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# What are different Grandfather Clock Pendulum options?

*   [Knowledge Base](https://www.clockworks.com)
*   Grandfather Clock Pendulum Information

### Article sections

## Grandfather Clock Pendulum Information

[Grandfather clock pendulum](/clock-parts/german-mechanical-clock-pendulums.html") information begins with the obvious discussion of length. The length of the [pendulum](https://www.clockworks.com/product/wood-stick-pendulum-for-hermle-clocks) on [German units](https://www.clockworks.com/clock-movement.html) comes in a few CM options. [German units](https://www.clockworks.com/clock-movement.html) measure the [pendulum](/product/kieninger-lyre-clock-pendulum") from the top of the [movement](/clock-movement/hermle-clock-movement.html") to the bottom of the nut threads. The [pendulum](/product/hermle-lyre-pendulum") itself, the [leader](https://www.clockworks.com/product/clock-pendulum-leader) it hangs on, and the [suspension spring](https://www.clockworks.com/product/clock-pendulum-suspension-spring-hanger) that the [leader](https://www.clockworks.com/product/clock-pendulum-leader) hangs on. All three components in [centimeters](https://en.wikipedia.org/wiki/Centimetre) make up that CM length in the drop down menu.

### Pendulum length information

To know how long the actual [pendulum](/product/kieninger-lyre-clock-pendulum") is, subtract 15CM from the options with the [pendulum](/product/kieninger-lyre-clock-pendulum") length. This will exclude the [leader](https://www.clockworks.com/product/clock-pendulum-leader) and [suspension spring](https://www.clockworks.com/product/clock-pendulum-suspension-spring-hanger), and be the actual [pendulum](/product/hermle-brass-rod-clock-pendulum") length from tip to tip off of the clock. This length can vary as if a larger [pendulum](/product/kieninger-lyre-clock-pendulum") bob is selected, the actual length of the [pendulum](/product/wood-stick-pendulum-for-hermle-clocks") gets longer. Why the CM length matters at all is because if the [pendulum](/product/kieninger-lyre-clock-pendulum") length is not near the CM length of the movement, the clock will not keep time. So the gearing in the movement and the [pendulum](/product/kieninger-lyre-clock-pendulum") length works together to keep time around the specified CM length.

### The bob width Options

A Lyre grandfather clock [pendulum](https://www.clockworks.com/product/hermle-lyre-pendulum) comes with either a 6 1/2, 8 1/2, or 10 1/2 inch bob diameters. The 'Bob' is the round disk at the bottom of the [pendulum](https://www.clockworks.com/product/hermle-lyre-pendulum) . Moreover, the CM length on the movement will indicate the length of the [pendulum](/product/kieninger-lyre-clock-pendulum") from the TOP of the movement all the way down to the bottom of the pendulum nut threads. This is an approximate length that depends on other factors such as bob diameter and weight of the [pendulum](https://www.clockworks.com/product/uw-urgos-stick-clock-pendulum). Basically if the CM is 94CM the [pendulum](https://www.clockworks.com/product/wood-stick-pendulum-for-hermle-clocks) itself will be about 35 inches tip to tip off of the clock, and the 114CM option would put this same measurement at approximately 44 inches.

Last Updated: 2 months ago in

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