Ahead stem replacement

If you’re planning to replace an ahead stem then before you buy one you may want to know what the options are. Threadless stems come in variety of sizes and lengths and it is important to get the right one. This article will guide you through the process of choosing and fitting the right replacement. 

What is an ahead stem and how does it work?

An AheadSet™ stem is  used on bikes with a threadless steerer tube. It is usually one piece unless the angle is adjustable. An AheadSet™ stem has a cutaway that allows the stem to be clamped directly to the steerer tube when the bolts on the stem are being tightened.

To change your upper body position. you can replace your current stem with a different length or angle. 

different ahead stem lengths and angles

Ahead stem length

If you are looking to replace your AheadSet™ stem with a longer or shorter one then first measure the length of your current one. The measurement is taken from the middle of the bolt

ahead stem length measured from the middle of the bolt

to the middle of the bars and is expressed in millimetres.

ahead stem length measure to the stem clamp

If it is shorter than 150 millimetres, then you will be able to source a longer reach replacement.

ahead stem shorter than 150mm

If it is longer than 30 millimetres, then you will be able to source a shorter replacement.

ahead stem longer than 30mm

Ahead stem angle

Many handlebar stems will have a degree of angle, depending on the style of bike, and this can be adjusted. by flipping the stem.

You can do this if your stem is pointing down and you want your riding position to be more upright

ahead stem pointing down

or it’s pointed upwards and you’re looking for a more aerodynamic position.

ahead stem pointing up

Adjustable stem.

An alternative option offering a variety of angles to find the most comfortable position. 

adjustable ahead stem

Handlebar clamp diameter

Check the central diameter of your handlebars.

measuring handlebar diameter

There are two common sizes 25.4mm and 31.8mm. Make sure that the new one is the correct size.

Replacing a threadless stem

Before you start be aware that when replacing a stem with a different length or angle you may need to replace the brake and gear cables as the current ones might be too short. 

  • While having the bike on the floor, stand in front of it with the wheel in between your legs.
  • Undo and remove the bolts on the front and remove the plate.
  • Remove handlebars.
  • Using a cable tie or strap attach the bars to the top tube of the frame.
  • Now loosen the bolts on the side.
undoing ahead stem bolts
  • Undo and remove the bolt and top cap.
  • Remove the stem and either flip it or replace it with a different one.
  • Replace the top cap and bolt. Don’t over tighten the bolt as this might damage the headset bearings.
refitting bolt and cap on ahead stem
  • Remove the stem plate.
  • Attach the handlebars to the stem and refit the plate.
  • Position the handlebars and tighten the plate bolts. If you’re not sure how to position the handlebars our article here will guide you through this process.

You can also watch our video tutorial here:

If you want to find out how to tighten handlebars correctly using a cross pattern then check out our article here.

You can also follow the step-by-step process in our video tutorial here:

  • If the cables stop the handlebars from being reattached, then find out which cables are too short and loosen  them so that you can fit the bars in place.
  • Align the bars with the front wheel and tighten the bolts on the side a bit at a time. If you have a torque wrench then tighten them between 5 and 6 NM. If you don’t have a torque wrench then just make sure that they’re tight.  
  • Replace any of the cables that are too short. Our article here will guide you through the process of gear cable replacement.

You can also watch our video tutorial here:

  • We’ve written a great article here on how to replace brake cables.

You can also find some help in our video tutorial here:

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