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!
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.
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.
- 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
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