The way to count chain links is by counting each outer link.
Motorcycle and Bicycle chains contain inner and outer links. Outer links are bigger and clamp onto the Inner links (See image)
Some folks call these inner half-links and outer half-links.
1 complete link includes 4 pins.
A properly cut chain will have either a master link as the first one in the sequence (or, an outer link if no master link is used)
Bicycles and motorbikes need chain replacements when the chain develops enough wear on the pins and bushings that the chain appears to have “stretched” it can cause slipping.
Motorcycles need to be replaced 2% stretch.
Bicyles need to be replaced at 1% stretch.
Worn out chains slow down the shifting of gears, and they can grind down the sprockets, causing additional repairs.
See Related: How To Measure Chainsaw Bar Length
Measuring For Chain length
When Measuring for chain wear on a motorcycle, you want both wheels on the ground. Pull the chain away from the rear cog. Less than 1/2 of the cog teeth should show, indicate less than 1″ of throw.
Replacement chains are not sold in the exact length. Most of the time, the bike chains come longer than needed and will need to be cut to size with a chain break tool.
For this article, we will look into different methods that you can use to size the bicycle or motorbike chains.
Keep the bike secure. A maintenance stand makes this process easier. With a maintenance stand you can secure the frame, but turn the wheel and chain to count links.
Mark the first outer link with a grease pen (I’ve also used a sharpie for this). Now, if the chain is already visibily cut, or if you have pulled the chain off of the bike, this step is unneeded. You just want to be able to tell when you have circled back around.
Count each outside link by two’s. This will take into account the inner link as well. Keep in mind that there will always be an even number of links since the inner plates must always attach to outer plates. YOU MUST ALSO COUNT THE MASTER LINK.
If the chain is already detached, you can get a rough estimate by laying the new chain and the old chain next to each other and comparing lengths. Worn-out chains, however, stretch out and may appear to be longer than they actually are.
Counting chain links is a more accurate sizing technique. A standard motorbike chain box has 120 links with 60 inner and outer links, making 120 links and measuring about 60 inches long. Bicycle chains are generally sold in about 114 or 116 links (AKA half-links, for the purists). If working on a tandem or a recumbent with a long chain stay, it is possible to combine multiple chains.
After you’ve counted the correct size, you can detach the extra links with the use of a chain tool.
Protip: only push the roller pin most of the way out — not all of the way. Leaving it sticking out of one outer plate, will make it easier to get the pieces lined up when re-assembling.
Chains either use master links or are connected with the rivets (roller pins). The Master link has two removable outer links that connect the chain ends together and does not require tools to install. Otherwise, you’ll need a chain link tool to press the roller pins into place.
A Note About Bicycle Chain Width
- 11-speed is narrowest at 5.4 mm wide
- 10-speed is 5.88 mm wide
- 9-speed is 6.7 mm wide
- 6, 7 & 8-speed is 7 mm wide
- Single Speed bicycle use 1/8-inch wide chains
If you buy a chain that is too long, it will hang and interfere with the gear shifting. When too short, it can cause too much tension on the derailleur hanger, damaging it.
Sram and Shimano are generally cross-compatible, but Campagnolo is not.
Chain Slack – Bicycles
Shift the chain on the largest front chainring and to the largest cog on the rear sprocket. The chain length should allow for at least two bends in the rear derailleur pulleys and the derailleur should still hang down and not be stretched horizontally.
Then, shift to the smallest chainring and smallest sprocket. The Derailleur should still have enough tension that it does not rub on itself in this position.
Chain Slack – Motorcycles
Motorcycles have the ability to adjust some of the slack out of the chain. When you push up on the bottom of the chain, there should be about 1.2-1.6 (30 mm to 40 mm).
Changing a bicycle chain or motorcycle chain may seem hard the first time, with the right tool for the job, you can accurately size the bike chain. Exceptions are made to a bike that uses a chain guide for chain length determination and needs to be routed through the system. Remember to add the two rivets before cutting. Chains and cassettes from different manufacturers are interchangeable, but SRAM chains are not compatible with Campagnolo.
Finally, remember to regularly clean and oil the chain as it is exposed to dirt and weather. Regular maintenance is needed to minimize wear on the chain. Use soapy water or a chain cleaner to wash off dirt, and oil the chain after drying.
Regularly check if the chain needs replacement. The chains have a lifespan and need to be changed after they are worn out.
Check for wear of the bike chain to prevent the worn-out chain from damaging the sprocket and the chainrings. Replacing the chain after the bike has cover specific miles might not be efficient as the environment may also play a role. A bike chain will wear out faster in salty areas.
To determine when to replace your old chain, you can use a chain gauge to check for wear. Under load, worn-out chains skip over the sprocket teeth instead of meshing with them.