Condensed answer: Technically, a pipe cutter can cut carbon bars, but the practice isn’t recommended because the handlebars can be damaged in the process. It’s better to use a fine-tooth hacksaw blade with a guide.
How Can a Pipe Cutter Damage Carbon Handlebars?
Carbon has poor resistance to clamping force/compression which is why it’s necessary to use a torque wrench when dealing with carbon components.
The torque wrench measures the power input and prevents overtightening that can crush a carbon bar or a seat post for example.
In order for a pipe cutter to operate properly, it has to squeeze the bar. Since there’s no torque reading available, it’s technically possible to exert too much compression force onto the bars and damage them.
The outcome isn’t guaranteed, though.
2. Delaminated Carbon Layers
Pipe cutters have a V-shaped blade that digs into the bars. As a result, some of the carbon layers disconnect from one another because they’re aren’t cut evenly. The outcome is a poor cut with splinters.
Best Tools For Cutting Carbon Handlebars
The standard way of cutting carbon bars and steerers is a hacksaw with a high teeth density blade – most manufacturers recommend a blade with at least 28 teeth per 1 inch (28TPI).
The greater number of teeth ensures a smoother cut which is a necessity when cutting carbon as its layers can delaminate from one another very easily.
It’s also useful to have a saw guide that will ensure a straight cut.
Tip 1: Cover the area with masking tape. The tape presses the carbon fibers into their beds and minimizes splintering.
Tip 2: Periodically apply soap water on the cut to prevent the spread of carbon dust into the atmosphere.
Tip 3: If you don’t have a saw guide, you can use two pipe clamps. They don’t work as well as a dedicated guide but are better than nothing. You shouldn’t overtighten them to avoid damaging the bars.
Rotary Tool (Dremel)
Another option is to use a rotary tool (e.g., Dremel) with a diamond cutting wheel. The downside of this approach is that it’s close to impossible to make a super straight cut because there’s nothing to guide the wheel.
Tip: The rotary tool rotates at high speeds and will instantly spread carbon dust into the air. Breathing carbon dust is bad news for your lungs. Therefore, it’s highly recommended to wear a protective mask when relying on this method. The mask has to be able to stop at least 3-5 micron particles.
FAQ: Can all carbon bars be cut?
The purpose of cutting a handlebar is to make them narrower. Thus, bar cutting is reserved for flat bars.
That said, some bars aren’t meant to be shortened because cutting them would force the rider to move the shifters and brake levers inward.
This could be problematic because on some bars the area where the shifters and levers mount is reinforced to increase the resistance to compression. When you move the bars away from that segment, they will go onto a non-reinforced area.
Ultimately, however, this isn’t the case for most bars. If the bars have measuring indications at the ends, then the manufacturer has intended for them to be cut.
FAQ: Can I use a pipe cutter on metal bars?
Yes. A pipe cutter is fine for cutting alloy handlebars as they have a much greater resistance to compression. Some prefer this method when cutting aluminum bars because it’s quick and leaves a nice cut.
Kind reminder: You’ve probably heard the saying “Measure thrice, cut once.” It applies here too. Before cutting, make sure that the math is right. Don’t forget that the total amount of reduced length has to be divided by 2 to find out how much to remove from each side.
For example, if you have 780mm bars and want to get them to 720mm, you need to remove approximately 60mm total. This means that you have to cut 30mm from each side.