to about the middle of the threaded portion, and slide the bob down on top of it. This is how the clock is adjusted to keep proper time, if the clock is slow than the rating nut will be turned to raise the pendulum bob some.
  • 3. Mount the top hook. The top hook mounts to the other end of the stick with the hook facing the opposite side of the shiny bob. So the hook will point to the back of the movement in other words. This top hook has tabs you can bend over with the pliers, usually the hook gets placed on the top of the wood stick and both the tabs on each side can be squashed inward as to create a good friction fit so the hook will not slide off.

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Mechanical Pendulum Clock Timing Issues

Mechanical Pendulum Clock Timing Issues for post WW2 German made mechanical clocks is the discussion in this section. There are two things that need to jive with each other. The length of the pendulum, and the gearing inside the movement. When they made the movement, they put certain wheels in the movement so it would keep time at a certain pendulum length. So if the clock is fast or slow with a movement, and you want to use that same movement and not a different one, the only correction left to do is alter the length of the pendulum. Sure the weight of the bob or how big the bob is matters also, but in the end we are only talking about the length. Without adding weight, or getting a new bob, without any of these things, if you alter the pendulum overall length it corrects the timing with whatever bob you have on the clock.

Where it can be altered

The pendulum length is considered overall and not just the pendulum. For example if the clock says 94cm on the back of it, this is the way the Germans measure there pendulum lengths from the top of the movement and all the way down. This will include the suspension spring way up top, the pendulum leader or guide you can call it, and also the pendulum from tip to tip all with a 4 1/2 inch bob diameter. Of course the larger the bob, the longer it will be beyond that 94cm measurement.

So what this means is the length can be altered by either the pendulum itself or the leader it hangs on, it does not matter. So in some instances with a lyre pendulum that is still fast with the bob all the way down, its possible to add material to the leader its hanging on to get more length out of it since its not easy to do with the lyre pendulum itself.

How to Time the Movement

A shorter pendulum will make the clock run faster. A longer pendulum makes the clock run slower. So if you are always late for work all you need to do is raise the bob at the bottom of the pendulum by turning its nut below it. The more raised the bob, the more it will speed up time. If your at the end of the adjustment, the bob is all the way up and its still too slow, you can shorten either the pendulum itself or the leader it hangs on to correct. 1 3/4 inches is a good measurement to make one of these longer or shorter as needed, as this is the length of the threads at the bottom of the bob. So it will give you a full timing adjustment range all over again and you can go up or down to fine tune as needed.

Used to keep time at one point

If the clock kept time in the past and if the clock is running fast where before it always kept good time, this means the escape wheel is worn and it is advancing more than one tooth at a time. The escape wheel alone would be hard to find, and hard to replace as the entire movement would be disassembled to replace this. The cost of having someone do this for you would be the same price as a new movement. There is no such thing as having a repair on a clock movement being better than a new movement and the price would be about the same. Often enough the new movement would be less money than a repair. So what all this means is to first see if the clock movement is in production and available new instead of having it overhauled. We do this by getting the numbers off of the back plate of the movement itself, right off of the brass, then email this information to us at [email protected] and we will check availability and quote. If the movement is not in production anymore, then a repair is the only option.

Mechanical Pendulum Clock Timing Issues - Conclusion

Mechanical Pendulum Clock Timing Issues can be resolved by altering the length in the overall pendulum assembly, or by raising or lowering the pendulum bob. If the clock kept time in the past and now too fast, its time for a new movement and has nothing to do with the pendulum

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Urgos Lyre Pendulum Availability

Urgos Lyre Pendulum Availability is none. But we can make a new Lyre pendulum for your UW Urgos clock movement custom here at What we do is take a Hermle Lyre pendulum that is still in production, and solder a new top hook to the pendulum at the length you need for your specific clock. This solder or riveted on top hook, will be noticeable on the pendulum itself but when hanging on the clock no one will see it.

