The teeth or ridges on a driveshaft are referred to as splines. The splined driveshaft connects and transfers torque to a mating component of the drive train that cannot directly connect. This is either due to distance, or the need for relative movement between the two parts. These splined parts are produced by spline cutters that manufacture parts for a variety of industries. Apart from automobiles, a common application that splines can be found on is bicycles.
There is a plethora of people who ride bikes in my town, especially now since its summer time. Being in/near a city, most people who ride around do so in the road. Until recently, this was my main deterrent for riding my bike around town. I was afraid of getting hit by cars and felt bad for the ones who were stuck behind me. However, after getting trapped being numerous cyclists while driving, I realized it is not a big deal. This warranted me joining my roommates on biking excursions.
With splines, many of the residents around the area would be stripped of a favored pastime. Splines can be found on the cogset, crank set and bottom bracket of most bikes. There are two varieties of cogsets on bikes; cassettes and freewheels. Freewheels have a series of splines on its outboard end. It’s tightened onto the hub with the force from pedaling and remains there due to the ratcheting mechanism. Cassettes are a relatively recent invention. They have a series of straight splines that connect the device to the larger, splined sprockets.
The crankset consists of one or more sprockets and is what converts the motion made by the rider’s leg into rotational motion used in the drive train. The splined bottom bracket is contained within the crankset. It is what allows the crankset to rotate, converting the motion made by the riders leg into rotational. There are a number of different standards used for this bracket retaining to the number of teeth but they all perform the same basic function.