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How to Convert From a Quill Stem to a Threadless

The bicycle stem is the part connecting the handlebar to the fork. Older bikes use a quill stem, which extends into the fork. Most new bikes have threadless stems. A threadless stem can be fitted to a conventional, threaded fork with an adapter and a few common hand tools. The hard part of the job may involve removing the old stem and getting the handlebar out of it. Threadless stems are easily changed, so as a cyclist progresses through the season, longer, lower stems can provide a more aerodynamic position.

Things You'll Need

Threadless stem adapter
Threadless stem
Metric Allen wrench
Permanent marker
Grease or anti-seize compound
Rubber mallet
Penetrating fluid

Instructions

- 1
  Loosen the binder bolt and remove the handlebar from the old stem. Use a permanent marker to provide a reference point on the brake lever and handlebar to assist with reassembly. With dropped handlebars, this requires removing the tape, one or both brake cables and one brake lever. On flat handlebars, remove one grip, one or both brake cables and one brake lever. Integrated shifter cables do not have to be removed from the lever, but the cable housing must be free of the handlebar.
- 2
  Loosen the binder bolt in the stem by turning it counter-clockwise. A quill stem has an expander or wedge inserted into the steering tube of the fork. Turn the bolt three or four revolutions so it is slightly raised above the stem, then hit it with a mallet to pop the wedge loose. The stem may loosen at the same time. If it doesn't, grasp it firmly and twist while pulling up on it. If it will not move, apply penetrating fluid to the stem so it can seep down into the fork. Wait a few minutes, then tap the stem from above with the mallet and try to remove it.
- 3
  Measure the stem diameter. They come in two sizes: 1 inch or 1 1/8 inches. Obtain a stem adapter in the same size. Apply a thin film of grease on the adapter and install the new threadless stem onto it. Some adapters are larger in diameter at the very top, preventing a stem from sliding on from above, but always install the stem before inserting the adapter in the fork. The stem provides more leverage when tightening the expander bolt. Tighten the binder bolts that fasten the stem to the adapter. Insert the assembly into the fork and tighten the expander bolt on the top.
- 4
  Reinstall the handlebar, brake lever, brake cables and handlebar tape or grips. Tape the shift cable housing to the handlebar before applying the handlebar tape. Stand behind the bicycle. Sight along the nose of the saddle, the top tube and the top of the front wheel to align the stem, then tighten it firmly. Some threadless stems will move slightly to the side as they're tightened. If this happens, simply loosen it and turn it to the other side by the same amount. When you tighten it again, the bolts will pull it into proper alignment.

Bicycles