Stuck Freewheel - Freewheel Removal Tool Slipping - Grind Weld Heat Remove - Too Few Thread on Hub

My Pacific Cycles winter bike, the Dolomite or Schwinn Biggity, was not properly geared. I decided to replace the freewheel with one that had 34 teeth as opposed to the original with 28 teeth. Lower gearing means less stress on my knees, chain and it makes it possible to climb hills with minimal effort.

A Sunrace  MFM300-7 model was available, so I swapped it out. After about a month, I had a flat tire and noticed a lot of wobble on the freewheel. I couldn't be sure that it was a problem, but it wasn't terribly reassuring. I decided to to go back to the original.
No luck using my cassette tool, which worked with all other freewheels, so I went out and bought the Park Tool Freewheel Removal Tool 1.3. No luck,  the tool slipped. It felt actually looser that then cassette tool. Tape or paper shims made no difference.

I tried the impact wrench and still no luck.

Why not make my own tool? I took a nut that was originally for my angle grinder to belt sander project, ground it to a taper and hammered it in the freewheel. A little nudge, but the nut's steel was too soft and it slipped.  The ideal setup would have been tool steel cut like a screw extractor.

Next up, at least save the sprockets to use on another freewheel: I was a little lazy, so I used the angle grinder to cut off the lock ring and set cog. The remaining six cogs are still usable.

Trying to cut the outer ring that rotated freely, it seemed pointless as it moves with the grinder and the angle tough to cut. Had I the freewheel servicing tool, to remove the lock ring and remove bearings, palls etc, I would have been less noisy etc. The following steps would not have been necessary...

Somewhat discouraged, welding the core of the freewheel to the outside, where it can be grabbed by pipe wrench, was another effort. The heat of the welding, was intense enough to melt the plastic guard behind the freewheel, seeing it now possible to recover my spokes, but I still wanted to get that freewheel off.

The foot long pipe wrench wasn't quite long enough to make it easy to remove the freewheel to make it budge or even make a sound. Thinking that I should call it day and try to recover my spokes and rim, the blowtorch was in reach. I heated up behind the freewheel at the joint of the hub, gave another shot with the pipe wrench. Voilà! The freewheel came off.

What was the issue? Sunrace tolerances are too low - too much slack, and the freewheel hub was not threaded deeply enough such that the freewheel cut thread into the hub making it so difficult to remove.

Did I put some grease on the hub before installation? Yes. Was it a good idea? Not sure. Maybe it allowed the freewheel to dig in deeper.


Recipe for Removing a Stubborn Freewheel when special tools fail 

Ingredients :

• Angle Grinder
• Welder ( I used a flux core gas-less wire feed. Stick would have been just as good ) 
• Pipe Wrench
• Blow Torch

1. Remove lock ring ( with correct tool / Chain Whip etc.) or cut it with the angle grinder.
2. Remove remaining sprockets to build another freewheel.
3. Weld, 3-4 joints between center of freewheel to outer ring.
4. Heat threaded part of hub and freewheel.
5. Remove freewheel with pipe wrench.