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How to Convert a Freewheel Hub to a Fixed Hub

Converting a multi-speed bicycle to a fixed gear requires the removal of the freewheel from the rear hub. Old freewheel hubs are symmetrical; the two hub flanges are connected by a uniform center portion. Some hubs have a noticeably larger diameter on the drive side. These are free hubs, and while they can be converted to a fixed gear, they require some specialized parts. Also, be aware that finding parts for old French bicycles can be problematic as they used a different hub threading.

Things You'll Need

Freewheel tool
Large adjustable wrench
Track cog
Chain whip
Bottom bracket lockring
Lockring spanner
Grease
Freewheel spacers

Instructions

- 1
  Examine the freewheel to determine the type of removal tool required. Old Shimano freewheels used a splined tool, while Suntour and many others used a tool with a pair of tabs that engaged the freewheel body. To insert the Shimano tool, the axle assembly must be removed. The tabbed tools fit over the axle and can be held in place with axle nuts in the case of a solid axle or with a quick release lever.
- 2
  Turn the freewheel off the hub by turning it counter-clockwise. You need a large adjustable wrench at least 12 inches long as it requires considerable torque. If it will not succumb to the wrench, put the wheel into a bench vise and clamp the jaws onto the freewheel removal tool. The wheel can be turned counter-clockwise to remove the freewheel. When it breaks free, remember to loosen the axle nut or quick release. Otherwise you risk stripping the hub threads.
- 3
  Clean the hub threads to remove any dirt or grease. Inspect them to see they're in good condition without any signs of cross threading, galling or corrosion. Dissimilar metals can corrode through galvanic action, effectively welding the parts together. If the freewheel was extremely tight, do a careful inspection. If threads are missing or damaged, do not use the hub.
- 4
  Apply a dab of grease to the hub threads and install the new cog by turning it clockwise onto the hub. Do this by hand, not with a tool. If you encounter any resistance in the first full revolution, stop. Back the cog off and try to install it again. Do not risk cross-threading the cog. Once it's in place, put the wheel into the frame and check the alignment of the cog and the front chain ring. Ideally, they should be in the same plane for long chain life and minimal noise. A small misalignment can be corrected with one or two freewheel spacers under the cog.
- 5
  Tighten the cog onto the hub with a chain whip. Use as much force as possible. Thread a bottom bracket retaining ring onto the hub to help keep the cog in place. Tighten it with a bottom bracket spanner.

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