If your motorcycle's final drive mechanism uses a chain or belt, you're probably asking yourself all sorts of questions. When is it time to replace the chain/belt? How do I make adjustments? Can I use non-factory parts?

(In the case of a chain-driven motorcycle, you need to know the exact amount of power transferred to the rear wheel.)

Before you go out and purchase your next motorcycle, here's some useful information about the final drive of any motorcycle. This system sends power from the engine to the rear wheel through a clutch and transmission. A steel shaft at the end of the latter represents the last link between the gear and the chain or toothed belt.

The term "final drive" designates the set of gears (or sprockets) that are driven by the chain or belt. Drive shafts are another method used to move mechanical power around, especially on touring motorcycles. While these often prove more durable, they require regular maintenance.


Chains
Made from a specific number of links, chains are widely used in today's motorcycle industry. Basically, the power is conveyed by a roller chain passing over a sprocket gear, with the teeth of the gear meshing with the holes in the links of the chain. The gear is turned, and this pulls the chain putting mechanical force into the system.

Obviously, chains have strengths and weaknesses. Their main quality is simplicity. They can be dismantled in a flash to replace any defective link, for example by adding a quick-release link. All you need here is a set of long-nose pliers. However, it's important to remember that these links can only be mounted in one direction. Also, don't forget the outer clip, which must always be mounted so that its opening is pointed against the rotating movement of the chain. Otherwise, the link is prone to be ejected as soon as you accelerate hard with your motorcycle.

Other chains use permanent, riveted links, making them inconvenient for emergency repairs. This time, you don't have a choice but to use a chain tool. These links are usually recommended for high-performance chains; quick-release links should be avoided here as they are not strong enough to withstand heavy loads. You can reinforce them, although this procedure is not recommended by chain manufacturers.

In the 1970s, I developed my own little system. Once, while one of our team riders was leading an enduro race, his chain broke just a few hundred feet from the finish line. I used my imagination to the fullest and came up with the idea to tweak the pull-tab of a Coca-Cola can. I cut a thin strip measuring 5x15 millimeters and placed it behind the clip. Then, I folded the extremities onto the outer edges of the clip and added a drop of silicon. Good thing at the time because it allowed our guy to maintain his lead in the Quebec Motocross Championship rankings.


Photo Credit : Henri Lebarbé