You may have noticed that these rear wheel electric bike conversions kits come with a 6 speed freewheel. The truth is you can use most freewheel free hubs on our kits BUT not Cassette’s.
THEY ARE NOT THE SAME!
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Difference between a Freewheel and Cassette Free Hubs:
The reason for this post is to educate you on the difference and to help you determine which you have on your current bike as there is a great deal of confusion about which is which. It will also help to see how many gears you will potentially lose.
It doesn’t help that the terms “Freewheel” and “Cassette” are often used interchangeably by a lot of people within this industry, an error that causes a lot of wasted time and money.
Freewheels
Traditional rear hubs came with a standardized set of threads to which a standard Freewheel or Sprocket Cluster could be screwed on. This basically allowed any brand of freewheel to be mounted on to any brand of wheel hub. If you wore out your sprockets or just fancied a different gear ratio you could literally unscrew the Freewheel and install a new one.
History and Development of Freewheels
The freewheel mechanism dates back to the early 20th century, revolutionising cycling by allowing riders to coast without pedalling. Initially patented in 1869, its popularity surged in the 1970s due to ease of use and adaptability.
During the late 1980s, advancements in materials and design made freewheels a staple in the bicycle industry. Their widespread use continued until Shimano’s cassette freehub design began replacing the conventional threaded system, offering enhanced performance and simplicity.
Types of Freewheels
Freewheels are offered in both single-speed and multi-speed variations, catering to a wide range of cycling needs. Single-speed freewheels are suited for casual or urban cycling.
Meanwhile, multi-speed freewheels, often 5 to 7-speed, provide greater versatility and adjustment, ideal for varied terrain and more demanding rides. These variations enhance cyclists’ ability to choose appropriate setups for their style and environment.
- Almost all bikes made through the late 1980’s used this system
- Freewheel hubs generally tend to be 5, 6, or 7 speed
- Extractor splines DO NOT turn when sprockets are spun backwards
Maintenance Tips for Freewheels
Regular maintenance of freewheels can prolong their lifespan and ensure smooth operation. Periodically inspect sprockets for wear and clean them from debris with a brush.
Apply a suitable lubricant to achieve efficient spinning. Over-lubrication may attract more grime, so use sparingly. These simple practices minimise wear and enhance performance.
Cassettes
Recently Shimano “Freehubs” have largely replaced the conventional threaded rear hub. This has meant that we have now lost the brand interchangeability that formerly existed but these hubs work so well that they have become the new standard since the late 1980’s.
The Cassette freehub incorporates a ratchet mechanism into the hub body. When you wear out the sprockets you can now replace just the sprockets and not the ratchet mechanism.
These sprockets are commonly sold as a set, called a “Cassette”. These sprockets in a cassette are normally held together by three bolts/rivets more for ease of installation. These bolts/rivets are by no means necessary, they make it easier to keep the sprockets and spacers in the correct position when removed from the ratchet body.
- Cassettes tend to be 7, 8, 9, or 10 speeds (I think you may even be able to get higher)
- Locking splines turn with sprockets when spun backwards
- Most have a distinctive bulge on the right end of the hub barrel
Brands and Compatibility Considerations
When considering upgrades, it is important to note compatibility. Shimano and SRAM dominate the cassette freehub market with extensive options.
Ensure that the chosen cassette is compatible with your drivetrain to avoid issues. Mixing brands may require specific adjustments, or might be entirely incompatible. Proper research into your bicycle’s specifications can save time and effort when upgrading components.
Benefits and Drawbacks of Cassettes
Cassettes offer improved weight distribution and ease of maintenance compared to freewheels. Since the ratcheting mechanism is part of the hub, cyclists need only change sprockets as they wear.
However, cassettes generally require more initial investment and precise compatibility checks. Despite potential drawbacks, their efficiency and reliability make cassettes the preferred choice for modern bicycles.
