Adjustment of Bicycle Derailleur

Adjustment of bicycle derailleur
1. Rear dial guide wheel: The function of the rear dial guide wheel is to fix and move the position of the chain, so that the chain can run stably in a certain gear or move the chain to a different gear. When we adjust the rear derailleur, we are actually adjusting the rear derailleur guide wheel.
2. Shift line: The movement of the rear derailleur pulley is determined by the retraction and release of the shift line. The adjustment of the transmission line directly determines the accuracy of the transmission, and is the most important and time-consuming task in adjusting the transmission.
3. Limit screw: The main function of the limit screw is to prevent the guide wheel from moving beyond its working range and causing the chain to drop. Except for the extreme two gears, there is no impact on shifting accuracy.
4. Tension screw: The function of the tension screw is to adjust the distance between the rear dial guide wheel and the sprocket of the flywheel.
Starting condition: The rear derailleur is installed and not yet cabled.
1. Adjust the H limit screw. After the rear derailleur is installed, the guide wheel is at a high position, so we took the screwdriver and screwed the limit screw directly to align the guide wheel with the smallest tooth.
2. Adjust the L limit screw. Push the derailleur to the low position by hand, hold it down, take the screwdriver and turn the L limit screw to align the guide wheel with the largest chainring. This step can be done after pulling the cable, but I personally prefer to adjust the two limit screws before pulling the cable.
3. Pull the wire. The cable is the fixed shift cable, very simple. Note that at this time the shift gear should be in the corresponding highest gear. When pulling the cable, the shifting cable adjustment knob must be screwed to the lowest position, otherwise the shifting cable will not be able to be taut, let alone adjusting the allowance.
4. Adjust the shift cable. Use the shift cable adjustment knob to adjust the shift cable so that the guide wheel can align with the corresponding gears in each gear. Not every derailleur has a derailleur adjustment knob, but in the entire transmission cable routing, there must be The existence of the transmission adjustment button, for example, some are on the dial, some are on the cable seat, and some are directly strung on the transmission line, etc.
5. Adjust the tension screw. Now install the chain, and then adjust the tension screw to keep a proper distance between the idler pulley and the sprocket. In the case of normal operation of the chain, the smaller the distance, the better. Generally speaking, 6mm is a limit value. Since the trajectory of the guide wheel cannot coincide with the radian of the flywheel, we only need to adjust the tension screw in the gear closest to the rear guide wheel and the flywheel. Visual inspection shows that the 1st gear, the rear guide wheel and the flywheel are far away. Recently, it is enough to adjust the tension screw in the 1st gear. Note that the combination of different rear derailleurs and cassettes will be different.
6. Fine-tune the shifting cable. Crank the crank, keep shifting, and fine-tune the shift knob until each gear shifts smoothly.