Replacing a rear hub motor, fitting a complete motor wheel, or swapping a worn freewheel all start with the same job: getting the freewheel off the hub. On a hub motor e-bike, the usual tool often will not even slide on. Here is why, how to confirm what you have, and where forcing it costs you a part, a tool, or both.
First, confirm it really is a freewheel
Freewheel. The sprockets and the ratcheting mechanism are one unit that threads directly onto the hub, and the whole cluster comes off in one piece. The removal tool engages splines in the center of the freewheel body.
Cassette. The sprockets slide onto a splined freehub body that belongs to the hub, held by a lockring. Removing it means unscrewing the lockring while a chain whip holds the sprockets.
The two are not interchangeable: a hub made for a thread-on freewheel cannot take a cassette, and the reverse is also true, so a replacement motor has to match the gear system you plan to run. If you are unsure, take the wheel out and photograph the drive side of the rear hub. That one photo usually shows the interface and the number of sprockets, and it is worth adding to the photos we use to confirm a part fits.
Why a standard freewheel tool will not fit a hub motor
A regular freewheel remover has a small center hole sized for a normal bicycle axle. A hub motor axle is thicker, and the motor cable exits through it. The tool has to pass over both, so a normal remover bottoms out before its splines reach the freewheel.
The answer is a remover with an enlarged through-hole. Large-bore removers are made for 12-spline freewheels and clear 14 mm e-bike axles. Whatever tool you use, check that its spline pattern matches your freewheel and that its bore is wide enough for your axle. Our guide to hub motor dropout width and axle diameter shows how to measure the axle.
The removal, step by step
1. Take the wheel out. Unplug the motor cable at its connector, then loosen the axle nuts. Hub motors use large metric nuts, usually 15 mm and sometimes 18 or 19 mm, which a folding multitool cannot turn; an axle nut wrench set covers all three.
2. Seat the tool all the way. Slide the remover over the axle and cable and push it fully into the splines. Partial engagement is how splines get stripped.
3. Keep it from walking out. On a normal bicycle, Park Tool's method is to snug the quick-release skewer against the remover, turn about one revolution counterclockwise to break it loose, then remove the skewer before unthreading the rest. A hub motor has no skewer, but the same principle works if your axle nut can be threaded back on against the tool. If it cannot reach, hold the tool firmly seated by hand.
4. Turn counterclockwise. A standard freewheel unthreads counterclockwise. Put a large wrench on the tool, or clamp the tool in a bench vise and turn the wheel. An old freewheel can take real force to break loose.
5. Reinstall properly. Coat the threads generously with grease or anti-seize, then thread the freewheel on clockwise by hand until it is fully seated. A dry thread is why the next removal becomes a fight.
What not to force
A tool that stops short. If the remover will not seat fully, forcing it strips the splines. Check the bore size and spline pattern instead.
A pattern that only looks right. Removers are not universal. Park Tool warns that Shimano-style and Falcon freewheels have similar but distinct fittings, and a tool made for one should not be used on the other.
Shallow or rounded notches. Some freewheels have narrow, shallow notches that give a tool almost nothing to grip, and Park Tool notes that attempting removal on that type is likely to ruin both the freewheel and the tool. Decide whether the freewheel is being replaced anyway before you sacrifice a tool too.
Anything that pinches the motor cable. It is the one part of this job you cannot replace with an off-the-shelf bike part. Keep it clear of the tool, the vise jaws and the wrench.
The wrong system. A cassette lockring tool will not remove a freewheel, and a freewheel remover will not remove a cassette. If the tool does not match your drive-side photo, stop.
Two checks before you order a new motor
Many conversion kits ship without a freewheel or cassette unless the listing says otherwise, so you will often be moving the one from your old wheel, whether you choose a complete wheel or a bare motor (see motor wheel versus bare hub motor). And most hub motor kits list a maximum number of rear speeds, typically 9 or fewer, so confirm your cluster is within that limit.
If it still will not move with the correct tool fully seated, a local bike shop is a reasonable next step.