While it is true that most motorcycles have sequential transmissions, where the gears are arranged in a specific order, the shift pattern can vary between different motorcycles. The reason for this lies in the design choices made by motorcycle manufacturers and the intended use of the motorcycle. Here are a few factors that contribute to the variation in shift patterns:
Tradition and Preference: Different motorcycle manufacturers may have their own preferences or traditions when it comes to the placement of the shift pattern. For example, some manufacturers may choose a one-down, four-up pattern (first gear is down, and the rest are upshifts), while others may opt for a one-up, four-down pattern. These choices are often influenced by historical design practices and rider preferences.
Ergonomics and Riding Style: The shift pattern can be influenced by the ergonomic considerations of a particular motorcycle model. The manufacturer may place the shift lever in a position that is most comfortable and convenient for the rider, depending on factors like foot position, riding stance, and intended use of the motorcycle. Sport bikes, for instance, may have a shift pattern that allows for quick upshifts while keeping the rider's foot in an optimal position on the footpeg.
Gearbox Design and Configuration: The internal design and configuration of the gearbox also play a role in determining the shift pattern. Manufacturers may adopt different gearbox designs, such as constant mesh or dog engagement, which can affect the placement of gears and subsequently the shift pattern.
Regional Market Differences: Shift patterns can sometimes vary based on regional market preferences and regulations. In certain countries, there may be legal requirements or cultural norms that influence the shift pattern chosen by manufacturers. For example, in some countries, the standard shift pattern may be reversed, with first gear being upshift and the remaining gears being downshifts.
It's important to note that while the shift pattern may vary, the basic sequential transmission system, which enables the rider to move through the gears in a specific order, remains consistent across motorcycles.