Use Bondo Fiberglass Mat for Motorcycle Baffle Repacking

Written by william machin
  • Share
  • Tweet
  • Share
  • Pin
  • Email
Use Bondo Fiberglass Mat for Motorcycle Baffle Repacking
Repack the baffle to quiet your sport bike or dirt bike. (Jupiterimages/ Images)

Motorcycle baffle packing has a way of progressively degrading from the effects of heat and moisture. The bike becomes louder to the point where you have to coast it home or risk annoying the neighbours. Repacking the baffle with stock material quiets the bike for a while. A long-term solution is repacking with Bondo fibreglass mat. Fibreglass mat is moisture resistant and the density provides ample sound reduction. Bondo fibreglass mat is found in the paint or auto body section at most hardware and home centres. Park the motorcycle and let the exhaust pipes cool completely to repack the baffle.

Skill level:

Things you need

  • Phillips- or Allen-head screwdriver, depending on your bike
  • Work table or bench
  • Latex gloves
  • Medium steel wool
  • Bondo fibreglass mat
  • Fabric shears
  • Masking tape
  • 1/8-inch diameter nylon cord
  • RTV sealant

Show MoreHide


    Take Down

  1. 1

    Remove the tailpipe cap screws near the end of the tailpipe. Depending on your exhaust, the screws may be Phillips- or Allen-head. Pull the cap off the tailpipe. Pull the baffle out of the tailpipe and place it on a worktable or workbench.

  2. 2

    Disassemble the baffle by pulling the insert out of the tube. Some baffles have a cap that you pop off with the butt of a screwdriver handle. Others have a threaded cap. Pull the baffle out of the tube.

  3. 3

    Wear latex gloves. Remove the stock packing and steel wool from the baffle. This may require some diligence and muscle to remove the old material. Take your time and do a thorough job.


  1. 1

    Wrap a 1/4-inch thick layer of medium steel wool around the baffle. Make sure the steel wool seats against the lip at the front of the baffle. Mold the steel wool by hand to create a uniform surface.

  2. 2

    Cut a piece of Bondo fibreglass mat that covers the steel wool wrapping from end to end and wraps around the baffle twice. Cut the mat using fabric shears. Do not attempt to cut the fibreglass with a utility knife or you will end up with frayed edges.

  3. 3

    Pull two short strips of masking tape off a roll and stage them nearby. Wrap the fibreglass mat tightly around the baffle. Use the strips of tape to hold the wrap in place temporarily.

  4. 4

    Cut a piece of 1/8-inch nylon cord 36 inches long. Start at the back end of the baffle and wrap the cord around the fibreglass mat as you work your way to the lip of the baffle. The wraps should be 1/2-inch apart and snug, but not tight. Remove the strips of masking tape as you go.


  1. 1

    Hold the last wrap of the cord and lip of the baffle with one hand. Let the tag end of the cord hang freely. Insert the end of the baffle in the tube and push it inside. Stop 1/2 inch before the baffle is fully inserted.

  2. 2

    Hold the baffle tube with one hand. Pull the wrapped cord out of the tube. Push the lip of the baffle tightly against the end of the tube.

  3. 3

    Apply a bead of RTV sealant around the rim of the baffle. Insert the baffle into the tailpipe. Reattach the tailpipe cap using the saved screws.

Don't Miss

  • All types
  • Articles
  • Slideshows
  • Videos
  • Most relevant
  • Most popular
  • Most recent

No articles available

No slideshows available

No videos available

By using the site, you consent to the use of cookies. For more information, please see our Cookie policy.