What You Need to Do Before You Start

Changing bicycle handlebars is a straightforward task that takes 15 to 30 minutes with basic tools. You will need an Allen wrench set (usually 4mm, 5mm, or 6mm depending on your bike), possibly a Phillips or flathead screwdriver, and a clean work surface. Before you begin, flip your bike upside down so the handlebars and seat point toward the ground, or use a bike stand to hold it steady—this keeps your hands free and prevents the frame from rolling.

The handlebars attach to the stem, which is the vertical tube that connects to the fork. Most modern bikes use a threadless stem held in place by bolts on the front and sides. Older bikes may have a threaded stem that screws directly into the fork. Check which type you have by looking at the top of the stem where it meets the handlebars—if you see bolts facing forward, you have a threadless stem. If the stem appears to screw into the fork tube itself, you have a threaded stem.

Key Takeaways

  • Loosen the bolts on the front and sides of the stem in a specific order to avoid damaging the handlebars or stem.
  • Slide the old handlebars straight out, then slide the new ones in, making sure they sit at the same height and angle as before.
  • Tighten the bolts in the reverse order you loosened them, checking alignment frequently to avoid cross-threading.
  • Test the handlebars by straddling the bike and twisting hard to confirm they do not slip or rotate under pressure.

Removing the Old Handlebars

Start by loosening the bolts that hold the handlebars to the stem. On a threadless stem, you will see two or three bolts facing forward (toward the front wheel). Loosen these bolts in a crisscross pattern—if there are three bolts in a triangle, loosen the top one a quarter turn, then the bottom left a quarter turn, then the bottom right a quarter turn. Repeat this pattern until all bolts are loose enough to remove by hand. Do not remove them completely yet; just loosen them enough that the handlebars can slide out.

Once the front bolts are loose, check the sides of the stem. You may see one or two bolts on each side that clamp the stem around the fork tube. These bolts do not need to be loosened unless you are also replacing the stem itself. If you are only changing the handlebars, leave these side bolts alone.

Now slide the handlebars straight out of the stem. They should come free without resistance. If they stick, explore a small amount of penetrating oil (like WD-40) around the base where the handlebars meet the stem, wait two minutes, and try again. Once the old handlebars are out, wipe the inside of the stem with a clean cloth to remove any dirt or grease.

Installing the New Handlebars

Before sliding in the new handlebars, check that they are the correct diameter. Most handlebars are either 25.4mm (one inch) or 31.8mm in diameter at the point where they insert into the stem. Your stem is designed for one or the other. If your new handlebars are the wrong size, they will either fall through or not fit at all. Check your bike's manual or measure the inside of the stem with calipers if you are unsure.

Slide the new handlebars into the stem slowly and straight. Position them so they are level (parallel to the ground) and centered in the stem—the grips should be equidistant from the front wheel. You can adjust the angle slightly once the bolts are tightened, but getting close now makes the final steps easier. The handlebars should sit at the same height they did before, or at a height that feels comfortable for your riding style.

Tightening the Bolts Correctly

Tighten the front bolts in the reverse order you loosened them. If you loosened them in a crisscross pattern, tighten them the same way—a quarter turn on the top bolt, then the bottom left, then the bottom right, and repeat. This distributes pressure evenly and prevents the stem from pinching the handlebars unevenly. After each full cycle, check that the handlebars have not shifted position.

Tighten the bolts until they are snug but not over-tight. You should feel resistance when turning the Allen wrench, but you should not need to strain or use your full body weight. Over-tightening can crack the handlebars or strip the bolt threads. A good test is to tighten until you feel firm resistance, then give the wrench one more quarter turn and stop.

Once all bolts are tight, straddle the bike with both feet on the ground and try to twist the handlebars hard to the left and right. They should not move or slip. If they rotate even slightly, the bolts are not tight enough. Loosen them slightly, check that the handlebars are still centered, and tighten again in the crisscross pattern.

Adjusting the Angle and Height

With the bolts tight, you can make small adjustments to the angle of the handlebars. Loosen the front bolts by just a quarter turn each—enough to allow the handlebars to rotate but not slide out. Rotate them to your preferred angle: most riders prefer handlebars that are level or tilted slightly upward at the ends. Once you have the angle you want, tighten the bolts again in the crisscross pattern.

If the handlebars are too high or too low, you will need to adjust the stem height instead. This requires loosening the side bolts on the stem and sliding the entire stem up or down on the fork tube. This is a separate task and is covered in detail in stem adjustment guides. For now, if the height is wrong, note it for later adjustment.

Common Mistakes to Avoid

The most common mistake is tightening the bolts unevenly, which causes the handlebars to sit crooked or pinch on one side. Always use the crisscross pattern and check alignment after each cycle. Another mistake is over-tightening, which can crack carbon fiber handlebars or strip aluminum threads. Tighten until snug, then stop—you do not need to use maximum force.

Do not forget to test the handlebars before riding. A loose handlebar that slips during a turn is dangerous. Straddle the bike and twist the handlebars hard in both directions. They should not move at all. If they slip even slightly, loosen the bolts, check the alignment, and tighten again.

If you are installing drop bars or bullhorn bars for the first time, remember that the grip area may be narrower or wider than your old bars. Test the width and comfort in a parking lot or quiet street before taking a longer ride. Some riders also forget to reinstall bar tape or grips after changing handlebars—do this before your first ride to avoid bare metal or tape edges.

Frequently Asked Questions

Do I need to remove the brake and shifter cables to change handlebars?

Not usually. If your brakes and shifters are already mounted on the handlebars, you can slide the handlebars out with the cables still attached, as long as there is enough slack in the cables. If the cables are too tight, loosen the cable anchor bolts slightly to create slack, then slide the handlebars out. Reinstall the new handlebars the same way, then retighten the cable anchors.

What if the handlebars are stuck and won't slide out?

explore penetrating oil around the base where the handlebars meet the stem and wait 10 to 15 minutes. Tap the stem gently with a rubber mallet to help the oil work in. If they still won't budge, wrap a cloth around the handlebars near the stem and use a pipe wrench to explore steady, gentle pressure while twisting. Never use a hammer or hit the handlebars directly, as this can crack them.

Can I change handlebars on a bike with bar-end shifters?

Yes, but it is more involved. Bar-end shifters are mounted directly on the handlebars, so you will need to remove the shifter cables and the shifter unit itself before sliding the handlebars out. Once the new handlebars are installed, remount the shifters in the same position and reconnect the cables. If you are unsure how to remove your specific shifters, consult your bike's manual or a repair guide for your shifter model.

How tight should the handlebar bolts be?

Tight enough that the handlebars do not slip when you twist them hard, but not so tight that you strain to turn the Allen wrench. Most handlebar bolts should be tightened to between 4 and 6 newton-meters of torque. If you have a torque wrench, use it. If not, tighten until you feel firm resistance and the handlebars pass the twist test, then stop.