A bicycle chain is a collection of links with pins, plates, and rollers that connect the front and rear gears, allowing you to pedal. Chains tend to come loose for a variety of reasons (for example, improper adjustments and damage). However, this problem is easy to fix. Your hands can get a bit dirty with grease, but you'll be pedaling your bike again in no time.
Steps
Method 1 of 3: Reconnect the chain
Step 1. Examine the drive chain first
If you have bent or broken parts, they should be repaired or replaced before reconnecting the loose chain. Make sure to examine not only the chain itself, but also the gears and cassette (which are the gears). This detail is especially important after an accident to ensure that there is no damage.
After you have your bike chain repaired, it's a good idea to check the cassette, gearshift, and limit bolts to see if they are properly adjusted or need replacement
Step 2. Turn the bike upside down or hang it from a stand
In this way, you will make it easier to fix the chain and prevent the bike from rolling while you work. You must turn the bike so that it rests on the seat and the handlebars. Place it gently on the ground to avoid scratches and marks.
The brackets hold the bike upside down in the air and are great for maintenance. However, since most chains come loose while riding, you probably won't have access to a support. Instead, you can place the front of the seat on a large horizontal pole. Keep the bike about 4 feet (1.2 m) off the ground or at least high enough so that the rear wheel is off the ground
Step 3. Observe which gear the bike is in
Shifters are the small machines on the front and rear gears that physically move the chain from one gear to the other. Notice where it currently rests by checking the derailleur, which will be aligned with the gear. The goal is to put the chain back on this gear.
- The front derailleur, right next to the pedals, looks like a small metal bracket hovering over the gear where the chain should be located.
- The rear derailleur, which sits next to the rear wheel, looks like a small mechanical arm. This arm slides back and forth under the cassette (the gear collection) to move the chain and will be located under the correct gear.
- Many bikes indicate the gear number on the handlebar, but you must know how to interpret it for it to make sense:
- Left hand adjusts the forward gears: 1 is the gear closest to the bike, or the smallest gear.
- Right hand adjusts rear gears: 1 is the gear closest to the bike, which is the largest gear.
Step 4. Push the rear derailleur arm toward the handlebar to loosen the chain
This is the small metal arm next to the gear on the bottom of the derailleur. Usually there is a small metal square right next to the gear that allows you to push the derailleur without getting dirty with so much grease. This should be bent gently towards the front of the bike so that the chain hangs quite slack.
Step 5. Use your other hand to slide the chain back over the correct gear
Use 2-3 fingers to lift the chain up and place it over the appropriate rear top. Bring the other end of the chain to the bottom of the front gear and hold it there. You should have enough slack to fit 10-15 sprockets over the sprocket in the chain slots. Slowly release the derailleur once you get a few sprockets in place.
You can also use a pencil, pen, or small stick to guide the chain into the gears if you don't want to use your fingers
Step 6. Pedal the bike backward slowly for 1 full rotation with your hand
As you pedal, you will notice that the sprockets you attached by hand will guide the rest of the chain into place. After the first rotation, you should pedal forward for 2-3 more rotations to make sure the chain stays firmly in place.
Make sure you're pedaling in the right direction. The rear wheel will move as you pedal forward, but not backward
Method 2 of 3: Take Care of the Chain
Step 1. Take care of the transmission to prevent the chain from coming loose
The powertrain is the transmission of the bicycle that consists of all the parts that make the rear wheel move: chain rings (the big gears next to the pedals), a cassette (the collection of gears on the rear wheel), a rear derailleur (the metal arm on the rear wheel) and the chain itself. As dirt, sand and grime accumulate on the transmission, it wears out and becomes prone to bouncing and loosening.
- Frequent transmission cleaning and maintenance can add years to the life of your bike.
- You should put the bike upside down or hook it onto a stand so you can work on the powertrain.
Step 2. Use an old rag and some eco-friendly degreaser to scrub the chain
Eco-friendly degreaser, sometimes referred to as a biodegradable solvent, is a powerful detergent that cuts through grime, but doesn't spoil the chain. Most bike shops offer it along with chain lube. If you don't have one, you can use rubbing alcohol. Pour some onto a damp cloth and gently hold it on the chain with one hand. Use the other hand to pedal the bike, passing the chain through the rag for 2 or 3 cycles.
- You should cycle 2 to 3 by putting pressure on the top and bottom of the chain. Then a few more cycles putting pressure on the sides.
- Lightly wipe off any grease or grime residue with the rag if you still notice it.
Step 3. Use a bicycle cleaning brush or an old toothbrush to clean the gears
Like human teeth, gears need flossing from time to time. Dip the brush in the biodegradable solvent or rubbing alcohol and run it between each gear while pedaling with your other hand. This will remove grease buildups that can dislodge the chain if they are allowed to get too big.
