Replacing a bicycle chain is a common maintenance task that can be done at home with a few simple tools. One important step in the process is sizing the new chain correctly. If the chain is too long, it can derail or skip gears. If it is too short, it will not be able to reach all of the gears. The correct chain size will vary depending on the number of gears on the bike and the size of the chainring and cassette. There are a few different ways to size a bicycle chain, but the most accurate method is to use a chain checker tool.
A chain checker tool is a small, inexpensive tool that measures the length of a chain. To use a chain checker tool, simply place the tool on the chain and pull it until it reaches the end. The tool will indicate whether the chain is too long, too short, or the correct size. If the chain is too long, you will need to remove some of the links. If the chain is too short, you will need to add some links. You can purchase chain links at most bike shops.
Once you have the correct chain size, you can install the new chain on your bike. To do this, you will need to remove the old chain and then connect the new chain to the chainring and cassette. There are a few different ways to connect a bicycle chain, but the most common method is to use a master link. A master link is a special type of link that can be opened and closed without the use of tools. To install a master link, simply open the link and connect it to the end of the chain. Then, close the link and you are finished.
Adding Extra Length for Suspension
In case you own a full-suspension bike, there will be a suspension mechanism that works to provide additional travel (the extension of the shock). If this travel is not taken into consideration when sizing the chain, it could cause it to be too short when the suspension is at maximum compression. This problem primarily affects bikes designed for rough terrain, such as downhill or mountain bikes, which usually have greater suspension travel.
To ensure an accurate chain length, follow these steps:
- Measure the chain length using the methods described above.
- Once you have wrapped the chain around the chainring and cassette, connect the two ends but leave a gap of about 6mm between them.
- Apply maximum compression to the suspension by sitting on the bike and compressing the suspension fully.
- Move the rear wheel back and forth to check if the chain is taut. If there is significant slack or resistance, adjust the chain length accordingly.
- Once the chain is properly tensioned under maximum suspension compression, reconnect the two ends permanently.
Table: Recommended Extra Chain Length for Suspension Travel
As a general guideline, here are some suggested extra chain lengths for different suspension travel ranges:
| Suspension Travel | Recommended Extra Chain Length |
|---|---|
| 50mm – 100mm | 2 – 3 links |
| 100mm – 150mm | 4 – 5 links |
| 150mm+ | 6 – 7 links |
Keep in mind that these are approximate values, and the optimal extra length may vary depending on the specific bike and suspension system. It’s always advisable to refer to the manufacturer’s recommendations or consult with a qualified bike mechanic for more precise guidance.
How To Size A Bicycle Chain
To determine the proper size for a bicycle chain, you’ll need the number of teeth on the front and rear sprockets. Once you have these numbers, you can use the following formula to calculate the correct chain length:
Chain length = (2 x number of chainrings) + (number of rear sprockets + 2)
For example, if your bike has two chainrings and eight rear sprockets, the formula would be:
Chain length = (2 x 2) + (8 + 2) = 14 links
People Also Ask
How can I measure my chain if I don’t know the number of teeth on the sprockets?
If you don’t know the number of teeth on the sprockets, you can use a measuring tape to determine the chain length. To do this, wrap the tape around the chain, starting at the rear derailleur and ending at the front derailleur. Make sure the tape is tight, and add 2 inches to the measurement to account for overlap.
What happens if my chain is too long or too short?
If your chain is too long, it can skip gears or fall off the sprockets. If it’s too short, it can put excessive stress on the chain and sprockets, causing premature wear.
How often should I replace my chain?
The lifespan of a bicycle chain depends on a number of factors, including the type of riding you do, the conditions you ride in, and how well you maintain your chain. However, most experts recommend replacing your chain every 2,000 to 3,000 miles.
