Clock Pendulum Parts

Clock Pendulum Parts for the mechanical clock pendulum assembly are offered on this webpage, such as bobs and suspension springs.
Pendulum PartsDefinitionsMissing partsLength infoTimingSuspension infoSuspension InstallLeader infoTop Hook info
Please view these information tabs to learn more about replacing clock pendulum parts.

Clock pendulum components description

Altogether, this is a description of the clock pendulum parts and components. Please use this as a glossary of the parts to a clock pendulum assembly. Knowing the correct terms for the various pendulum parts is helpful when locating replacements. We are pretty adept at deciphering descriptions of parts however knowing the name is always something we welcome.

The clock pendulum

First, a clock pendulum includes the bottom rating nut and threads, the pendulum bob, and top hook. Additionally, these items are removable on wood stick pendulums only. Lyre metal clock pendulums do not have the ability to come apart.

Clock pendulum leader

Second, a leader is the part that the pendulum hangs onto when it is installed on the clock. It then in turn hooks to the suspension spring on the very top of the pendulum assembly. Naturally, pendulum leaders vary depending on the manufacturer of the clock movement and they can also vary in length as well as style. Sometimes there can be more than one type of leader for the same movement. There are also instances where we custom make leaders for customers.

Suspension spring description

The clock pendulum suspension spring is the short spring steel part on the very top of the pendulum assembly. Its purpose is to suspend the leader and pendulum in the air. Generally speaking, its steel spring like strips flex to let the pendulum swing back and forth with ease and momentum.

Clock Pendulum Components Complete

In summary, the clock pendulum components description includes the pendulum hanging on the leader and the leader hanging on the suspension spring. Put the complete pendulum assembly on the clock and it is ready to go. The next step is to put the clock in beat and run the clock to see how the time keeping is.

Clock Pendulum Components Description

Leader and suspension

Clock Pendulum Components Description

Pendulum leader

Clock Pendulum Components Description

Suspension spring

Clock Pendulum Components Description



Replacing Lost Pendulum Parts

By and large, replacing a lost pendulum part from its assembly is a process. It is more complicated than just matching up the broken pendulum part. Certainly, narrowing it down requires a different method than just observation. The following text will guide you through that process.

The lost pendulum

First, identify the movement manufacturer. This is the beginning step to identify a lost clock pendulum. This is done by getting the movement numbers off of the back plate of the movement itself. That is to say, it will not be in the manual that came with the clock. Moreover it will also not be on any stickers or the clock case. Match the movement number here to find out who made the movement. Finally, proceed to the pendulum page. This is the first step in replacing a lost pendulum as well as replacing lost pendulum parts.

Lost pendulum leader

The leader hooks to the suspension spring. The suspension spring is located at the top of the movement. The pendulum hangs onto the leader. All or some of these parts are what you need to order to replace lost pendulum parts. Again, the order of the parts is the suspension spring, the leader, then the pendulum.

If the leader is missing, identify who made the movement. Use the above information to correctly identify the movement so it is possible to replace the pendulum part. The leader possibilities are narrowed down considerably upon knowing who made the movement. This makes things much easier when replacing lost pendulum parts. After knowing the manufacturer, match the information to a leader shown on this page. In the final analysis, visually inspect the pendulum hook style, the crutch on the back of the movement, and the suspension hook. Finally, compare the components of the clock to the options in that manufacturer category to figure out the best one. Replacing lost pendulum part can be tricky however with these descriptions the task should be less daunting.

The lost suspension spring

First know that style A is the very most common suspension spring style in existence. Check the top of the pendulum leader and if there is a double hook on the end it will be style A required for the clock. Generally speaking, style A3 is used for large grandfather units, A2 for grandmother and wall clocks, and A1 for mantle clocks. Suspension spring are one of the easier parts to ascertain when replacing lost pendulum parts.


The mechanical clock pendulum length

A pendulum clock without a pendulum is a shame for sure. Hence, getting the mechanical clock pendulum length correct does take some diving into the clock world. If you have no idea what pendulum it would take, this is a basic guide. Of course, this is a basic guide to narrow it down to the best pendulum for your clock. This will cover most situations, without special equipment to figure out the length.

The movement CM or PL stamp


Mechanical Clock Pendulum Length for German made movements


If no stamp try to convert


Converting numbers to CM length


Converted number example


German grandfather movements


American clocks


No luck

If everything fails for one reason or another, the best chance for a pendulum is the wood stick style. This is the only style of pendulum that can be easily modified because you can chop it. These types of clocks are usually antiques, or of Asian origin, and information such as pendulum length is simply not available. Sometimes it takes a good guess on where the manufacturer intended to have the bob sit.

