Fork Oil

Add Fork Oil

Motorcycles contain two forks that work as shock absorbers. The rear fork is connected to the steering head; the front fork is set a few inches in front of the rear fork. The forks are responsible for compression damping and rebound damping. Compression damping refers to how well shock is absorbed when a bike hits a bump or hole in the road. Rebound damping is the slowing of suspension springs after a bump in the road has been hit. Fork oil needs to be changed in motorcycles every 18,000 miles to keep the forks working properly.


1. Remove the front wheel.

2. Remove the brake caliper and fork guards.

3. Pry the triple clamps apart with a small, flat screwdriver and slide the forks out.

4. Wipe the forks clean and set them to the side.

5. Take the cap off of the outer tube. Slide the tube down. Turn the fork upside down over a bucket so it can drain.

6. Take the fork cap off of the piston rod. Use a 17mm wrench to hold down the lock nut under the cap. Pull the spring and rebound adjuster out and wipe them with a clean rag.

7. Secure the bottom of the fork in a soft jaw vice.

8. Pull the piston rod out of the fork and continue to pull it out.

9. Undo the adjuster bottom of the fork tube with a 14mm Allen socket and air impact gun. The cartridge should slide out of the fork tube.

10. Dump the oil inside the cartridge into a pan.

11. Clean the old oil and debris out of the inner tubes an cartridge with contact cleaner.

12. Wait for the parts to dry. Then put the outer tube back into the vice.

13. Put the cartridge inside the tube and tighten the compression adjuster into the fork.

14. Stand the tube up. Insert adjuster rod and fill it with fork oil.

15. Put the spring back in once the oil has set.

16. Put the cap on and place it back onto the bike.