Use a screwdriver to scrape off hard-to-reach areas or fine, small spots. A screwdriver is the ideal tool to remove any grime on the rear derailleur pulleys
Step 4. Remove any visible dirt on the gearbox and chainrings
If it looks dirty then you should get rid of it. Use the damp cloth, a brush, and a bit of degreaser to reach every possible nook and cranny and make the bike look spotless. You should let the bike do the work for you whenever possible, keeping the rag or brush in place while you turn the pedals. Common areas to focus on include the following:
- both sides of the sheave and the controller pulley wheels (which are the little sprockets on the shift arm)
- the rear (closest to the bike) of the chainrings
- the bike frame, gaskets and hinges near the chain
Step 5. Buy a cleaner producer to treat excessively dirty chains
If a rag and toothbrush aren't enough, you're going to need a chain cleaning tool. These little boxes are fastened on the chain. Add degreaser and hold the tool in place as you pedal the bike backwards, allowing you to automatically brush and scrub the chain links. These only cost $ 20-30 and often come with a degreaser and brush.
Step 6. Lubricate the bike chain after cleaning
Purchase a bottle of lubricant to lubricate the chain and protect it from dirt and moisture. After cleaning and drying the chain with the rag, you should slowly turn the pedals. Apply a single drop of lubricant every 2 or 4 links, right at the joint where one link meets another. After treating the entire chain, you should change gears and apply another 10-12 drops.
- Use a clean rag to wipe excess chain lube after you're done, as the extra lube can hold in dirt and create grime.
- The goal is to apply a light coat of lubricant over the entire chain.
- Every time you ride the bike in the rain, clean the chain, or detect a squeak, you should apply lubricant.
- Feel the chain with your fingers. If it is dry to the touch, then you should apply more lubricant.
Method 3 of 3: Troubleshoot common problems
Step 1. Learn how to shift correctly to keep the chain in place during climbs
The wrong gear puts pressure on the transmission, and the chain can only stretch long before it comes loose or breaks. The change moves the chain, and if you push the pedals uphill, this can cause you to lose the sprockets of the next gear. Some tips for making a safe switch include the following:
- Make the change before reaching a climb. Don't wait until you can barely pedal to make the change. As a general rule, your feet should always move at the same speed. You must continue to make changes for this to be possible.
- You should use "gentle pressure" when making the change. Just when making the change, you should relax your feet as if you were releasing the gas. The goal is not to stop pedaling, just to add less weight to the pedals. Work to time this movement with the change. Then resume normal pedaling.
Step 2. Tighten the limit bolts if the chain always comes loose in the same direction
This is a common occurrence if, when shifting to one of the “extreme gears” on the opposite side of either gear set, the chain continues and becomes loose. Limit bolts tell the gearshift to stop moving in one direction, and if the limit is too wide, the chain will continue to move when shifting, even though there are no gears to catch it. Both the front and rear derailleurs have small limit bolts labeled “H” and “L” for the high and low limits.
- Turn the “H” bolts clockwise to prevent the chain from moving too far to the right, away from the bike.
- Turn the “L” bolts clockwise to prevent the chain from moving too far to the left and into the wheel at the rear or to prevent it from falling between the seat tube and the chain ring at the front.
- If you are in the furthest gear, you will notice that the derailleur moves as you tighten the bolts. Make sure it lines up in the middle of the gear.
Step 3. Replace worn chains or those with broken or bent links
Over time, both the chains and the cassettes will wear out due to friction, which means that the gear sprockets cannot be firmly locked into place on the chain. To check the chain, you should use a ruler to measure a distance of 12 inches (30 cm) between 24 pins on the chain. The pins are the small circles in the middle of the links when looking at the chain from the side. If the twelfth pin is more than 1/16 inch (2 mm) outside of the 1 foot (30 cm) mark, you will need a new chain.
- It is better to replace a chain with bent or glued links than to try to replace individual links. Replacing a single link in a chain means that the links will not wear out at the same rate, which could be dangerous. If you absolutely must replace a link, make sure it is the same make as the chain and is designed for a bike with the same number of speeds.
- If the chain is covered in rust or the links are having trouble moving, it is best to buy a new chain.
- Chains generally wear out faster than cassettes and are much cheaper to replace.
Step 4. Determine if you need a new cassette
Cassettes are harder to diagnose than strings, but if you feel like you need a new one, it probably is. If the chain constantly jumps on the gears, slips, or comes loose when pedaling, you probably need a new cassette. Bring the bike to the shop if you have any confusion to conduct a personal assessment.