ZT 5-Speed Gearbox Reinforced Version 2019 The continuous development of Simson tuning engines (with increasing displacement) leads to ever higher performance values and thus higher torque. Especially with engines of 85cc and more, the standard 5-speed gearboxes reach their limits, with the first two gears being particularly at risk. With the new version, we can offer a significantly more robust variant, which at the same time allows for better acceleration due to the adjusted gear ratio of the 1st and 2nd gears. The gear jumps between the first 3 gears are much tighter, meaning that the engine does not rev down too much after shifting, thus more power is available in the next gear. The gear widths of the 1st and 2nd gear are almost the same as those of the 4-speed gearbox, and together with the adjusted gear ratio and optimized profile shifting, we can even achieve a higher load capacity than the 4-speed gearbox. Therefore, the new version is suitable for both extremely powerful street engines and high-revving racing engines, where gear connection is particularly important. The improvements at a glance: Medium first gear with wide gearing and optimized profile shifting Second gear with wide gearing, adjusted ratio (shorter) and optimized profile shifting Hardened thrust washers, as well as high-strength and hardened balls Reinforced shift fork with high strength and optimized geometry Output shaft with 6 detent balls for more precise shifting No modification of the engine housing necessary The gear ratio has been adjusted as follows. 1st Gear 10:43 2nd Gear 15:39 3rd Gear 19:36 4th Gear 22:34 5th Gear 24:32 Long 1st Gear or Medium 1st Gear? The choice of the right gearbox depends on the intended use and the respective engine. For maximum riding comfort (also with a passenger) for engines under 13Nm, we recommend the "medium" 1st gear, as here starting is facilitated by the shorter ratio. For extreme loads in motorsport / cross use, we still recommend the long 1st gear, because the 2nd gear is even more massively designed and the ratio allows for a better gear connection. For engines with 15Nm torque and above, we generally recommend the long first gear.