How to adjust handlebar height

Why and how you should experiment with bar height

One of the key things we do to make our test bikes handle better is adjusting handlebar height. Often, the off-the-shelf bar height doesn't lend itself to optimal handling.

Riders will often experiment with saddle height, tyre pressures. bar angle and suspension settings, but few are aware of the benefits of bar height. Bar height is also known as saddle-drop, measured by how far the top of the saddle sits above (or below) the bars. Elite riders normally have drop, where their bars sit below the saddle, whereas recreational riders usually don’t.

Generally speaking, a lower handlebar height reduces your centre of gravity. By placing more weight over the front wheel, you increase traction. Additionally a lower bar height provides a more centred position between both wheels to improve bike control, especially during climbing. These traits are even more noticeable off-road, especially with larger wheeled bikes (29ers).

There is a limit: going too low can make the bike difficult to control. Luckily, experimenting with bar height is easy and most often free. The guide below applies to modern threadless style stems and headsets, if your stem has bolts pinching it onto the steerer tube, it’s most likely threadless.

All the steps below are also documented in this picture gallery.

  • Time: 15 minutes
  • Skill rating: Easy
  • Cost: Free

Tools you’ll need

  • A multi-tool or a set of Allen keys
  • A torque wrench or pre-set Torqkey is recommended, especially if working with carbon or lighter parts
  • Some stems, such as those from Zipp and Ritchey, will need a T20 or T25 Torx key

Use those spacers

The first and easiest way to adjust handlebar height is by moving headset spacers.

This bike features two headset spacers. The cone shaped piece is the headset bearing cover, you can buy shallower versions of these if a very low bar height is desired.

The headset spacers sit on the fork's steerer tube and help preload the headset bearings during adjustment. Generally, most bikes have 20 to 30mm of headset spacers that can be moved freely above or below the stem. All bolts in the stem are standard threaded (‘lefty-loosey, and righty-tighty’).

1. Start with the bike’s wheels firmly on the ground and then loosen the clamp bolts on the back of the stem.

2. Remove the top cap that sits on top of the stem. This will normally take a 5mm Allen key.

3. Slide the stem off the steerer tube.

4. Decide how much you’d like to lower or raise your bar and add or remove the appropriately sized spacer(s).

5. Slide the stem back onto the steerer tube and replace the spacers you just removed into position above the stem.

Ensure there is a 3 to 5mm gap between the steerer tube and the top of your stem/spacer. This will ensure there's enough space for the headset topcap to clamp down and preload the headset bearing. If this gap is not present, check that you have not misplaced any spacers.

6. Now replace that topcap and bolt and tighten till you feel some resistance. This topcap bolt is used to preload the headset bearings. Too tight and your handlebars won’t turn freely, too loose and you will feel a rattle and vibration through the bike.

7. Next, align the stem with the front wheel, so the bar is at a right angle with the wheel. This may take some patience – it helps to straddle yourself over the top tube of the bike.

8. Once the wheel and stem are aligned, evenly torque the stem clamp bolts to the manufacturers recommended torque. This is often around 5 to 8nm.

9. Check your headset adjustment. An easy trick to get this right is to hold the front brake and put one hand on the headset, then rock the bars gently back and forth. Feel for rocking. If you feel any, loosen the stem clamp bolts and tighten the top cap bolt another quarter-turn, then re-torque stem clamp bolts. Repeat until all signs of bearing movement have disappeared and the handlebars still turn smoothly. If you've tightened the bolts too much, you'll feel a tight spot when turning the handlebars.

10. Go and test that new bar height.

Flip the stem

If spacers aren't enough to achieve the affect you wanted, you can flip the stem to make a further change to the bar height. Most mountain bikes will be set up with the stem in a positive position, creating an upward angle, but you can use it the other way round. This uses all the steps above with the addition of unbolting the handlebar from the front of stem.

11. With the bike’s wheels firmly on the ground, make a mental note of the handlebar angle and the brake lever angle. Undo the bolts that hold the handlebar to the front of the stem.

12. Let the handlebar gently droop to the side and now follow the procedure for swapping spacers, outlined in steps 1 to 4 above.

13. While the stem is off the bike, flip it over and then slide it back onto the steerer tube. You'll see the stem has reversed its slope.

14. Reinstall the handlebar, replicating the previous brake lever and handlebar angle. Tighten face-plate to manufacturers recommended torque (generally between 4 and 8nm). Ensure that all bolts are done up evenly, a little at a time, and that there is an even gap top to bottom with the face plate once they're tight. If the gap isn’t even, the handlebar is being pinched.

Proceed with steps 3 to 7 above to preload the headset and tighten the stem.  

You’re now good to hit the trail and/or road to test out the bikes new handling characteristic. It may take some trial and error along with patience to find that perfect height, but once you've got it, you'll be far closer to realising the bike's true potential.

We also previously offered some great advice on mountain bike handlebar position.

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