Apart from bicycles and motorcycles, there are several other machines and devices that still use chains as a primary means of power transmission. Here are a few examples:

1. Chainsaws: Chainsaws commonly use a chain and guide bar system to cut through wood. The chain is driven by a motor and rotates around the guide bar, enabling efficient cutting.
2. Industrial Machinery: In various industrial settings, chains are used to transfer power and motion between different components and machinery. For example, chain drives are used in conveyor systems, printing presses, packaging equipment, and manufacturing machinery.
3. Agricultural Machinery: Chains are commonly used in agricultural equipment such as combines, harvesters, and tractors. They are employed for power transmission in applications like driving the wheels, belts, or other components.
4. Garage Door Openers: Many residential and commercial garage door openers use chains to move the door along a track. The chain is driven by a motor, allowing for easy opening and closing of the garage door.
5. Lifting and Hoisting Equipment: Chain hoists and cranes often rely on chains to lift and move heavy loads. These chains are typically designed to withstand high loads and provide reliable lifting capabilities.
6. Mechanical Watches: Traditional mechanical watches often utilize a chain or metal link system known as a “watch chain” or “watch strap” to connect the watch case to the wrist. This chain allows for secure attachment and comfortable wear.
7. Marine Applications: Chains are extensively used in marine applications, such as anchor chains, mooring chains, and marine propulsion systems. They provide strength and durability necessary for marine environments.

It’s important to note that while chains are still used in various machines, technological advancements have led to the development of alternative power transmission systems like gears, belts, and electronic systems in many modern applications. The choice of power transmission method depends on factors such as efficiency, durability, noise levels, and specific requirements of the machine or device.