How to Install a Stem on a Bicycle

Correct maintenance of equipment is vital for safety in sports such as cycling. The stem is a highly stressed component that attaches the handlebars to the steerer tube of a bicycle and the headset, which requires regular maintenance. The installation of a stem depends on the type -- quill or threadless. Those two types depend on the type of headset, steering tube and forks on your bicycle. Correct fitting maintenance of these components will ensure you maintain control of your bicycle and prevent parts failure.

Things You'll Need

  • Stem
  • Bicycle frame
  • Bicycle forks
  • Headset spacers (on threadless stems)
  • Spanners
  • Hex keys (also known as 'Allen keys')
  • Grease
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Instructions

  1. Quill Stems

    • 1

      Ensure that your forks, frame and headset are compatible with your stem. Quill stems are single-piece items that attach to threads inside the fork, the top of which does not protrude above the headset.

    • 2

      Apply grease to the inside of the steer tube and to the inside of the wedge or cone-nut, which will grip the inside of the fork's headset tube.

    • 3

      Ensure the wedge or cone-nut are fully loose, and insert into the steer tube, taking care to insert the stem deeper than the minimum insertion line, which should be clearly marked on the stem.

    • 4

      Tighten the bolt that normally appears at the angle of the stem. It's normally a 6 mm bolt, tightened by a hex key.

    • 5

      Fit the handlebars to the stem.

    Threadless Stems

    • 6

      Ensure that your forks, frame and headset are compatible with your stem. Threadless stems clamp directly onto the fork, the top of which protrudes above the headset, using spacers to ensure correct fit.

    • 7

      Select the correct amount of headset spacers. The steer tube on the fork should protrude above the top of the frame steer tube. Sufficient spacers should be added so the top of the stem sits approximately 5 mm over the top of the fork steer tube.

    • 8

      Place the headset spacers over the steer tube.

    • 9

      Insert the fork steer tube into the stem and insert the top-cap into over the hole, tightening the bolt (usually a 5 mm bolt) with a hex key.

    • 10

      Tighten the stem retaining bolts. These are usually a pair of 5 mm hex bolts.