DIY Frame Straightening for a Motorcycle

Straighten a motorcycle frame in your home workshop.

Motorcycle frames are designed to support the engine, drive train and steering headset in a precise alignment. Most frames are fabricated from aluminum or steel tubing that is vulnerable to damage from certain types of spills and impact. Frame shops use sophisticated metal jigs to straighten and true bent frames. If the motorcycle frame is seriously bent or a weld is cracked, enlist the services a frame shop to straighten and align the frame. A do-it-yourself mechanic can straighten minor bends in a frame using basic shop tools. Straightening a motorcycle frame is done with the engine, gas tank, wheels, suspension and all accessories removed down to the bare frame.

Things You'll Need

• One sheet 3/4-inch plywood
• Duct tape
• 1 1/2-inch radius half-round steel pipe
• Hacksaw
• 1 1/2-inch pipe brackets
• 1 1/4-inch wood screws
• Power drill with screw tip attachment
• Steel mallet

Instructions

1. Place the motorcycle frame on a sheet of 3/4-inch plywood with the bent section down.
   Put several strips of duct tape along the upper side of the bent section to prevent scratching the finish.

2. Cut a length of 1 1/4-inch radius half-round steel pipe that spans the bent section and overlaps onto the straight portions at each side of the bend. Cut the piece of pipe to length with a hacksaw.

3. Place the half-round steel pipe atop of the bent section of the frame. Secure the ends of the pipe and the frame to the plywood with 1 1/2-inch pipe brackets and 1 1/4-inch wood screws. Drive the screws with a power drill and screw-tip attachment.

4. Straighten the frame by striking the half-round steel pipe with a steel mallet. Check the gap between the underside of the bend and the plywood as you go. Stop when the underside of the frame is flat against the plywood.

5. Remove the pipe brackets and the half-round steel pipe. Remove the strips of duct tape. Inspect the repaired section of the frame by sighting along the frame tube. If necessary, repeat the steps and fine-tune the bent section of the frame.

Tips & Warnings

• Cut out small sections of the half-round pipe to fit it over engine mounts or other mounts on the frame.

• Sight the bare frame from all angles to determine if alignment was affected. If necessary, have the frame trued and aligned by a frame shop before reassembling the motorcycle.

References

• Best-Motorcycle-Gear: Motorcycle Frames
• Frame Straight Systems: Motorcycle Wheel and Frame Repair
• Knuckle Buster, Inc: The Frame Jig