What is A Bicycle Clutch?

Clutch derailleurs are found on most mountain bikes these days. You can also get them for road bikes. But is a clutch worth it?

A bicycle clutch is found on the rear derailleur. The clutch adds tension to the bike chain. The tension keeps the chain in place when you’re traveling over rough terrain, which prevents the chain from bouncing around and decreases the risk of it falling off.

Bicycle clutch added to derailleur after cyclist learned what a bicycle clutch is

Here’s what you need to know before you get a clutch derailleur for your bike….

How Does a Bicycle Clutch Derailleur Help?

Adding more chain tension is the main purpose of the bicycle clutch. Keeping the chain taut increases the security of the chain, especially in poor riding conditions or on uneven terrain.

The Clutch Eliminates Chain Slap on Rough Terrain

With a standard derailleur, the lower arm of the derailleur is responsible for maintaining the tension of the chain. When you hit a bump or a pothole, the jolt causes the arm and the bike chain to bounce.

The bouncing of the chain may cause it to slap the chainstay. The noise is annoying and the slap increases the risk of damage to the chain.

The Clutch Decreases the Risk of the Chain Falling Off

Along with producing unwanted chain noise, a bouncing chain may eventually fall off or shift to the wrong gear when shifting. The clutch derailleur protects against these issues.

Woman riding bicycle over rough terrain after learning what a bicycle clutch is
A clutch makes your chain much more secure during those rough rides.

Disadvantages of Clutch Derailleurs

Clutch derailleurs are designed to protect the chain in rough riding conditions, which requires the clutch to resist movement from the pulley. The friction between the clutch and the pulley may create stiffer shifting and slightly decrease your pedaling efficiency.

A Clutch Derailleur May Make Shifting Stiffer

Engaging the clutch mechanism adds a little stiffness to the shifting process. You may need to use a little more pressure when changing gears.

If you frequently change gears, you may not enjoy the extra shifting effort. It may not feel as responsive, which can be an issue in hilly areas and anywhere with frequent elevation changes.

A Clutch Derailleur May Add Drivetrain Friction

The risk of extra friction is one of the reasons why derailleur clutches don’t appear on most road bikes.

Riders believe that the clutch creates extra drivetrain friction, which may decrease your cycling efficiency. You may need to pedal a little harder when using a clutch.

Nevertheless, controlled tests have found no extra friction from clutch derailleurs. If you notice increased resistance, you may need to clean and grease the derailleur.

Should You Use a Clutch Derailleur on a Road Bike?

A bicycle clutch offers limited benefits for road bikes. You shouldn’t need to worry about chain noise when cycling on good roads. However, a clutch is useful on bad roads.

The extra tension decreases the risk of dropping the chain as you ride over a series of potholes. Some of the top clutch derailleurs for road bikes also feature an on/off switch. You can switch on the clutch mechanism if you plan on riding in an area that has rough terrain.

A clutch derailleur may also add 40 grams or more of weight to your bike. If you want to keep your bike as light as possible, you may want to stick with a regular derailleur.

Clutch Derailleurs Summarized

Clutch derailleurs are commonly found on newer mountain bikes. The clutch mechanism keeps the chain taut when you’re riding over rough ground. In terms of chain control, the chain is less likely to bounce and slap the side of the bike, which decreases the risk of the chain dropping.

While a clutch isn’t as common on a road bike, you may prefer the security of a clutch derailleur when dealing with poor road conditions. It’s also a good consideration for a hybrid bike if you have concerns with chain security.

Image at top: © Glory Cycles | Creative Commons