You will need
- chain bike;
- tool for disassembly of chain links;
- - additional teeth (if necessary);
- pin - connecting chain link
Determine desired length of chain always take into account not only the design of the bike, but the frame geometry and dimensions of sprockets and cassettes. In most cases you can simply compare the new with the old chain and shorten (lengthen) it to the correct size, putting or removing unnecessary links.
If the bike decided to install a new sprocket to set the desired number of links in the described way does not work. To determine the required length of the chain to install it on the biggest sprocket and pull it, removing the rear shifter in the full forward position.
Measure the desired length of chain in the wearing position, add to it 2 link. Please note that mounting bikes when sizing circuit rear shock definitely set in a position in which the tape as removed from the system switching speeds. Pass the chain through the foot of the tensioner is not necessary.
In addition, to determine the length of the chain can be and setting it to a larger front and smaller rear sprocket. At the same time with the rear derailleur pull links so that its frame was directed strictly downwards, i.e. the line connecting the centers of the rollers, the tensioner was vertical.
For road bikes, equipped with Shimano, the manufacturer recommends to determine the length of the chain, pulling it on the smallest sprocket. At the optimum length of the tensioner should not have any binding when you move.
Often there are recommendations to shorten the chain on a 1-2 level, if the rear switch has a short frame. Be very careful following this advice. A chance to make a mistake with this shortening there is always, and a possible damage to the chain and switch speed when switching to the big stars.
Usually on a road or hybrid bike used chain length 114-116 links or less. On the mountain – length: 106-108 units or a little more.
Advice 2: How to shorten a bike chain
Fine dust falling into the chain, which is under load during the movement leads to wear of the pins (axles), connecting links and, as a consequence, to the lengthening of the chain. After a long period of operation the chain can SAG and slide on the sprocket. To prevent this from happening, the chain shortened by removing unnecessary links.
You will need
- - squeeze for Bicycle chain;
- - pliers.
Disconnect circuit. To do this, set the squeeze on the chain link so that the stem pomace is located exactly opposite the pin. Rotation of the knob enter the stock in contact with the pin. Check their alignment.
Rotate the crank with a force sufficient to pin budged. Carefully vypressovyvaniem him up until his face will not be at a distance of 0.3-0.5 mm from the inner surface of the opposite cheeks (just to speak of it).
Remove the squeeze from the chain, exerting enough pressure. If necessary, use pliers with narrow sponges to disconnect the circuit.
Determine the number of units that can be removed. To do this, skip the chainbypassing the rear derailleur speed through the front and rear large sprocket. Placing one end of the chain on top of the other, determine the number of links that can be removed without losing connectivity of the circuit.
Remove unnecessary links. When you remove links, use the squeeze acting in this manner. The only difference between the operations is that in this case the pin can be pressed fully.
Connect circuit. When connecting the chain, place it so that the pin in the cheek, was sent in your direction. Swipe one end of the chain through the rear and front shifters and connect the ends by inserting a narrow polozone between the cheeks wide. The pin must match the hole in the hub a little bit and enter into it because it protrudes above the inner surface of the cheeks.
If it takes slightly unclench the cheeks, use a pair of pliers. When the ends of the chain will fall into place, the protruding pin should not allow chain to be separated. However, if there is a need to support the ends of the chain in the assembled position, ask someone to help you.
Press the pin into the hole. Insert the squeeze on the connecting link so that the axis of its stem exactly coincided with the axis of the pin. Rotating the driver tool, press a pin into the hole. Check the symmetry of its position in relation to the cheeks of the link. If necessary, adjust it to fit. Check the movement of the links in the connection. If it is broken, design the joint using the pliers.
When disconnecting the circuit, try not to push the pin completely, otherwise it will be difficult to get it back.
If you are not sure that the chain was stretched enough to be able to remove links before disassembling the chain will determine its actual length and compare with the nominal value. The length of the new chain can be determined from the value of step is equal to 25.4 mm, and the number of links. Chain length in service, is installed with devices for determining the deterioration of circuits that can measure the percentage of elongation.
