I bought a Harbor Freight motorcycle carrier on sale for my 2022 Honda Grom motorbike. After placing it on my vehicle it stuck out past the sides of my vehicle and was larger than I needed for my Grom. This is when I decided to modify it so that it did not stick out past the sides of my vehicle and make it a better fit for the Grom.

Weighing the front and rear of the Grom I attempted to balance the weight of the bike as close to center as possible on the carrier without extensive modifications.

Supplies

HAUL-MASTER 400 lb. Receiver-Mount Aluminum Motorcycle Carrier (62837)
3/16" Rivets

Step 1: Disassembly

To begin we need to remove parts from the carrier using the next 3 steps. Refer to the image above for pieces that will be removed.

Step 2: Remove Wheel Clamps and Reflectors

Remove the wheel clamps by removing the 2 bolts for each clamp. Remove the reflectors by removing the screws. The reflectors and screws will be reused later.

Step 3: Removing End Pieces

Loosen but do not remove the 4 bolts at the very end of the carrier. Remove the end pieces by removing the 4 bolts inside the rails. You will need to reuse the end pieces and bolts later.

Step 4: Removing Cross Members

Remove all but the 3 center cross members by drilling out the rivets from the underside of the carrier. Be sure to only drill into the rivets and not the carrier frame. After the head of the rivet is removed, use a punch or screwdriver to remove the rest of the rivet. Once the rivets have been removed, slide the cross members out each end of the carrier. You will need to temporarily remove the bolts on the support straps to slide out the inner cross members. Again, refer to the image in Step 1 to be sure of items to be removed.

Step 5: Cut the Carrier to Length

Referring to the dimensions in the image above, trim the ends of the carrier to length. I used a miter saw with a metal cutting blade but other cutting methods could be used.

Step 6: Templates

Using scrap pieces of aluminum or other suitable material, create templates to drill holes for the cross members and end pieces. Use the existing carrier holes to mark the templates before drilling. Drill the holes in the templates using the same size drill bit as the existing holes.

For the cross member template, mark the center point between the holes on each end of the template. For the end piece template make sure the holes align to the end of the rails like the original ends.

Step 7: Reassembly

Referring back to the dimensions in Step 5, drill holes for the cross members and end pieces using the templates created in Step 6. Note that the dimensions for the cross members are to the centerline of the cross members. The cross members are attached using 3/16" rivets. I would recommend stainless steal or aluminum rivets to prevent rusting.

The end pieces are attached using the original bolts. When installing the end pieces, make sure that the angled brackets that hold the end pieces are slightly recessed inside the carrier rails. This way you get a snug fit when tightening the bolts on the end.

I installed reflectors on the ramp so they would be easily visible. Using a reflector as a template, pre-drill holes slightly smaller than the diameter of the original screws. Use the screws to attach the reflectors.

Step 8: Summary

Because stabilizers supplied with the carrier did not fit my hitch receiver I used a "Curt Anti-Rattle Kit for Hollow Shank Accessories" to prevent the carrier from moving. I used ratcheting straps attached to the front forks and rear foot peg brackets. The carrier seemed solid and experienced very little movement while traveling.

Be sure to use straps that are in good condition and can handle the load. There are videos online on that demonstrate how to properly secure your motorcycle.