Should I replace chainring together with cassette and chain?


Just like any tool that sees substantial use, bikes will also wear out over time. The most obvious and first to jump into mind is the tires. However, one that is often overlooked is the chain and other drivetrain components. Keeping the drivetrain in good shape and running smoothly will ensure a long life for your bike and a smooth commute for you. 

Should I replace the (front) chainring when replacing a cassette and a chain? If the chain and cassette are replaced in time, the chainring’s lifespan increases a lot, if they are excessively worn, then a chainring replacement is warranted. Signs of a worn chairing are light peeking through between the chain and the chainring, bent and broken teeth, and shark fin-shaped teeth.

Read on to find out more about what to look for and when to replace it!

How often should I replace the chainring?

When it comes to the drivetrain on a bicycle, it is important to keep it running smoothly. This ensures a fun and successful commute, mountain bike sesh, gravel grind, or road meander. 

Generally, it comes down to the rule of 3s. When replaced on time, you can often go through three chains before replacing the cassette and three cassettes before replacing the front chainring. 

This means that as long as the chain and cassette are properly replaced on time, you will rarely need to replace the front chainring. Front chainrings, when cared for, can often last many years!

That said, it is always a good idea to maintain and regularly check the drivetrain. Regular tune-ups will ensure that your bike is shifting properly and not causing abnormal wear. 

It is also essential that you clean and lube your chain regularly to prevent excessive wear. If your chain is showing signs of wear, the best course of action is to replace it.

How often should I replace the chain?

Determining when to replace the chain can be the hard part. There is no definite number or mileage as wear can depend on several factors such as terrain, weather, and usage. 

As a bike owner and rider, it is best to buy a chain checker tool and check chain stretch at regular intervals. For example, every time you check your tires, be sure to check your chain about once every two weeks.

Manufacturers will recommend replacing the chain when it reaches 0.75% wear or “stretch.” What does that even mean?

A new chain that has no wear will measure one inch per link. One link is a repeating unit of “two links” – one inner pair of links, one roller, one outer pair of links, and another roller. 

As the chain wears, the parts will wear into each other, in particular the rollers. These minute changes in the metal will cause the chain to “stretch” resulting in links that are over one inch long. This is almost imperceptible in a single link but adds up quickly over several links. 

This is where the chain checker tool excels. It can show you chain wear quickly, making it easy to determine the best time to replace your chain. By making this simple process a part of your normal bike routine, you can ensure your bike is working safely and efficiently every single time you head out for a ride.

Do I need to replace the chain together with the cassette?

This is not always the case. As mentioned above, you can generally run three chains through one cassette. That is if they are changed frequently and before getting 0.75% worn. If the wear is greater than that, then all bets are off, and the cassette needs to be replaced with the chain.

Why? You may ask. This is because as the chain wears, the imperfections wear with the cassette. When they wear together, they tend to mirror one another. Replacing the chain on time can prevent these imperfections from causing ever-increasing damage to the cassette.

If the chain has gone far beyond 0.75% wear, it is almost guaranteed you will experience popping and slipping without a new cassette. Even worse, as the cassette wears, it will cause the front chainring to wear as well. 

Just like the chain and cassette, the cassette and chainring wear together. Lack of care for one will result in excessive wear to the other.

While it is not necessary to change the cassette every single time you change the chain, it is a good idea to ensure your chain is properly lubed, cleaned, and often checked to prevent unnecessary and excessive wear to your drivetrain.

How do I know my chainring is worn out?

Let’s say the worst has happened. You’ve completely neglected your bike chain and cassette and suspect your entire drivetrain needs to be replaced. How can you tell when your front chainring is worn out? 

One simple way is to look at the bike on the drive side. Get low to the ground and good and close to the chain ring. If you can see daylight peeking through between the chain and chainring, then the front chainring is worn out.

Another good method is to remove the chain and inspect the teeth. If you see a lot of “shark fins,” quite literally when the teeth become shaped like shark fins, you can be sure it needs replacement. 

Also, look for broken or bent teeth. If you see one or two of those, it is probably in your best interest to replace it.

Another sure-fire indicator is an overly rusty or bent chainring. If you notice excessive corrosion or wobble, it will be safest to get a replacement on the bike. 

Don’t forget, if you’re replacing your front chainring, then be sure ALWAYS to replace the cassette and chain simultaneously!

Do I need to replace the chain with a new chainring/crankset?

YES! When in doubt, change it out! In comparison to other components in the drivetrain, the chain is the least expensive. It is always better to replace the chain than to not. A new chain causes less wear to the other parts and can often save you money and headaches later on. 

If you are replacing your front chainring, then be sure to replace the cassette and chain. 

If replacing the cassette, be sure to replace just the chain. A fresh drivetrain never hurt anyone, except for maybe their wallet!

Conclusion

Replacing your front chainring is not always necessary. If your drivetrain is properly maintained and the chain is replaced at regular intervals, then your front chainring can last for years! On the flip sure, if your drivetrain is completely worn out and has not been updated for years, then it might be best to replace it all. 

Be sure to use the above tips when determining if and when to replace drivetrain components. Always remember the rule of 3s. You can use three chains per cassette and three cassettes per front chainring. If you do this, it will always ensure your shifting is snappy, smooth, and true. Cause no one wants to ride a bike that pops and slips.

See you on the trails! Happy riding!

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