Advice 3: How to determine the size bike frame
It is very important to pick the right size frame bike, as it will depend not only on the comfort and ease while driving, but also safety. An additional complication is the distinction designations from the manufacturers – size of frame may be indicated in inches ("), centimeters (cm) and standard units (XS, S, M, L, XL).
You will need
- - the tape or the tape;
- - table size;
- - a Bicycle.
Mountain or city bike pick up, given his height according to table. If your height was on the border of the two recommended sizes, note whether the designed suspension seatpost. Because it is not possible to lower the saddle until the end, if any choose bike smaller.
For traveling long distances buy road bike, it has a high top tube. When choosing frames, keep in mind apart from growth, the size of the top and seat tube. Stand next to the bike – the distance between groin and top tube should be at least 5-8 cm (this is especially important for men).
When choosing a children's bike, consider not only growth, but also age (though, if your child is growing faster than average rates, choose a bike larger). It is very convenient to use a Bicycle with adjustable saddle height and steering – in this case, the technique will serve not one year. Pay attention to the shape of your frame will be located below than the upper pipe, the safer it will be riding, as the child can jump from the saddle in case of loss of control.
For active and extreme skiing choose a frame smaller than for a quiet ride on a flat road because the bike will be more nimble and manageable.
If you are a slim build, take a bike with a big bike, for a full better to choose the technique on the smaller size – easier to steer, to get in and out. In addition, has a value of length of arms and legs: if you have short hands or feet, better buy a bike smaller or select equipment with minimal stem and the ability to drop the saddle as low as possible.
When buying ask permission to sit on the bike and a bit to go. The size of the frame you may nominally be suitable, but you will feel the discomfort while riding – in that case, give up the purchase, do not expect that, over time, you will be able to get used to the awkward position.
Advice 4: How to change the chain on the bike
The bike needs a decent service and one of its elements, requiring special care - a Bicycle chain. How to change the chain on your bike and why?
Why is it necessary to change the chain?
A Bicycle chain is recommended to be changed every half-two thousand kilometers, because it is subject to great wear, specifically stretched. This is not surprising as this part of the transmission overstretched, a large longitudinal stress, which leads to the removal of circuit elements from each other, which entails a number of unpleasant consequences. It is primarily chain slippage that will occur at applied to the connecting rod load. Thus, to develop greater speed on the bike with a worn chain would be difficult, and even on steep climbs and not have to forget.
The second unpleasant consequence of the wear of the chain will have difficulty switching speeds. When you try to shift the chain from one sprocket to another, it will come off, not being able to rigidly lock to the teeth of the star. Therefore, all the advantages of a bike with lots of speed come to naught.
If for home use cheap bike listed problems aren't so scary, professional athletes and advanced Amateurs lose the greater part of the advantages of their expensive, fancy bikes.
How to determine the degree of wear of the chain?
Convinced of the need for periodic change chains, you should go directly to the explanation of the process. First of all, you should learn to determine when the chain needs replacing, because systematically monitor the mileage is difficult. The most accurate way to determine the degree of wear is to measure the distance from the center Pina of arbitrary (axis, connecting links) to the center of the twenty-fourth after he pins a simple ruler. This distance should be 304,8-306,4 mm. If the distance exceeds the recommended chain requires replacement.
How to change the chain?
There are two types of chains: with lock and pin. The first case is not interesting, because such circuits are used on children's bikes and replacing them is not difficult, for this you will need only a screwdriver.
More interesting is the situation with the second type of chain - chain with pin. First of all, you will need a special tool, squeeze the chain. To remove the chain with the help of available tools is not recommended. Squeeze circuit is used for connector and coupling links of the Bicycle chain. The sequence of actions when working with this tool is as follows:
- positioning pin chain pin opposite to the pomace;
- the screw of the pin, forcing the pin;
- remove the pin.
All, now the chain is disconnected, you can remove and put a new one. The process of installing a new circuit is fundamentally no different from the process of removal.