To do it this way, you only need a pendulum with a stick that is way too long to begin with. Chop it, try it, chop it, try it. Each time your slow, cut an inch and half off of the sticks length and hang it back on. It will only take a couple of times, and if you start way too long you can always go shorter.

Clock makers method for Mechanical Clock Pendulum Lengths

There is another way, its called setting the beat rate. This is a more involved way and usually just done by clock makers. It involves a beat detecting device that counts out the beats per hour, or the beats per minute. To do this, first you would need to know what the beat rate is supposed to be for that particular movement, and then keep adjusting the pendulum length until you have it keeping time. There are cell phone apps 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.

Contacting us for help with Mechanical Clock Pendulum Lengths



Timing a mechanical pendulum clock

Timing a mechanical pendulum clock is all about the overall pendulum length and rarely has anything to do with the movement itself. A mechanical clock is easy to time providing you have the correct pendulum. When the pendulum is correct for that particular movement it will hang on the leader and keep approximate time. The fine timing can be done only with the pendulum adjustment located at the very bottom. At the bottom of the bob is some adjustment threads and a nut. To turn the nut one way raises the bob and the other lowers it. A shorter pendulum will make the clock run faster. A longer pendulum makes the clock run slower.

Fine timing the clock


If there is no more adjustment



German pendulum length CM stamp


Used to keep time, now does not



Mechanical Pendulum Clock Timing Issues - Conclusion



Does not have to be exact

Naturally, suspension springs do not have to be exact in length. If the clock runs slow, simply raise the pendulum bob with the rating nut at the bottom. Likewise, if the clock is running fast then turn the rating nut to lower the pendulum bob.

Most common springs

By and large, suspension spring A is the most common style suspension spring. Of course, it is most likely the one by default. If the old suspension spring looks similar to this one then it is right. As a general rule of thumb, small mantle clocks take suspension A1, wall clocks and small grandmother units will take suspension A2. The A3 size is for grandfather clock units with a larger pendulum bob diameter. This size can also be seen on Grandmother clocks with larger bob diameters. The larger A3 is used with large bob diameters so the bob will not wobble front to back. If using a pendulum with a bob of 8 1/2 inch diameter or larger please order Suspension A3 for this reason.

Not as common

Urgos uses the single hook style as seen in picture suspension B. However suspension A was the very most common to use. Very old antique round movements mainly use Suspension C and Suspension D. These are mainly French clocks and US made units made prior to 1945.

Suspension Spring Installation

There are two ways that the suspension spring can be held into the suspension post. One way is to use a thumb, or set screw. When ready, just remove the screw and the suspension spring will fall out of its slot. Another way is to use a tapered pin. This is a pin that is skinny on one end and wide on the other. Push the skinny end through the pre-drilled hole in the suspension post. Push it through the hole in the suspension spring all the way to the other side of the post. Remove it using needle nose pliers. Twist and yank it out from the wide side. Please note, some set screws may be too wide for the suspension top hole. In this case, use a tapered pin to secure the suspension spring instead of the screw.

Connect the leader

Hook the leader on the suspension spring prior to install. The intent is to have the suspension spring spring hooked and the leader engaged with the crutch. At this point the suspension spring can be lifted into position as you insert the set screw. Note that the suspension spring is lifted with the leader hanging on it while the leader is engaged with the crutch as one unit.

What is next

Hang the pendulum on the newly installed leader. Now, give the pendulum a good swing, over swinging it so that it sets the correct beat. No mechanical clock with a pendulum, will run correctly if not put “In Beat”. Not familiar with this term? See the, “How to put My Clock In Beat” instructions.


Clock Pendulum Leaders

Mechanical pendulum clock leaders for post 1950 movements. These leader will fit clock movements made in Germany after WW2. The first step to replace a lost leader is to visually match one to the old leader. If the leader does not match up to any of the ones listed, please email us. A picture is always helpful. Look to see if the leader needs a double hook or a hole top in order for it to mount to the suspension spring. Similarly, check the other end and notice that configuration as well. What is the required mount style for the pendulum to hang on the clock? In the middle section, what one will engage with the swinging crutch on the back of the movement? These are all important factors to consider when replacing the leader.

The length of the leader

If the leader is missing, however, there are some more steps to figure out what the leader length should be. Not all leaders have variable lengths and the ones that do are for Hermle and Kieninger clock movements only. Kieninger is easy. Those leaders only come in two lengths. Grandfather clocks by Kieninger take the 7 inch leader. Wall and mantle units take the shorter leader. Hermle leaders are much more involved. Determining which leader is the correct length for a Hermle is a process. The next section will describe the ones available.

