What is a Bicycle Freewheel

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A bicycle freewheel is a device that allows the rear wheel to spin freely when the pedals are not being turned. The whole system consists of a set of sprockets (cogs) that are mounted on a ratcheting mechanism that engages and disengages with the hub when the rider pedals or coasts.

Just like what the freehub does, the purpose of a freewheel is to enable the rider to coast without having to pedal constantly, which can save energy and reduce fatigue.

But what is the difference? No worries. In this article, we will answer all questions about the freewheel, such as how it works, what its features are, how it compares to a freehub, how to remove and install it, how to service it, etc.

History and Evolution of the Bicycle Freewheel

The first bicycle freewheel was invented by William Van Anden and patented in the United States in 1869. This early freewheel consisted of a single sprocket that could rotate freely on a threaded axle. However, it didn’t gain much popularity initially as most cyclists preferred fixed-gear bikes, where the pedals are directly connected to the wheel.

It wasn’t until the 1880s that bicycle freewheels started to become more widespread. Cyclists began to appreciate the benefits of being able to coast and brake by backpedaling. This led to the development of multi-speed bikes that used derailleurs or internal gear hubs to change gears.

As the 20th century rolled in, bicycle freewheels became more sophisticated. Manufacturers started incorporating multiple sprockets and ratchet mechanisms, improving their performance and durability. Standardization also became more prevalent, with different manufacturers adopting common thread sizes and removal tools.

In 1978, Shimano introduced a game-changing innovation in the cycling world – the freehub. Similar to a freewheel, a freehub also allows for coasting and backpedaling. However, the ratchet mechanism is integrated into the hub instead of the sprockets. Additionally, a freehub uses separate cassettes of sprockets that slide onto the hub instead of being screwed on.

Freehubs offer several advantages over freewheels. First and foremost, they are lighter in weight, making your bike more agile and responsive. They also tend to be more durable and easier to maintain. With a freehub, you can simply replace the cassette instead of the entire freewheel. This not only saves you money but also allows for greater compatibility and a wider gear range.

Today, freehubs have become the standard on most modern bikes, especially road bikes and mountain bikes. They have revolutionized the way we ride and have made shifting gears smoother and more efficient. However, freewheels are still used on some older bikes, single-speed bikes, BMX bikes, and some low-end bikes.

How a Bicycle Freewheel Works

A bicycle freewheel system consists of three main parts: the sprockets, the ratchet ring, and the threaded body. Let’s take a closer look at each of these components:

1. Sprockets: The sprockets are the toothed rings that mesh with the chain and provide different gear ratios for the rider. They are attached to the hub and rotate as you pedal.

2. Ratchet Ring: The ratchet ring is a circular metal plate that has angled teeth on its inner surface. It is located inside the freewheel body and is responsible for engaging and disengaging the pawls.

3. Threaded Body: The threaded body is a cylindrical metal part that screws onto the hub. It has pawls, which are spring-loaded levers, on its inner surface. The pawls engage with the teeth on the ratchet ring to create a positive connection between the hub and the freewheel.

When you pedal forward, the chain turns the sprockets, which in turn rotate the ratchet ring. The pawls on the threaded body engage with the teeth on the ratchet ring, creating a positive connection between the hub and the freewheel. This transfers the pedaling force to the rear wheel, propelling the bike forward.

When you stop pedaling or pedal backward, the chain stops turning the sprockets, which also stop rotating the ratchet ring. The pawls on the threaded body disengage from the teeth on the ratchet ring, creating a free connection between the hub and the freewheel. This allows the rear wheel to spin independently of the pedals, enabling you to coast or backpedal.

Features of a Bicycle Freewheel

A bicycle freewheel has several features that affect its performance, durability, compatibility, and maintenance. Here are four major features, which I personally believe:

1. Number of Sprockets

One of the key features of a freewheel is the number of sprockets it has. Single-speed bikes typically have just one sprocket, providing a fixed gear ratio for all riding conditions. On the other hand, multi-speed bikes have two or more sprockets, offering different gear ratios for different riding conditions.

The number of sprockets on a freewheel can range from two to seven, with five to seven being the most common. Having more sprockets gives you a wider gear range and more options for shifting and adjusting your pedaling cadence. However, it also means more weight, complexity, and cost.

2. Size of Sprockets

The size of each sprocket on a freewheel is measured by the number of teeth it has. Smaller sprockets provide higher gear ratios, which are suitable for faster and flatter riding. On the other hand, larger sprockets provide lower gear ratios, which are better for slower and hillier riding.

