E-Bike Gear Upgrade: Switching From Cassette To Freewheel

Budget Hub Motor Compatibility: Many cheap e-bike conversion kits only come with freewheel hubs. If you already bought a $200 freewheel motor and don’t want to eat the cost, converting your existing 7-speed cassette setup to freewheel saves buying a new motor.

Seized Freehub Body: Cassettes can seize onto freehub bodies through corrosion. If your freehub is destroyed and a replacement costs $100-150, buying a complete freewheel wheel for $80-120 can be cheaper. The math matters here.

Simplification Project: Converting a bike for a kid or casual rider who doesn’t need 9 speeds. Freewheels are simpler to maintain and replacement parts cost less. But be honest if this is really about simplicity or just being cheap.

Parts Availability: In some countries, replacement cassettes are expensive or hard to find, while freewheels ship cheap from China. If you’re maintaining bikes in remote areas with limited supply chains, freewheels can make logistics sense.

You Want an 11T Cog: Stop. Freewheels max out at 14T (13T exists but fails constantly). The DNP 11T freewheel has terrible reviews and strips threads off hubs under power. If you need 11T gearing, stick with cassettes or change your chainring.

You Heard Freewheels Are “More Reliable”: This is marketing from budget motor suppliers. Freewheels fail just as often, and when they do, you throw away the entire unit. Cassette freehubs can often be serviced or the cassette replaced individually.

You Think It’s Simple Like Replacing Cogs: You can’t just thread a freewheel onto your cassette hub. The hub needs threads, which cassette hubs don’t have. This requires either a completely new wheel or rebuilding your wheel with a threaded hub.

If You Already Have a Freewheel: You don’t need this guide. You’re just replacing one freewheel with another. Unscrew the old one, grease the hub threads, and screw on the new one. Done.

If You Have 8+ Speeds: Converting to freewheel means losing speeds. Your 8-speed shifters won’t work with 7-speed freewheels. You’ll need new shifters, potentially a new derailleur, and you’re accepting a worse gear range. Calculate these costs before proceeding.

You Cannot Convert the Hub

• Cassette hubs have splines. Freewheel hubs have threads. No adapter converts between them.
• The hub body is machined differently at the factory. You can’t add threads to a splined freehub.
• Anyone selling a “conversion adapter” is lying or selling something for single-speed conversions only.

Your Three Actual Options

1. Buy a complete new wheel with a threaded freewheel hub ($80-150 for basic wheel)
2. Buy a new hub motor with freewheel threading if this is for an e-bike ($200-400)
3. Rebuild your existing wheel by replacing just the hub and relacing spokes ($100-200 labor + $40-80 hub)

Approach	What You’re Buying	Typical Cost	Realistic?
Keep cassette	Replace worn cassette	$40-120	Best option if cassette works
Buy freewheel wheel	Complete wheel + freewheel	$100-180	Makes sense if freehub seized
Hub rebuild	New hub + labor to relace	$150-280	Only if rim is valuable
E-bike motor swap	New freewheel hub motor	$250-450	Check used cassette motors first

The Math: If your only problem is a worn cassette, spending $100-400 to convert to freewheel makes zero sense. Just buy a new cassette for $40-120. Conversion only makes financial sense when your freehub is destroyed, replacement freehubs are unavailable or expensive, and a complete freewheel wheel costs less than fixing what you have.

• Cassette lockring tool (matches your cassette brand – Shimano, SRAM, or Campagnolo)
• Chain whip (holds cassette while you loosen lockring)
• Adjustable wrench or 1-inch wrench for lockring tool
• Bike stand or way to secure wheel

• For e-bikes, disconnect motor cable first
• Shift to smallest cog to reduce chain tension
• Loosen axle nuts or quick-release skewer
• Slide wheel out of dropouts

Wrap the chain whip around one of the larger cogs (more teeth = more chain engagement = better grip). The chain whip prevents the cassette from spinning while you loosen the lockring.

• Insert lockring tool into the center splines
• Turn counterclockwise with wrench while holding chain whip steady
• Initial break requires significant force – this is normal
• Once loose, spin lockring off by hand

The cassette should slide straight off the freehub splines. Some cassettes come off as one unit, others as separate cogs with spacers. Take a photo if they separate so you remember the order (though you won’t be reinstalling them).

