Stiff front fork suspension

Discussion in 'Other Service and Maintenance' started by BikeSAG, Sep 16, 2015.

  1. BikeSAG

    BikeSAG Active Member

    2007 FLSTC

    Changed the front fork oil. Did it with bike up on a lift and forks full extended. Added the recommended amount of fork oil weight as recommended by HD.

    Now rides very stiff with little shock absorption. Minor bumps felt through the handle bars.

    Why did this change? How do I correct it?
  2. HDDon

    HDDon Experienced Member Contributor Retired Moderators

    If I remember there are 2 amounts to add, one is if the system is completely dry and the other is if it is just drained. If you added the larger amount it could be that you have too much oil in the tubes. The other thing that might have happened is when you replace the top caps and torqued them down you may have twisted the fork assembly in the trees and put them in a bind.
  3. Breeze3at

    Breeze3at Well-Known Member

    Is it possible that you filled the same side 2 times?
  4. Bodeen

    Bodeen Well-Known Member Staff Member Moderator Contributor

    Not completely familiar with the softail forks. If they are drained from the bottom, did you put the bike on the ground and pump the forks with your weight to get all the oil out?
  5. gator508

    gator508 Senior Member


    Is the oil the same viscosity, there is regular and heavy duty, may contribute to a stiffer ride.
  6. TQuentin1

    TQuentin1 Well-Known Member Staff Member Moderator

    Your factory service manual will probably give you an air gap spec and the process for replacing the fluid. Since you have already changed the oil, follow the instructions for setting the air gap. You don't need the fancy HD tool to do this, just some clear plastic tubing and a baby medicine syringe. Suction out the excess oil using the plastic tubing inserted in the top of each fork tube. Mark the tubing for the required air gap so you can insert the tubing to the right level. Follow the instructions in the FSM wrt up on lift or sitting level on the ground.

    Button it back up and take it for a nice ride. If it is still too stiff, try removing another 1/4 inch of fluid from both sides. Test ride again and repeat if required. If after second time it is still too stiff, you may have to change the fluid again going with a lighter oil. I have an ultra, and I use the HD Type E. Works just fine.


  7. BikeSAG

    BikeSAG Active Member

    Thanks for all the replies and advice.

    It was too much fork oil.

    Removed equal amounts from both forks and that did it. Front end acts like a shock absorber now and has some dive on heavy front braking.