The difference in size between adjacent sprockets affects the smoothness and accuracy of shifting. Smaller differences provide smoother and more precise shifting, while larger differences result in faster and more noticeable shifting.

3. Type of Ratchet

The type of ratchet in a freewheel determines how it engages with the hub. There are two main types: star ratchets and pawl ratchets.

Star ratchets have a star-shaped ring with multiple teeth that engage with a spring-loaded sleeve on the hub. They provide fast and quiet engagement but are more expensive and less durable than pawl ratchets.

star ratchet

Pawl ratchets, on the other hand, have a circular ring with fewer teeth that engage with spring-loaded pawls on the hub. They provide slower and louder engagement but are cheaper and more durable than star ratchets.

4. Thread Size

The thread size of a freewheel determines how it attaches to the hub and what type of hub it is compatible with. There are several standard thread sizes, including ISO (1.375 x 24 TPI), British (1.370 x 24 TPI), French (34 x 1 mm), and Italian (35 x 1 mm).

Most modern bikes use the ISO standard, which is compatible with most hubs. However, some older or vintage bikes may use the French or Italian standards, which are incompatible with most hubs. Therefore, it’s important to check the thread size of the freewheel before buying or installing it.

Comparison Between Freewheel and Freehub

Even though the freewheel is an older and simpler system and the freehub is a newer and more advanced system, it does not mean which one is better than the other one overall, because either of them has its pros and also cons.

If you would like to learn more about the freehub system, you can go to this guide of ours on what the freehub is. Here we will mainly list the benefits and drawbacks of both systems.

A freehub has several advantages over a freewheel, such as:

More sprockets: A freehub can accommodate up to 12 sprockets on its cassette, while a freewheel can only accommodate up to seven sprockets on its body. This means that a freehub can offer more gear options and range to the rider than a freewheel.

Better durability: A freehub distributes the load and stress more evenly across the hub bearings, while a freewheel concentrates the load and stress on one side of the hub bearings. This means that a freehub can last longer and require less maintenance than a freewheel.

Easier installation and removal: A freehub can be easily installed and removed with a lockring tool, while a freewheel requires a special freewheel remover tool that fits into its notches. This means that a freehub can be more convenient and versatile than a freewheel.

However, a freewheel also has some advantages over a freehub, such as:

Lower cost: A freewheel is cheaper than a freehub, as it is simpler and requires fewer parts. This means that a freewheel can be more affordable and accessible than a freehub.

Retro appeal: A freewheel has a classic and vintage look that appeals to some riders who prefer old-school bikes or styles. This means that a freewheel can be more attractive and nostalgic than a freehub. Besides, the bicycle freewheel is more suitable for single speed bikes and BMX bikes than a freehub, as it allows more flexibility in choosing the sprocket size and chain tension.

What about its drawbacks?

First, The bicycle freewheel is heavier and less durable than a freehub, as it has more metal and moving parts and bears more stress and wear on the threads and the ratchet mechanism.

Second, it is harder to maintain and repair than a freehub, as it is more prone to dirt, corrosion, and damage and requires more cleaning, lubricating, and replacing.

Besides, it is less compatible with newer bikes and components than a freehub, as it limits the number and size of sprockets and the gear range, while a freehub allows more options for cassettes and derailleurs.

Lastly, the bicycle freewheel is less efficient and smooth than a freehub, as it has more friction and drag in the ratchet mechanism and the chain alignment, while a freehub has less resistance and better alignment.

How to Remove and Install a Freewheel

Tools and Skills You’ll Need

Before you begin, gather the following tools:

1. Freewheel remover tool: This is a specialized tool that matches the notches on the freewheel body.

2. Chain whip: Used to hold the sprockets in place while unscrewing the freewheel.

3. Wrench: You’ll need a wrench that fits the flats on the freewheel remover tool.

4. Vise: A vise is necessary to hold the freewheel remover tool firmly while applying torque.

Removing the Freewheel

1. Secure the wheel: Start by securing the wheel in a bike stand or on the ground with the sprockets facing up.

2. Hold the sprockets: Fit the chain whip around one of the sprockets and hold it in place with one hand. This will prevent the sprockets from spinning while you remove the freewheel.

3. Insert the freewheel remover tool: Fit the freewheel remover tool into the notches on the freewheel body. Insert the tool into the vise with the flats facing up. Tighten the vise around the flats of the tool and make sure it is aligned with the wheel axle.

