The topic of today's article is about setting up your bike. After all, there are a lot of different nodes in it, which requires close attention and regular maintenance. We will especially focus on Shimano products. Setting the rear gearshift has some nuances. If you have installed equipment of another manufacturer, then do not neglect the materials set forth in this article, since the principles of operation and debugging of all such products are common, because they have a similar design.
Principles of operation
The operation of the rear derailleur still seems to many cyclists a mystery over seven seals. After all, he can reliably and unpretentiously carry out his functions, but one fine day "heal his own life." If you do not have experience in eliminating such "independence", then this can be a significant problem, especially if such a malfunction falls like snow on his head, on the way. Therefore, usually beginner enthusiasts take their "iron friend" to the workshop, where an experienced specialist eliminates this problem within a few minutes. However, what operations he performed, what he regulated, lubricated or tightened, remains an unknown. Therefore, you need to be patient and understand the principles by which the Shimano rear gearshift functions. If you follow the recommendations below, you will not have difficulties with the further maintenance of your bike with your own hands. It is only important to study the necessary theoretical base and independently confirm it in practice.
Necessary tools
First of all, you may need:
- hex keys or their set (3- and 5-mm are required);
- Phillips screwdriver.
Before starting debugging, it is important to make sure that the mechanism is still functioning. At Shimano, the rear gearshift is set according to the manufacturer's recommendations, it is possible that you still have it if the chain tensioner was purchased separately. If the bike was purchased assembled, then usually these documents are not.
Survey
Try to visually diagnose the condition of the speed switch parts. After all, you can spend hours studying the theory and trying to repair, and in the end find out that the part can not be restored. To do this, stand behind the bicycle and try to make sure that the speed switch and its bracket (rooster) are on the same line and there are no noticeable distortions or significant deformations. The chain that connects these elements may help you a little, but it should also be in a satisfactory technical condition - well lubricated and with acceptable wear, since some difficulties when switching speeds can also arise due to its unsatisfactory functioning or the wrong type.
Similarly, with the gear shift cable - if it is rusty and constantly jamming in the casing, then there can be no talk of any reliability or usability. However, this situation is easier to fix, you just need to add the necessary amount of graphite lubricant to it, and, possibly, the adjustment of the Shimano rear derailleur will advance faster.
Important setup steps
In this activity, there are three key stages, neglect or violation of the sequence of their implementation can result in damaged equipment or its expensive repair. Therefore, it is necessary to carry them out only in this order: pull the gear shift cable, make sure the adjusting screws are in the correct position and adjust the tensioner itself.
Casing and steel cable
Adjusting this tool is very important, as the cable is responsible for how far the speed switch shifts when clicking the shifters. If the tension is excessive, the convenience of gear selection will become much more complicated, and sometimes the chain can jump to neighboring stars or very slowly shift to a lower gear. At the same time, if the effort is not enough, then nothing will happen when changing the position. Therefore, a properly tensioned cable can eliminate half of the difficulties that arise in Shimano Alivio systems . The rear derailleur often causes inconvenience due to structural features. After all, the middle-class line, to which this type of device belongs, is not intended for too intensive use, like a professional one, for example, Deore or its analogues.
Adjustment position
Changes that are designed to limit the displacement of the bicycle chain are made with special screws. Usually the top one is responsible for the shift that the rear derailleur (Shimano Tourney and other budget series) receives when the gear is increased, while the lower one is aimed at lowering. If the chain slips through the largest star, then it is the position of the gear adjustment when increasing them that needs to be changed. Similar actions are carried out at lower speeds. However, every lover needs to know that if the rear derailleur is bent and then leveled, it must be set up again, as it changes its position.
Tensioner and its adjustment
This adjusting screw is used very infrequently, since it helps to adjust the location of the upper pulley relative to the cassette along which the chain moves. If it is not twisted, then the above details can hurt each other and cause a lot of inconvenience. However, such a situation is very rare, since this unit is attached quite reliably and there is no backlash in it, which would contribute to its weakening.
At Shimano, setting the rear derailleur is very affordable, however it may seem too complicated for beginners. Although this mechanism has a simple design, its adjustment requires a scrupulous attitude and patience. Haste here is inappropriate, especially if the work is done for the first time.
Special cases and their resolution
If, when pedaling with little effort, the chain slips, then most likely it has stretched along its length and needs to be replaced. Using it in this form can harm not only the stars of the system, but also the cassette, which will render them unusable. A worn chain wrinkles their teeth or forms recesses on them, after which these gearshift elements cannot be used.
When changing speeds, it is necessary to ensure that the chain moves without distortions. Although its place is fixed, if you have a Shimano Deore rear derailleur installed or a class higher, but for people using more common attachments, these cases are not uncommon. This malfunction leads to accelerated wear of the system and circuit elements, therefore, it must be taken very seriously.
If the gear shift is suddenly broken and no longer works, then most likely there are difficulties with the cable. Either its breakage occurred, or it was not securely fixed with a fixing bolt.
If you have Shimano attachments installed whose rear derailleur has already been set up and does not function properly, you need to make sure that the cable in the shirt is free to move. If there are breaks or places with a braided winding, then it must be replaced. Similar problems can also occur if the bicycle cock has been bent.