In some cases, you still need to loosen the front derailleur adjusting screw to improve gear shifting to a small sprocket. Because of this, the chain begins to jump off the sprocket, to prevent this, you can install a special device. a limiter. It attaches to the seat tube of the frame and physically prevents the chain from jumping off the system.
How switches work
Most modern bicycles use derailleurs. Gear shifting is carried out by throwing the chain from one sprocket to another. The derailleurs seem complicated, but they are actually very simple and work exclusively with brute force, especially the front derailleurs. The front derailleur is just a metal frame that can be moved back and forth from side to side. Older switches were a frame fixed on one axis, while modern switches use a parallelogram for this.
The front derailleur works by pushing the chain sideways, causing the chain to run at an angle to the star rather than in a straight line. When this angle becomes too sharp, the chain can no longer hold on to this sprocket and jumps off to the next smaller one. When the chain changes from a smaller sprocket to a larger sprocket, the changeover is slightly different. The chain pushes towards the larger star. adjacent to the one you are riding on and rubs against its side. Ultimately, it is captured by the tooth of the larger star, pulled up and to the side. it moves to this star. Modern stars often have specially shaped sides. sloping surfaces and pins that grab the chain for better shifting. The front derailleur tosses the top of the chain, the rear derailleurs the bottom. The upper part of the chain transfers the pedaling force to the rear sprockets, so if you pedal with more force, the chains are harder to bend laterally due to the tension. This is why it is important to reduce the effort when shifting the front derailleur. But this is not so important when shifting with the rear derailleur, as it uses the lower, loose part of the chain. There are a number of challenges when choosing a front derailleur versus a rear derailleur:
Sometimes it is possible when one setting of the limiter can cause a slight fall of the chain from a small sprocket, and a little more tight. prevent switching to this gear.
In such cases, a good, but rough, solution is to install special devices.
How to install the front derailleur on a bike yourself
The front derailer is installed according to the following algorithm:
- Secure your bike to a stand. This will greatly simplify the work;
- Before installation, you must make sure that the mechanism is thoroughly washed, and the rubbing components are properly lubricated;
- Fasten the bike chain: at the front at the minimum sprocket, and at the rear at the maximum;
- Loosen the cable adjusting screw;
- Slide the front derailleur clamp onto the seat tube;
- Install the cable on the derailleur and tighten it;
- Check the position of the frame when operating the gear selector. If there is a distortion, too large or small interval between the sprocket and the frames, the mechanism must be removed and reinstalled on the seat tube again;
- Tighten the fixing screw.
Features of setting the bike‘s front derailleur
The front derailer of the bike is set up after mounting or reinstallation. Get a set of fine-pitch wrenches and a slotted screwdriver. Follow the steps in this order:
- Align the mechanisms so that the transfer frame and the drive sprocket are parallel to each other;
- Turn the low gear stop screw so that the clearance between the bike chain and the frame is minimal;
- Secure the front derailleur cable with a screw or nut;
- Secure the bike chain to the sprockets: at the front at the maximum, at the rear at the minimum. Then, adjust the high gear stop screw on the frame to keep the distance between the frame and the bike chain as close as possible. They should not touch each other;
- Check the operation of the device while driving. The front derailleur is set correctly if the steel frame and chain do not rub against each other. Now you can read: the setup is over.
How to adjust the speed switch on a bike
It often happens that either the speeds on the bike are not switched clearly, or some new transmission elements have been installed. In this case, you will need to adjust the speed switch and it is quite possible to do this work on your own, without contacting specialized workshops.
What to do if you can’t adjust the bike’s rear derailleur
There are several methods for solving this issue. But if the standard tuning instruction did not work, to tune the rear derailleur you need to:
- dismantle the chain, remove the cable;
- move the switch to the chain position to the smallest star;
- use adjusting bolts (this way you can tighten the cable);
- set the adjusting bolt H to the extreme position;
- move the part called the parallelogram to the big star and adjust the position of the bolt L.
The regulator is fixed with bolts. It must be set to the extreme position. After that, the chain must be displaced in this order: the front cassette is the largest star in diameter, the rear one, on the contrary, is the smallest.
How to install a Front Derailleur
How to properly adjust the rear derailleur
To independently adjust the rear derailleur on a bicycle, you just need to strictly follow the step-by-step instructions from specialists in this process. So, follow all the steps:
- Move the chain to the small sprocket with the right shifter.
- Unscrew the fixing screw and release the cable.
- Find the screw marked “H”. Use a screwdriver to adjust this screw so that the smallest star lies in the same plane with the rollers, which are located in the foot (frame).
- Pull the cable by hand and fix it with the screw.
- Check the operation of the switch, and if it does not work correctly, the chain does not switch well to large stars, then you need to tighten the cable harder (either with the help of a drum or with a switch).
- Move the chain to the largest sprocket available in the cassette.
- Find the screw marked “L” and adjust it so that the tab (frame) and the sprocket are in the same plane. in this case, the crossover will not be able to get into the spokes of the front wheel.
How to fix defects
The speed switch will work perfectly and the bike itself will be with a new (or not very old) cable, with absolutely intact shirts (and not dry!) And not deformed (or in a small volume) stars and chain.
If the cable is just stretched, then you just need to pull it up. But if the cable breaks, then you cannot do without replacing this element. The process of replacing the cable is not difficult, the main thing is to strictly adhere to the recommendations of the specialists:
How to Install a Front Derailleur
- unscrew the cable fixing screw, which is located on the cross-over;
- pull the cable out of the shirts;
- if necessary, disassemble the shifter and pull the cable out of it;
- a new cable must be inserted into a special groove in the shifter, and it is the metal tip of the cable that must enter into the groove;
- lubricate the entire cable with a special grease, you do not need to spare the consumable;
- pass the cable through the shirts;
- there are special grooves on the frame, into which shirts are tucked;
- fasten the cable with a screw on the front end.
In case of poor gear shifting, pay attention to the return spring. it must be clean and lubricated. To achieve this, you just need to rinse the spring under running water, dry it completely and lubricate it thoroughly.
If the frame of the rear derailleur is crooked, then this can only mean one thing. the cock is bent. If this is not critical, then you can correct the cock with your hands. you need to take the rear switch in your hand, which is fixed on the cock, and hold the frame with the other hand. Slowly pull out the problematic transmission element (cock) until relatively even setting.
Note: this “repair” of the cock is a temporary solution to the problem of shifting gears. The fact is that the rooster is a consumable that needs to be changed in time, and not constantly repaired / pulled.
In some cases, the bike owner pays attention to a deformed rear derailleur (the front derailleur rarely suffers on impact). it can also be returned to its original position with the help of hands. But if the rear derailleur is deformed too much, then it is advisable to replace it.
Note: After performing specific manipulations to repair bent / deformed parts, you should not use the bike for too long. this may end in a fall, another breakdown at the most inopportune moments. And in some cases, such carelessness can lead to a traffic accident.!
How to install a rear derailleur on a bike?
Having clocked many kilometers on a bicycle, I was convinced that a branded derailleur is much more important for a comfortable ride than stylish grips or leather Brooks. But it’s not enough just to buy Shimano or Sram, the quality of installation and setup is important.