4. Unscrew the freewheel: Use the wrench to turn the vise counter-clockwise while holding the chain whip in place. This will loosen the freewheel. Once it’s loose, unscrew it by hand from the hub and remove it from the tool.

Installing a New or Cleaned Freewheel

1. Apply grease or anti-seize compound: Before installing a new or cleaned freewheel, apply some grease or anti-seize compound to the threads of the hub and the freewheel body. This will help prevent corrosion and seizing.

2. Align and screw on the freewheel: Align the threads of the freewheel with the threads of the hub and screw it on by hand until it is snug.

3. Secure the wheel: Once again, secure the wheel in a bike stand or on the ground with the sprockets facing up.

4. Hold the sprockets: Fit the chain whip around one of the sprockets and hold it in place with one hand to prevent the sprockets from spinning.

5. Insert the freewheel remover tool: Fit the freewheel remover tool into the notches on the freewheel body. Insert the tool into the vise with the flats facing up. Tighten the vise around the flats of the tool and make sure it is aligned with the wheel axle.

6. Screw on the freewheel: Use the wrench to turn the vise clockwise while holding the chain whip in place. This will tighten the freewheel. Once it’s tight, remove it from the tool and check for any wobble or play.

How to Maintain and Service a Freewheel

Tools and Skills Needed

Before we dive into the maintenance process, let’s make sure you have the necessary tools and skills. Here’s what you’ll need:

1. Degreaser: A degreaser helps clean the dirt and grease from the sprockets and the ratchet mechanism.

2. Grease: Applying grease to the pawls and the teeth of the ratchet mechanism helps keep them lubricated.

3. Spoke wrench: This tool is essential for adjusting the tension of the spokes, keeping the wheel true and balanced.

Now that we have our tools ready, let’s get into the step-by-step process of maintaining and servicing a freewheel.

Step 1: Cleaning the Freewheel

To start, we need to clean the freewheel thoroughly. Follow these steps:

  1. Remove the freewheel from the hub. If you’re unsure how to do this, refer to the manufacturer’s instructions or seek guidance from a professional bike mechanic.
  2. Once the freewheel is removed, spray some degreaser on the sprockets and the ratchet mechanism. Allow it to soak for a few minutes.
  3. Use a brush or a rag to scrub off the dirt and grease from the sprockets and the ratchet mechanism. Be thorough but gentle to avoid damaging any components.
  4. Rinse off the degreaser with water and dry the freewheel with a towel or a hairdryer. Make sure it is completely dry before moving on to the next step.

Step 2: Lubricating the Freewheel

Now that the freewheel is clean, it’s time to lubricate it. Follow these steps:

  1. Apply some grease to the pawls and the teeth of the ratchet mechanism. You can use a syringe or a toothpick to carefully apply the grease.
  2. After applying the grease, spin the freewheel by hand to distribute it evenly. Pay attention to any noise or resistance as you spin the freewheel.
  3. Wipe off any excess grease from the sprockets and the ratchet mechanism with a rag. It’s important not to leave any excess grease, as it can attract dirt and grime.

Step 3: Adjusting the Freewheel

To ensure optimal performance, the freewheel needs to be properly adjusted. Follow these steps:

  1. Install the freewheel back on the hub, ensuring it is securely in place. Refer to the manufacturer’s instructions or seek professional guidance if needed.
  2. Secure the wheel in a bike stand or on a truing stand equipped with a dial indicator or a zip tie. This will help you identify any wobble or hop in the rim or the sprockets.
  3. Spin the wheel and carefully observe for any wobble or hop. If you notice any, it means the wheel is not true and balanced.
  4. Use a spoke wrench to tighten or loosen the spokes on either side of the wheel to correct any wobble or hop. This process may require some trial and error, so take your time and make small adjustments.
  5. Repeat the process of spinning the wheel and checking for wobble or hop until the wheel is true and balanced.

By following these steps, you’ll be able to maintain and service your freewheel effectively. Regular maintenance will not only improve the overall performance of your bike but also extend the lifespan of the freewheel.

Remember, if you’re unsure about any step or encounter any difficulties, it’s always a good idea to consult a professional bike mechanic for guidance.

Over to You

These are all information about the freewheel which we can share with you. Is there something missing? You are welcomed to leave it in the comments section below.

Happy cycling.

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AUTHOR

Randy Joycelyn

Randy is the founder and editor of Cycling Soigneur. He has been passionate about cycling since he was a kid. He has been riding bikes for over 10 years. Cycling has just become a part of life.

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