Replacing an AHEAD Steerer Stem


23

1

2

I am in the shorter percentile of the generation, and even though I bought the smallest frame available, I still felt stretched. Therefore I needed to shorten my frame a little and raise the handlebars. The quickest way to do this, especially if you do not plan to switch to a completely different bicycle, is to replace the stem.

Before you place an order, consider the following:

• Stems come in different lengths. Longer stems provide a more extended position, that improves aeoredynamics but puts more strain on your lower back AND scrotum, and results in „slower” steering. Shorter stems result in a comfortable, more elevated rider position, but can make a bike a bit nervous.

I personally went for an adjustable stem of the same length as the original, to give me an option of having the exact same handling when out of town, and more comfort when rolling the streets. Having replaced the stem I can now adjust my position and I really feel the difference.

• Stems come in different diameters, which was a bit unexpected. This applies to handlebars, which can be 22.2, 25.4, 31.7 mm (to name a few options), and to steering tubes (forks) that come in two different sizes that I cannot recall.

So before you proceed, measure your existing stem, as well as the bars and the steering tube.

Supplies:

1 stem

1 bicycle

1 set of hex keys

Teacher Notes

Teachers! Did you use this instructable in your classroom?
Add a Teacher Note to share how you incorporated it into your lesson.

Step 1: Buy a New Stem

Once you have measured the diameters and circumferences, go online and buy a new stem:

1. Look for the options in stores, find out internet is cheaper.

2. Look for the options on e-bay, find out they can’t beat Aliexpress.

3. Order an adjustable bridge. I went for this one:

https://www.aliexpress.com/item/33034649916.html

4. Wait for some three weeks for the goods to arrive, unpack and admire your new stem.

Step 2: Secure the Bicycle

Secure your bike and make sure that the front fork does not fall out:
• If you do not have a service stand, keep both wheels on the ground for the whole time, for example, stand over your bike.

• If you have a service stand, hang your bicycle on the stand and tie the fork to the frame with a string or wire.

Step 3: Remove the Steering Bar

Obtain the right tool and undo the bolts that hold the steering bar. Put the bar aside, it will be easier to remove the old stem without the bar getting in the way.

Step 4: Remove the Top Cap

Undo the bolt that holds the top cap and remove the cap.

Step 5: Remove the Stem

Undo the two bolts that secure the stem to the steering tube, and remove the stem to expose the steerer tube.

Step 6: Fit the New Stem

Test fit your new stem to see if the steering tube ends just below the edge of the stem, some 2 milimeters will do. This will allow for the adjustment of the headset bearings. If needed, add or remove stem washers. Do not tighten the stem bolts yet.

Step 7: Replace the Cap

Replace the cap and tighten the top bolt. Try moving the fork: if you feel any play in the steering bearings, tighten the bolt a bit more; if you feel that the fork starts having trouble spinning, loosen the bolt. Rule of thumb: make it tight but not rock-solid tight.

Step 8: Secure the Stem

Align the stem with the front wheel, and then tighten the two bolts that secure the stem to the steering tube.

Tighten one bolt lightly, move to the other one and tighten with the same force as the first one, then go back to the first one and keep tightening both bolts by a bit, until you tighten them really well.

Step 9: Install the Handlebars

Undo the bolts that hold the handlebar cage and put the bar in place.

Tighten the bolts of the handlebar in an alternating pattern (for example, 1-4-2-3), to avoid putting too much strain on each individual bolt.

Step 10: Optional: Adjust the Angle

If your new stem is adjustable, adjust the angle and tighten the bolt well.

Step 11: Go Out!

Go out and ride!

Be the First to Share

    Recommendations

    • Make it Glow Contest

      Make it Glow Contest
    • STEM Contest

      STEM Contest
    • Furniture Contest

      Furniture Contest

    2 Discussions

    0
    None
    Alex in NZ

    25 days ago

    This is a really good instruction for how to optimise your bike steering leverage! Thank you for sharing all your work, and good luck for long-distances without lumbar problems :-)

    1 reply