How to Build Your Own Motorcycle Exhaust Baffles

by William Machin
Motorcycle exhaust baffles reduce noise and create back-pressure.

Motorcycle exhaust baffles reduce noise and create back-pressure.

Motorcycle exhaust baffles serve two purposes: Reduce the noise from wide-open exhaust pipes and create back-pressure in the exhaust system. Limiting noise emission is not only considerate, but is required by law in many localities. Those with knowledge of motorcycle engines also understand a certain amount of back-pressure is needed to avoid damaging a stock engine. Baffles are not complex pieces of equipment. Typical baffles consist of steel tubing with a series of offsets that combine to reduce noise and create that necessary back-pressure. You can make motorcycle exhaust baffles in your workshop with shop tools.

1. Measure the inside diameter of the motorcycle tailpipe. Obtain a short length of steel tubing that has an outside diameter 1/16-inch less than the inside diameter of the tailpipe. The overall length of the steel tubing depends on the number of baffles you intend to make. Typical baffles are 8 inches long.

2. Secure the steel tubing in a bench vise and cut an 8inch baffle using a hacksaw. Mark the baffle for three offsets using a felt-tip marker. The first offset is 3 inches from one end. The second is 1 1/2-inch from the first mark. The third offset is 3 inches from the first mark.

3. Secure one end of the baffle vertically in the bench vise with the offset marks above the vise. Make horizontal crosscuts halfway through the baffle at each of your marks with a hacksaw. Reposition the baffle in the vise if necessary as you go. Remove the baffle from the vise.

4. Place the baffle on the workbench with the hacksaw cuts facing up. Secure the baffle in place using one or more c-clamps.

5. Position the tip of a cold chisel at the first hacksaw cut. Strike the cold chisel with a mallet to force the outer edge of the cut into the center of the baffle. Repeat this at the remaining hacksaw cuts to create the baffle offsets.

6. Secure the baffle in the vice with the 3-inch end of the baffle extending from one end of the vise. Chuck a 3/16-inch drill bit in an electric drill. Drill a hole 1-inch from the end of the baffle and through both walls of the baffle. The hole is used for a stainless steel bolt that holds the baffle in the tailpipe.

7. Mark and drill a 3/16-inch hole through the tailpipe that aligns with the bolt holes in the baffle. Once installed, the outside end of the baffle should be flush with the end of the tailpipe. Secure the baffle in the tailpipe with a 1/4-inch diameter stainless steel bolt, lock washer and nut. The length of the bolt depends on the outside diameter of the tailpipe.

Items you will need

  • Steel tubing
  • Bench vise
  • Hacksaw
  • Felt-tip marker
  • C-clamp
  • Cold chisel
  • Mallet
  • Electric drill
  • 3/16-inch drill bit

About the Author

William Machin began work in construction at the age of 15, while still in high school. In 35 years, he's gained expertise in all phases of residential construction, retrofit and remodeling. His hobbies include horses, motorcycles, road racing and sport fishing. He studied architecture at Taft Junior College.

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