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In a transmission, the gear shift system is a part of extreme importance, being the responsible for controlling how and when the gear shifts occur. In sequential gear shifting systems, there are many design options that can be used for the development of such systems, but one of the most commonly used, due its simple implementation, is through a shift drum. However, due to the constant pursuit for optimization required by the market, even highly reliable systems must always be studied in order to obtain more efficient solutions, either by reducing costs, improving performance or making the system better adapted to the application. In order to do so, it is necessary to know the loads that are acting on the components in order to properly design the system for the application. This paper presents a simple test procedure in order to determine the loads acting on a sequential gear shift system applied to small motorcycles.

For intricate automotive systems that enclose several components, such as gearboxes, an important aspect of the design is defining the correct assembly parameters. A proper assembly can ensure optimized operating conditions and therefore the components can achieve a longer life. In the case of the support bearings applied to front-axle lightweight differentials, the assembly preload is a major aspect for an adequate performance of the system. During the design phase it is imperative to define reference values to this preload, so the application would endure its requirements. However, with the assistance of computer simulations, it is possible to determine an optimum condition of operation, i.e. optimum pre-load, which would increase the system reliability.

At this time, each major automotive market bares its own standards and test procedures to regulate the vehicle green house gases emissions and, thus, fuel consumption. Hence, much are the ways to evaluate the overall efficiency of motor vehicles. The majority of such standards rely on dynamometer cycle tests that appraise only the vehicle as a whole, but fail to assess emissions for each component or sub-system. Once the amount of work generated by the power source of an ICE vehicle to overcome the driving resistance forces is proportional to the energy contained in the required amount of fuel, the power path of the vehicle can be straightforwardly modeled as a set of mechanical systems, and each sub-system evaluated for its share on the total fuel consumption and green house gases emission. This procedure enables the estimation of efficiency gains on the system due to improvement of particular elements on the vehicle's driveline.