Clock Pendulum Leaders
Assorted leaders for post 1950 mechanical pendulum clocks of German origin. These fit German mechanical clocks made by companies such as Hermle, Kieininger, Jauch and Urgos.
Clock Pendulum Leaders
Mechanical pendulum clock leaders for post 1950 movements. These leaders will fit clock movements made in Germany after WW2. To get a replacement for a lost leader the first step is to visually match one. Check to see if the leader requires a double hook top, or a hole top, for it to mount to the suspension spring. Do the same on the bottom side. What is the required mount style for the pendulum to hang on the clock? Now the middle section, what one will engage with the swinging crutch on the back of the movement?l
The length of the leader
If the leader is missing there are some more steps to figuring 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, the leader comes only in two lengths. Grandfather clocks by Kieninger take the 7 inch leader, wall and mantle units take the shorter of the two. Hermle leaders are more involved when it comes to figuring out what length it should be.
Hermle leader lengths
A Hermle floor and wall clocks will always take leader D or G. Leader E is for a low bridge to a high bridge conversion on a Hermle grandmother clock. Unless changing the movement from LB to HB this one can be eliminated from the possibilities. Leader F is for mantle clocks and also to create a custom pendulum length. 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.
Leader F for Hermle mantle
Mantle clocks with a Hermle clock movement will take leader F, usually. In a situation where the leader is missing and the length is unknown this is how to get the right length. Use the CM number off of the back of the movement. This CM length is the pendulum length from the top of the movement and all the way down to the bottom of the pendulum. Take this CM and divide by 2.54 to get the inch equivalent. Subtract the length of the pendulum and the suspension spring length from this measurement. What is left is the length of the pendulum leader F that’s needed for the Hermle mantle clock. There are 1 1/2 inches of thread at the bottom of the pendulum for fine adjustment. With all this adjustment room at the bottom of the pendulum this measurement does not have to be exact.
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. 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 and all the way down. Based on the smallest bob diameter and is longer for a wider pendulum bob. If the clock pendulum length is too long it will slow timekeeping. If the pendulum is too short the time will go too fast on the clock. The wrong length leader will create timekeeping to be off.This may or may not be corrected by raising the bob up or down with its rating nut below the bob. When timekeeping is not able to be regulated with this method it may need a different length pendulum leader.