How to Pressure Bend Motorcycle Exhausts

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Customized motorcycle exhausts are not the easiest project for most DIYers. However, if you have the right equipment and are very careful and able to pay attention to detail, it is something some DIYers may want to consider doing to save a lot of money versus having the customized pipe created in a machine shop. This how-to guide will walk you through the steps involved in pressure bending customized bike exhaust pipes. Let's get started.

What You Will Need

Thin exhaust pipe

Thick squash pipe

Nut and bolt

Builder’s sand

Oven or other enclosed heat source

Metal saw

Angle grinder





Clamps or vise

Flame Torch

Square edge

Measuring tape



Wire or Sheet Metal

Step 1 - Design Your Exhaust Pipe

Before you begin, you need to sit down and create a sketch with the measurements and design for your new exhaust pipe. Better still, you might want to construct a model of your new pipe. Either way, this will help make bending a modified or customized exhaust pipe much easier.

Step 2 - Create a Squash Pipe

Next, you'll need to create a squash pipe. To do this, make sure that the ends of the pipe are square. Then, take a nut place it face down on the flat surface. Then, center the squash pipe directly over it and use a welder to create a spot weld to connect the nut and squash pipe. Finally, screw the bolt into place.

Step 3 - Prepare Bending Pipe

Take your thin metal exhaust pipe and place it on a flat surface. Then, use the wooden mallet to strike it until it is flat. Alternatively, you can use a vise grip to flatten the end of the exhaust pipe as well.

Step 4 - Join Squash Pipe and Exhaust Pipe

Take the welder and weld the squash pipe to the open area of the exhaust pipe. Then, fill the exhaust pipe with some sand by passing it to the area where the nut is installed on the squash pipe. When doing this, make sure that the sand is completely dry or it will create steam when the pipe is heated. Steam can rupture your exhaust pipe. After you pour some sand, use something to tap it down and make it tight. After the pipe is full, completely close the bolt on the squash pipe.

Step 5 - Heat and Bend Pipe

To achieve the best results, you should heat the newly created tube in an oven. After the tube is hot, remove it and use a gas torch to heat the metal on the exhaust pipe until it is glowing red. Then, slowly start to bend the pipe. As you bend the pipe, pull on the outer edges of the pipe to keep it from kinking or bending too much. Refer to your drawing are sketch as you bend the pipe to make sure the bends are in the right places.

Step 6 - Cut and Clean

After you bend the pipe, allow it to cool completely before continuing. Then, use a hack saw to cut off the squash pipe and then drain the sand. Clean the exhaust pipe thoroughly and use a file or grinder to clean up weld points.