HOW TO TRIM CARBON HANDLEBARS – THERE’S ONLY ONE CORRECT WAY TO DO IT

HOW TO TRIM CARBON HANDLEBARS

Bar width is a commonly disputed topic in the mountain biking community. Some say 800mm is the ultimate length; others swear by 780mm or 760mm, or maybe 765mm. As a result, most bar manufacturers build their bars to a factory length of 800mm or wider, leaving it up to the customer to cut them down to their desired length. All bars can be tricky to trim down, but carbon bars require the most caution. You can’t just take a pipe cutter or regular hacksaw to them willy-nilly. Instead, you must use a more refined technique, which is what we will be demonstrating in today’s “Garage Files.” This process can be done with the bars on or off the bike, but for today we’ll be working as if the bars have already been installed.

NECESSARY TOOLS:

• 2.5mm or 3mm Allen wrench (for grips)

• Measuring device, metric

• Soapy water

• Hacksaw

• Carbon-compatible or fine-tooth saw blade

• Saw guide

• Masking tape

• Sandpaper

• Safety glasses

• Marker

 

 

 

First, you must remove your grips. Most modern grips are lock-on grips that are easily removed with an Allen wrench, usually a 2.5mm or 3mm.

Once the grips are removed, slide all your components inward or take them off completely. It’s best to do this on one side at a time to have a better reference when realigning these components.

Now you have plenty of room to work. We are cutting the One-Up Components E-Bar, which comes standard at 800mm wide with reference points every 5mm on each side for ease of cutting without having to measure. If your bars don’t have those marks, you can use a ruler, typically metric, and a marker or sharp point to mark your cut. Remember to only measure half of your total cutting length on each side of the bar; for instance, we’re cutting 30mm total off the bars, so that’s 15mm off each side.

 

Before we cut, there is one other thing that needs to be done. We will be applying masking tape around the bar starting right where we’re going to cut. This helps keep the bar from splintering when you’ve reached the end of your cut, so it remains smooth and is easier to sand down. You can use any tape you’d like. We use masking tape because it doesn’t leave a residue.

Now, we’ll install our saw guide. Slide it over the bars and line up your mark by looking through the slit that will guide the blade. Check your alignment by sliding the blade through and gently resting it on the bar to make sure it’s going to cut where you want it to. It’s best to cut just outside of your mark to allow for the width of the saw blade. Repeat as needed until properly aligned. Double- or even triple-check your measurements and marks to be sure that you are cutting the correct length off. It’s easy to cut more, but impossible to add any material back later.

Next, we’ll wet the cutting surface. Carbon particles are harmful if breathed in, so you need to keep the dust down. With a spray bottle of soapy water or cleaning solution, spray the cutting surface until it is amply wet. You’ll want to do this once or twice before you get all the way through the bar.

 

Now, it’s time to cut. Carbon blades are not directional in their cutting, so you can just apply pressure as you move back and forth. This should go relatively quickly. Be sure to lighten up your stroke when you get to the end to prevent splintering.

Once you’ve cut all the way through the bar, remove the saw guide and the tape, and sand down the ends until all burrs are gone.

You can then install the grip on that side and reinstall your components. Be sure to use a torque wrench on the brake, shifter or dropper-post lever clamps, because overtightening them can create stress risers that can cause the carbon bars to break.

Repeat this process on the other side of the bars.