Verify Thread Pitch:

Most freewheels use 1.37″ x 24 TPI (threads per inch) but French and Italian standards exist. Verify your hub’s thread pitch matches your freewheel. Starting to thread mismatched parts will cross-thread and destroy both hub and freewheel.

Check Speed Compatibility:

Your freewheel speed count must match your shifters. 7-speed shifters work with 7-speed freewheels only. If you’re converting from 8+ speed cassette to freewheel, budget for new shifters ($30-60) and possibly a new derailleur.

Apply a generous layer of grease or anti-seize compound to the hub’s threads. This prevents seizing and makes future removal possible. Every pedal stroke tightens the freewheel onto the hub, so without grease, you’ll never get it off again.

• Hold freewheel aligned with hub threads
• Turn clockwise (righty-tighty) by hand
• It should thread smoothly with no resistance
• If you feel resistance, STOP – you’re cross-threading

The freewheel should spin freely for several rotations before starting to tighten. If it binds immediately, back it off and try again with better alignment.

Thread the freewheel as tight as you can by hand. Then:

• Option 1: Use a chain whip on the largest cog to give it 1-2 more full turns
• Option 2: Install the wheel loosely, engage brake, and pedal forward to tighten

Look at the freewheel from the side. The hub axle should be perfectly centered within the freewheel body. If the axle appears off-center or angled, the freewheel is cross-threaded. Remove it immediately, clean the threads, and start over.

Frame Spacing Check: Freewheel hubs are sometimes narrower than cassette hubs. If your new wheel measures 126mm or 130mm and your frame is 135mm, the wheel will fit but sit slightly loose. This usually isn’t a problem for casual riding but can cause alignment issues under hard pedaling or on rough terrain.

Why This Matters:

Your freewheel likely has a different gear range than your old cassette. A 7-speed freewheel typically runs 14-34T or 14-28T, while cassettes can go 11-42T or wider. This changes how much chain length you need.

Chain Wear Check: If your chain has significant wear (stretched), replace it now. Worn chains skip on new freewheel cogs and accelerate wear.

High Limit (Smallest Cog)

• Shift to smallest freewheel cog
• Adjust H screw until derailleur pulley aligns perfectly under the smallest cog
• Too far inboard = chain drops off into spokes
• Too far outboard = poor shifting from small cog

Low Limit (Largest Cog)

• Shift to largest freewheel cog
• Adjust L screw until derailleur pulley aligns under the largest cog
• Too far inboard = chain drops into wheel
• Too far outboard = won’t shift to largest cog

Index Adjustment:

After limits are set, fine-tune cable tension using the barrel adjuster on the shifter or derailleur. Shift through all gears. If shifting is slow going up (to larger cogs), add tension by turning adjuster counterclockwise. If slow going down, reduce tension clockwise.

The Physics Problem: E-bike motors generate 40-80 Nm of torque, far exceeding human pedaling force. This torque constantly tries to unscrew the freewheel. The freewheel’s self-tightening action usually overcomes this, but aluminum hubs can strip threads under repeated high torque.

Prevention

• Use quality Shimano freewheels, not cheap generics
• Apply anti-seize but don’t over-grease (too much = slippage)
• Check freewheel tightness every 100 miles for first 500 miles
• Avoid high motor assist in lowest gear (maximum stress on threads)

What to Check

• Verify sensor magnet is positioned within 2mm of sensor
• Freewheel body may be thicker than cassette, requiring sensor repositioning
• Test error codes after installation (Error 21 on Bafang = sensor issue)
• Some motors require recalibration when changing from cassette to freewheel

Lifespan Reality: Budget freewheels (DNP, generic brands) fail faster under e-bike torque. Expect 1000-2000 miles before pawl wear causes skipping. Shimano freewheels last 3000-5000 miles with proper care. Cassette systems typically outlast freewheels by 50-100% under same conditions.

Maintenance: Freewheels are sealed units, so maintenance means replacement. Keep a spare freewheel if you depend on the bike for transportation. They’re cheap enough ($25-40) that having a backup makes sense.