Motor to Wheel - a Look at Belts, Chains and Drive Shafts
Posted by Ben Baker on Oct 24th 2016
| Chains and belts are the most common methods to get power from the engine on a motorcycle to a wheel. Some bikes do use drive shafts, but that is less common. Here's a look at these methods motorcycles use to get a ride down the road. |
|
WHICH CAME FIRST |
| Belts drove the first motorcycles. Heavy duty leather was mounted to a large pulley. Today, that sounds close to impossible, but early motorcycles were not the power plants we ride today. Some belts were made from reinforced rubber, but they were much less common. |
| "In the bad old days, these primitive systems were not much of a problem, since power output from the contemporary engines was, to say the least, modest. By about 1912, as engine output climbed, even those motorcycle manufacturers which had been using belts switched to chains, or - in a few cases - to shaft drive," said Motorcycle Daily. |
| As chains proved more durable, belts faded away. The renaissance came in the late 1970s as DuPont Kevlar made drive belts tougher and longer lasting. The Kevlar cords in the rubber reduced stretch, a key factor. Harley's FXB Sturgis, 1980, was the first huge mass market ride to incorporate belts in a long time. |
| Today's belts only look like the first drive belts on the surface. The old ones were smooth. Today's belts have "high-modulus rubber material" that makes the teeth on the belt. These match grooves on the drive pulley. This eliminates slip so provides a much better transfer of power. |
| Chains and shaft drive came after belts. Which was first depends on who is doing the research. Motorcycle craftsmen were experimenting with both at the same time. So why have chains traditionally dominated? RevZilla gives several reasons: |
|
|
|
| Shaft drive took a few more years to catch on. FN (Fabrique Nationale de Herstal) was a gun maker in Belgium which diversified. In 1902, it produced the FN300 with a shaft drive. FN made the shaft drive a serious contender in 1905 with the FN Four, an in-line four-cylinder ride with the shaft drive. |
|
MAINTENANCE |
| Change the oil, change the tires, but what about the belt, chain or shaft? What kind of maintenance is required? |
|
Chain |
| Today's drive chains are a bit different from the first chains. Those were little more than bicycle chains mounted to a motorcycle. Today's chains have sealed parts to keep the lubricating grease in the internal parts. However, they still require more maintenance than any other drive system. Chains can break. They can fling oil and grease everywhere. They also wear out the sprockets on the pulley over time, requiring both to be replaced regularly. |
| Belt |
| Belts are square in the middle for maintenance. Just like fan belts on a cage, they can wear out and over time they will stretch. With fan belts, this is less of a problem than on a bike. Bikes have pulleys with grooves for the belt teeth; too much stretch means the teeth and slots misalign. |
| When you get your tires replaced, have the belt checked. Cracks mean it's time to replace the belt. |
| Belts are not used on offroad bikes because grit and rocks can get kicked into the drive area and shred the belt. |
| Shaft |
| Hands down, the drive shaft is the king for low maintenance. "Drive shafts are nearly maintenance-free, impervious to the outside environment, and—barring any sort of freak failure—will last the life of the bike. All strong benefits, but shafts are also costly to build, heavy, and sap more power than other final-drive systems," says Ari Henning. |
|
WHICH IS BEST |
| Want to start an argument? As a bunch of bikers which is the best drive system, shaft, belt or chain. About the only place you'll find agreement is chains on offroad motorcycles for reasons above. |