E-Bike’s Gearing: Upgrading Cassette To Freewheel

Swapping from a cassette to a freewheel is a significant change, but it’s essential to be prepared for the potential challenges involved. This guide will walk you through the process, ensuring a smooth conversion for your e-bike’s gearing.

Identifying Your Bike’s Gear System: Cassette or Freewheel

Before starting any work, identify your e-bike’s gear system – cassette or freewheel – as this will determine the correct tools and parts needed.

1. Visual Inspection

• Look for a lockring on the outside of the gear cluster. If you see one, it’s likely a cassette.
• If you see a recessed area with splines (internal teeth) where a tool would fit, it’s likely a freewheel.

2. Spin Test (if unsure)

• Carefully remove the rear wheel.
• Try to spin the gears backward (counter-clockwise).
• If the entire gear cluster spins freely, including the part where the tool would attach, it’s a freewheel.
• If only the gears spin, and the tool attachment point stays still, it’s a cassette.

Spotting the Differences

• Freewheels screw directly onto the hub and have the ratcheting mechanism built-in. They are more common on older bikes and typically have 5-7 gears.
• Cassettes slide onto a splined freehub body on the hub, and the ratcheting mechanism is within the freehub. They offer a wider gear range (7-12+ gears) and are found on most modern bikes.

Note: Some older bikes might have a 7-speed freewheel, so the spin test is the most reliable way to confirm. If you’re still unsure, consult a bike shop or do further research on your specific bike model.

Freewheel Conversion: Navigating Compatibility

The primary challenge in converting between cassette and freewheel systems lies in hub compatibility. Cassettes require a freehub body with splines for attachment, while freewheels thread directly onto the hub. If your existing hub isn’t designed for your desired system, a new wheel or a costly hub rebuild may be necessary.

Additionally, be mindful of frame clearance, as cassette hubs are wider than freewheel hubs. Switching to a cassette might necessitate verifying adequate space within your frame to prevent rubbing and potential damage. Gear range and drivetrain compatibility are also crucial; freewheels typically offer fewer gears, requiring compatible shifters and derailleurs.

Remember that converting between systems can be both expensive and technically challenging, so carefully weigh the benefits against the potential costs and complexities before proceeding.

Shifting Gears: Swapping Your Cassette For A Freewheel

Beyond compatibility concerns, transitioning from a cassette to a freewheel system necessitates a clear understanding of the removal and installation process.

Removing Your Cassette Gear System

Now that you’ve confirmed your e-bike has a cassette, let’s begin the process. The first step is to carefully remove the existing cassette from your rear wheel.

1. Gather Your Tools

• Cassette Lockring Tool: This specialized tool is designed to loosen and remove the lockring that secures the cassette to the freehub body. Make sure you have the correct type for your specific cassette brand.
• Chain Whip: This tool holds the cassette steady while you loosen the lockring, preventing it from spinning and making the removal process easier.
• Wrench or Adjustable Wrench: You’ll need this to provide the leverage to turn the cassette lockring tool effectively.

2. Remove the Rear Wheel

1. Securely position your e-bike on a bike stand or carefully turn it upside down.
2. Shift the chain to the smallest cog on the cassette.
3. If your e-bike has rim brakes, release the brake cable tension.
4. Loosen and remove the rear wheel axle nuts using a wrench or quick-release lever.
5. Gently slide the rear wheel out of the dropouts.

3. Remove the Cassette

1. Engage the chain whip on one of the larger cogs of the cassette to prevent it from rotating.
2. Insert the cassette lockring tool into the lockring at the center of the cassette.
3. Use the wrench or adjustable wrench to turn the cassette lockring tool counterclockwise to loosen and remove the lockring.
4. Once the lockring is removed, carefully slide the cassette off the freehub body. Depending on the cassette, it may come off as several separate pieces. Note the order of the cogs and spacers for reassembly if needed.

4. Prepare for Freewheel Installation

• If your e-bike’s rear hub doesn’t have threads for a freewheel, you might need to replace the entire hub or wheel with one that’s compatible with a freewheel. Consult your e-bike manufacturer or a qualified technician for assistance.
• Clean the hub’s threads to ensure proper freewheel installation. Use a rag or paper towel with rubbing alcohol, to remove any dirt or grime. This area is usually hard to clean when the cassette is on, so take the opportunity to clean it thoroughly.

Installing Your Freewheel

Once the cassette has been removed, you’re ready to install the freewheel onto your e-bike’s rear hub.

1. Prep the Hub & Freewheel

• Generously apply grease or anti-seize compound to the hub’s threads to prevent seizing and simplify later removal.
• Confirm freewheel compatibility with your e-bike’s hub and desired number of speeds. Double-check the hub’s thread pitch (commonly 1.37″ x 24 TPI, but variations exist).

2. Thread the Freewheel onto the Hub

• Align the freewheel with the hub’s threads and begin rotating it clockwise by hand. It should thread smoothly. If you encounter resistance, stop and recheck alignment to avoid cross-threading.
• Ensure the hub is centered within the freewheel. An off-center axle likely indicates cross-threading, requiring you to start over.

3. Fully Tighten the Freewheel

• Continue threading the freewheel by hand until it’s snug.
• Chain Whip (Optional): Use a chain whip to turn the freewheel further clockwise until fully seated.
• Pedal Power (Alternative): Lacking a chain whip, reinstall the wheel (loosely), engage the brake, and pedal to tighten the freewheel.
• Avoid overtightening, as this can damage the freewheel or hub. It will self-tighten slightly with use.

4. Reinstall & Test

• Carefully align the rear wheel with the dropouts and slide it back into place
• Tighten the axle nuts or quick-release lever securely
• If applicable, reattach the brake cable and adjust its tension.
• Shift through all gears to ensure smooth operation. Verify proper chain alignment and check for excessive wear, as a worn chain can harm the new freewheel.

Freewheel Conversion Troubleshooting

Remember

• Chain Compatibility: Ensure your chain is compatible with the number of speeds on your new freewheel
• Derailleur Adjustment: You might need to readjust your rear derailleur to accommodate the new freewheel