Hermle leader lengths

A Hermle floor or wall clock will always take leader D or G. leader E is for a low bridge to a high bridge conversion on a Hermle grandmother clock. Therefore, this can be eliminated from the choices if a conversion is not being done. The next choice is leader F which is for mantle clocks. This one is also used to create custom pendulum lengths. Additionally, leader F and leader G are interchangeable. So if a custom leader G is needed, a leader F can be used in its place with an alternate length. Please email us with any questions about Hermle leaders.

Leader F for Hermle mantle

Usually mantle clocks with a Hermle clock movement will take leader F. In a situation where the leader is missing and the length is unknown, the following steps need to be taken. This will ensure that the correct leader length is chosen. First, use the CM number off of the back of the movement. This CM length is the pendulum length from the top of the movement all the way down to the bottom of the pendulum. It is not the length of the pendulum itself. Often times this measurement can be confusing. It is important to measure this correctly. Failure to do so will result in the clock not keeping proper time.

Second step, is to take this CM length and divide it by 2.54 to get the inch equivalent. Then subtract the length of the pendulum and the suspension spring length from this measurement. The measurement that is left is the length needed for leader F. There are 1 1/2 inches of thread at the bottom of the pendulum for fine adjustment. Because there is so much room for adjustment, this measurement does not have to be exact. If there wasn't any extra length then it would need to be more precise. However this is not the case so close is good enough.

If the leader is the wrong length

The timing of a clock is determined by the length of the pendulum and the weight of the pendulum bob. This can get a bit confusing for some people. The overall pendulum length is stamped on the back plate of the clock movement with a CM number. This CM stamp is the overall pendulum length from the top of the clock movement all the way down to the bottom of the rating nut. This is based on the smallest bob diameter. Subsequently, a wider pendulum bob will require a longer pendulum. Again, this can get a bit tricky. Please feel free to send an email with any questions. We will be glad to help.

Often enough a clock will either run too fast or too slow. If the pendulum is too long, the clock will run slow. On the other hand, if the pendulum is too short the clock will run too fast. In addition, the wrong leader length will also create problems with accuracy. This may or may not be corrected by raising the bob up or down. This is done by turning the rating nut below the bob. If all else fails, a different leader length may need to be purchased. Before shortening a pendulum it would be best to contact us to see if this is the best option. Cutting the pendulum is the last resort.

In Conclusion

As seen, this is not a cut and dry procedure. There are many factors that play into getting the correct combination so the clock will keep correct time. The correct leader is just one part of the whole process. Sometimes all it takes is a leader that is a bit longer or shorter to correct an issue. There are also times where we have custom made leaders for customers. Measuring is also important. No matter what situation it is we can surely find a solution. Don't ever hesitate to reach out and ask a question. Pictures are always good to send so we can see what exists now. Email is always the fastest way to contact us.


Clock Pendulum Top Hooks

Mechanical clock pendulum top hooks replace broken top hooks or to build a new pendulum. This is a nice alternative to replacing an entire clock pendulum if the top is broken or missing. The top hook is the very top of the pendulum that will enable the pendulum to hang on the leader. To clarify, the leader is the 4 to 7 inch long bar that drives the clock pendulum back and forth.

What they fit

In fact, most of the top hooks here fit German post WW2 mechanical pendulum clocks. There are some top hooks that are for or can be used on antique clocks also. It matters only that the pendulum can hang into the air onto the leader and be stable. Antique clock pendulums can use any one of these top hooks if it will do the job.

How to install

The top hook installation is by friction only. Bend the tabs over and use a punch and a hammer to secure it to the wood stick. Another way is to drill starter holes into the top hook and secure with screws or nails.

Clock Suspension Spring

Suspension Springs

Suspensions are the top most portion of the clock pendulum assembly. Suspension spring style A is the most common that would be needed.

View Product
Clock Pendulum Leader Hanger


A clock leader is the part the pendulum hangs on to. The leader itself hangs onto the suspension spring that is on the top of the movement.

View Product
Clock Pendulum Top Hook

Top Hooks

Pendulum top hooks to replace broken tops or a new pendulum creation. Most offered are for wood stick style clock pendulums.

View Product
Long antique clock suspensions

Long Suspensions

Longer suspension springs for antique clocks. A and B are for antique tall case clocks. Style C is for antique wall and mantle clocks.

View Product
Clock Pendulums

Rating Nut and Threads

A threaded rod with its rating nut. Is installed into the bottom of a wood stick pendulum by threading it into a pilot hole drilled into the wood.

PD15: $10.00
Clock Pendulum Nut

Lyre Rating Nut

This is the size rating nut for most of the Lyre pendulums for German units. Turn this nut as to move the pendulum bob UP will speed time up.

PD25: $10.00
Clock Pendulums

Shelf Clock Pendulum Nuts

Rating nuts are for antique ginger bread or kitchen style type clocks. Also for larger threaded rating rod diameters on floor clocks.

PD17: $15.00