Please understand that we will do our best to guess what length to make this pendulum but there is a chance that the pendulum would need to be shortened or made longer beyond the adjustment of the threads of the rating nut. This means you may have to cut the leader and make it shorter or the top of the pendulum if you need to make the clock pendulum shorter to speed up time and make the timing accurate. It will be helpful also if you can email a picture of the bottom of the pendulum leader that the pendulum is supposed to hang on. We need to be sure we adapt the correct top hook on the pendulum to hook to this part.

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The below Mechanical Clock Pendulums are for German post WW2 clocks. The four clock movement manufacturers are listed below. If you do not know who made your clock movement, but it says made in Germany, please see the below number examples. If the numbers are similar to what is below, that is who made the clock movement. This is important to know who made the movement, because then we can provide the correct pendulum that will hook up and keep time. After you know who made your clock movement, its time to decide if you would like a metal lyre style pendulum, wood stick or the brass rod style for wall / mantle clock only.

Clock movement identification clockworks
Hermle Hermle Clock Pendulum Hermle clock movement identification
Metal Lyre Lyre style metal clock pendulum
Wood Stick Wood stick style clock pendulum
Brass Rod Brass rod clock pendulum

Kieninger Kieninger Clock Pendulum Kieninger clock movement identification
Metal Lyre Lyre style metal clock pendulum
Wood Stick Wood stick style clock pendulum
Brass Rod Brass rod clock pendulum

Urgos Urgos Clock Pendulum Urgos clock movement identification
Metal Lyre Lyre style metal clock pendulum
Wood Stick Wood stick style clock pendulum
Custom Rod Brass rod clock pendulum

Jauch Jauch Clock Pendulum

Custom, please email us the movement numbers [email protected]

Custom Lyre Lyre style metal clock pendulum
Custom Stick Wood stick style clock pendulum
Custom Rod Brass rod clock pendulum

Clock Pendulums Grape Leaf

Gold tone brass pendulum with leaf decorations on the top of the pendulum bob. Seven inches in length and has a 2 1/2 inch diameter bob that weighs 3.5 ounces. Used with some modern wall and 31 day clocks. This pendulum has a top with a hole in it, so it would hang on a clock with a single hook leader.

PD28: $19.89
Clock Pendulums R and A style

R and A style Mechanical Clock Pendulums with a hook top and the rating assembly on the bottom to regulate the time. The pendulum is 9 1/2 inches (241mm) long, with a 3 1/2 inch (90mm) wide bob. The R and A stand for Retard or Advance as the time keeping is controlled by the rating nut on the bottom of the bob, lower is slower.

PD44: $29.89
Clock Pendulums Kitchen Pendulum

Pendulum with a hole top mount for kitchen or gingerbread style clocks.This is a 7 inch pendulum from tip to tip. This would hook to a modified long suspension C from the pendulum parts page.

PD14: $19.89
Clock Pendulums Universal Pendulum

This pendulum can be used for many French or Ansonia clocks.The clock pendulum parts rating nut can be removed completely if needed and it can just be adjusted shorter with the set screw on the back. Just cut the rod shorter to what is needed.

PD18: $24.89$30.00
Clock Pendulums Mixed Bobs

We offer the above clock pendulums bobs with various patterns. These are for mantle movements with the F-S regulator that you can adjust the timing. This is because there is no rating assembly to adjust the timing.

PD10: $8.89
Clock Pendulums Adjustable Bob

This pendulum bob is threaded on the bottom with a rating nut for easy timing of the clock. This can be used on mantle clocks as well as certain wall clocks such as a banjo. Measurement is the diameter of the bob.

PD5: $12.89
Clock Pendulums Adjustable Mantle Bob

This is a 1 5/8 diameter 2.8oz adjustable mantle clock pendulum bob. This is the bob needed if there is no F / S regulator on the front of the clock dial that takes the skinny end of the key. This can be used in place of a F / S regulator as well if finding the right key is not easy. This is on a slider to regulate the time.

PD20: $19.89
Clock Pendulums Adjustable Pendulum

Popular brass pendulum style for antique clock movements such as Ansonia.Bob is 35mm in diameter and weighs two ounces. The top of the pendulum has the oblong hole as the mounting style.

PD22: $29.89