Disc discs are the main component in a motorcycle braking system that functions to convert kinetic energy into heat energy through friction. The geometric design of the disc, including the diameter and number of holes, affects the effectiveness of braking as well as the heat dissipation ability. This study aims to analyze the effect of variations in diameter and number of holes on disc discs on braking distance and disc temperature. The research method used was an experimental method with three variations in disc diameter (190 mm, 220 mm, and 260 mm) and three variations in the number of holes (30, 36, and 42 holes). The test was carried out through a controlled braking procedure at an initial speed of 40 km/h on flat road surfaces with stable weather conditions. Braking distance data is measured using ultrasonic sensors, while disc temperature is recorded with a high-accuracy infrared thermometer. The results showed that the diameter of the disc disc had the most significant influence on the braking distance. The larger the diameter, the greater the braking moment resulting so that the stopping distance becomes shorter. The number of holes in the disc also plays a role in heat dissipation because the holes enlarge the heat dissipation area. However, the increase in the number of holes tends to slightly increase the braking distance due to a reduction in the area of frictional contact field. The most optimal configuration is found on a 260 mm diameter disc with 42 holes, which results in the shortest braking distance of 8.25 meters and the lowest temperature rise of 4.47°C.  Statistical analysis using Two-Way ANOVA confirmed that the diameter and number of holes had a significant effect individually, but there was no significant interaction between the two. These findings confirm that the selection of the right disc dimensions is critical to improving braking performance, thermal efficiency, and rider safety.

The global demand for energy, particularly fuel oil, continues to increase along with the growth in the number of vehicles and industrial activity. However, limited fossil fuel reserves and the environmental impacts of their use have prompted various studies to find alternative fuels that are more environmentally friendly, efficient, and sustainable. In this context, ethanol and xylene have emerged as two potential fuel additive candidates. Ethanol is known as a biofuel derived from renewable sources and has a high octane rating and oxygen content that can support a more complete combustion process. On the other hand, xylene is an aromatic compound with a high octane rating that can improve combustion stability and reduce the risk of knocking or detonation in engines. This study aims to evaluate the effect of ethanol and xylene additions on the flame characteristics of Pertamax fuel, particularly in terms of flame duration and height. Through a laboratory experimental approach, observations were made on the combustion process of pure Pertamax and several fuel blends with varying ethanol and xylene contents. The results showed that pure Pertamax produced a flame with an average duration of 0.734 seconds and a flame height of 4.5 cm, while one of the best blends, namely the fourth blend containing ethanol and xylene, produced a flame duration of 1.084 seconds and a flame height of 5.7 cm. These findings indicate that the addition of ethanol and xylene can significantly improve combustion performance. These results not only enrich knowledge regarding the combustion characteristics of blended fuels, but also open up opportunities for the development of alternative fuel formulations that are more environmentally friendly, energy efficient, and support reducing dependence on fossil fuels in the future.

Automatic transmission motorcycles, especially those with 110cc engines, are increasingly in demand by the public because of their practicality. The performance of this motorcycle is greatly influenced by the transmission system, especially the Drive pulley and Roller components. The correct setting of the Drive pulley angle and Roller mass can improve engine performance and reduce noise, thus supporting driving comfort. This study aims to analyze the effect of variations in the Drive pulley angle and Roller mass on engine performance, in terms of power (HP), torque (Nm), and noise level (dB) at several engine speeds. The variations tested include the Drive pulley angle of 13.5°–14° and the Roller mass of 13–15 grams, with testing at 5000, 6000, 7000, and 8000 RPM. The test results show that the combination of the angle and Roller mass affects engine performance. At 5000 RPM, the combination of the 14° angle and 15 gram Roller produces the highest power, torque, and noise. At 6000 RPM, the combination of 13.8° and 13 grams produces a maximum power of 6.86 HP and 8.15 Nm of torque, with a noise of 97.40 dB. While at 7000–8000 RPM, the combination of 13.5° and 15 grams provides the best performance with 7.10 HP and 6.30 Nm of torque, accompanied by a noise of 104.17 dB. In general, increasing the angle and mass of the Roller increases performance, but is followed by an increase in noise.

The braking system is a crucial component that affects driving safety on motor vehicles, especially motorcycles. The purpose of this study was to determine how brake fluid viscosity and brake fluid pressure affect braking distance. Brake fluids A (12,001 cSt), B (11,120 cSt), and C (10,958 cSt) are three types of brake fluids that vary, along with brake fluid pressure, which ranges from 1.5 to 4.5 bar. A 7 mm bolt that is 70 mm long and drilled into the brake lever is used to limit the pressure. Based on the results of the study, braking distance is affected by fluid pressure and viscosity. With the same fluid pressure of 4.5 bar, brake fluid A is able to brake at the farthest distance of 25.01 meters, brake fluid B is able to brake at the middle distance of 23.12 meters, and brake fluid C is able to brake at the shortest distance of 21.79 meters.

Internal combustion engines generate thermal energy through the combustion of an air-fuel mixture. The incoming air must be filtered, as it contains impurities and particles. While air filters are commonly made from paper, they can also be developed using organic waste materials such as sugarcane bagasse and rice husk. This study aims to analyze the effect of biocomposite air filters on engine power, torque, and specific fuel consumption (SFC), by varying the material composition and the number of pleats, and comparing the results with those of a standard air filter. The method used is a quantitative experimental approach involving dyno testing on a 150 cc motorcycle engine. The tested material compositions include 50:50, 40:60, 30:70, 60:40, and 70:30 (sugarcane bagasse\:rice husk), with pleat counts of 28, 26, and 24. Results showed that the biocomposite filter with 28 pleats and a 30:70 composition delivered the best performance, producing 18.47 Hp and 16.66 Nm of torque—higher than the standard filter’s 17.98 Hp and 15.52 Nm. In terms of fuel efficiency, the 26-pleat filter with a 50:50 composition recorded the lowest SFC at 41.90 g/kWh, significantly better than the standard filter’s 53.03 g/kWh. Conversely, the 60:40 composition resulted in the highest SFC due to increased airflow resistance.

The development of the automotive industry is now experiencing a very rapid increase in the type of motorcycle. One of them is a motorcycle with automatic transmission or automatic motorcycle or CVT (Continously Variable Transmission). Matic motorcycle users often experience a lack of performance when used on daily trips. The mass of CVT rollers and springs is the main factor in the lack of performance of the matic motorcycle which is less efficient for its users. This research was conducted to determine the effect of increasing power and torque on motorcycles that are now declining in performance.
The method used in this research is experimentation. Tests were carried out using a dynamometer tool to determine the comparison of the results of the variables carried out and compared to obtain maximum power and torque. The data obtained will be analyzed using statistical methods to evaluate the relationship between changes in roller mass and spring constant to power and torque.
The results showed that the maximum power generated was at a roller variation of 11 grams and a spring constant of 33.78 N/cm of 7.19 HP at 6500 rpm engine speed. While the maximum torque is generated from the variation of roller 13 grams and spring 28.83 N / cm of 8.00 Nm at 6000 rpm engine speed.