Gear Train
The gear train is the series of meshed wheels that carries energy from the mainspring barrel to the escapement. Along the way it steps the power down and the speed up, so the hour, minute and seconds hands turn at the correct rate. Because it keeps the watch going, it is also called the going train.
At a glance
- Job
- Carries energy from barrel to escapement
- Effect
- Steps power down, speed up
- Also called
- Going train
Inside a mechanical watch, energy begins at a single source and flows in one direction. The gear train is the transmission line that carries that energy from store to point of use, turning the slow, powerful rotation of the barrel into the fast, regulated motion that drives the hands.
The path of the energy
Power is stored in the mainspring barrel and steps through a chain of meshed wheels. At each pair the ratio of teeth resets both speed and force:
- Centre wheel: carries the minute hand and sets the one-turn-per-hour rhythm
- Third and fourth wheels: speed the rotation up to produce the seconds-hand pace
- Escape wheel: the final link, handing the energy to the escapement
Why it is called the going train
Because these wheels keep the watch running continuously, they are known collectively as the going train, which sets them apart from added wheel sets, such as a chronograph's, that turn only on demand. You can explore the wider family in the Movement category, and find affordable mechanical examples in our Best Japanese Watches guide.
Examples
In an affordable automatic, the gear train is the working core of the movement, carrying energy from the barrel to the escapement in measured steps to drive the hands.
View this watch
Comparison
The going train and added wheel sets do different jobs.
| Option A | Option B | Notes |
|---|---|---|
| Going train | Chronograph train | The going train turns continuously whenever the watch runs; chronograph wheels engage only when you press the pusher. |
Related terms
Watches that show this
Frequently asked questions
Are the gear train and going train the same thing?
Yes, in most contexts they mean the same thing. The wheels that carry energy from the barrel to the escapement and keep the watch running continuously are the going train. Added wheel sets that run only on demand, such as a chronograph's, fall outside that term.
Why does the gear train step the power down and the speed up?
The barrel turns slowly but with great force, while the escapement needs a fast, steady feed. The ratio of teeth between meshed wheels raises the speed and lowers the force at each step, so the seconds hand ends up turning at the correct pace.