Choosing a bike chain.
If your bike needs a new chain, you will want to make sure to check a few important points about the number of rear cogs on your bike. With this information you will be well on your way to select the correct chain for your bike repair.
Most chains will need to be shortened. A basic chain tool should work well for most home mechanics. More on length at the end of this guide. It is a great idea to replace your chain often to reduce wear of cogs and chain rings. Some riders keep a spare clean chain and so a dirty chain can be swapped quickly. See some of our 2-pack chain options!
The most critical step in selecting a chain is to choose the correct width.
Single speed chains are often 1/8” or 3/32”wide. Super fancy BMX chains can be extra wide at 3/16”. Single speed chains are listed as Singe speed or BMX chains, and may be found on some internal gear bikes as well.
5, 6, 7 or 8-speed
For multispeed chains, count the number of cogs attached to the rear wheel.
The most common multispeed chain is the 3/32” chain. A 3/32” chain is appropriate for a rear wheel with either 5, 6, 7 or 8 cogs. 3/32” chains may have a pin width of 7.1mm or 7.3mm. Some mechanics like the slightly wider pin width on 5 and 6-speed freewheels. We have found that 7.1mm or 7.3mm pin width is not a hyper critical choice
Don’t get mixed up! A vintage 10-speed bike, probably needs a 5-speed chain as 5-cogs and 2-chainrings make a 10-speed. By today’s standard, a 10-speed chain will be for a bike with 10 rear cogs.
9-speed (6.5mm to 7mm wide)
If a bike has 9-rear cogs, it must use a 9-speed chain. You are going to see a pattern coming.
10-speed (6mm wide)
10-rear cogs, means the bike needs a 10-speed chain.
11-speed (5.5mm wide)
11-rear cogs, and yes, the bike needs an 11-speed chain
12-speed (5.3mm wide)
Yep, if you have a 12-speed cassette on your bike, you probably have this pinned down by now! Buy a 12-speed chain!
Notes on chain length – recumbent riders, you are going to want to check here
The length or pitch between each chain link is 1/2-inch. Meaning a 100-link chain will be 50-inches long. A 1/2-inch pitch is the same for nearly all bike chains across the speed ranges.
It is not common to need an extra long chains for most traditional style bikes.
If a bike needs a chain that is extra long, you will want to measure your old chain to see how many chains you may need to hook together to achieve an extra long chain. This mainly applies to recumbents, tandems, some eBikes with very large chainrings, and other utility style bikes.
Some riders that need extra long chains, will need to purchase multiple chains, and will end up with one remaining section of chain. For example: a recumbent bike that needs 150” of chain. If a chain is sold as a 116-link chain, it will be 58” long. In this example, three chains will need to be connected together for a total length of 174”. And 24” (48-links) will need to be removed to match the correct 150” chain length.
We at TheBikesmiths.com hope some of this basic info will help guide you to the correct type of chain you need to keep your bike on the move!