Im looking to buy a used Trek X-Caliber 9 bike from 2020 used. The seller says he only rode the bike for 150km and the bill shows that he bought it only 9 months ago. Everything looks good so far but I recognized that the shocks look a little bit strange.

enter image description here

Can you tell anything about it? Why are they so bright on the upper inch?

1 Answer 1


looks normal to me. There is oil in the bottom of the fork that lubricates the fork stanchions during use. There are rubber seals that hold the oil in the bottom of the fork, but they are not going to be 100% effective. It is this minute amount of oil you can see on the bottom half of the stanchions and nothing to worry about.

Eventually the seals will wear out and you'll need to replace them, along with the oil in the fork. You'll know that you need to do this when it becomes more than a film and you start getting clumps of dirt and oil together. Keeping everything clean and changing the oil frequently will improve the life of the seals and would recommend at the least to wipe the stanchions after every ride with a clean, soft cloth to remove any dust and dirt.

  • 2
    If your damper oil is showing up on your stanchions, you have big issues.
    – MaplePanda
    Mar 11, 2021 at 15:45
  • 1
    didn't want to overcomplicate any further, but feel free to suggest an edit. I don't know of any specific mountain bike examples but on one of my motorcycles the damper oil and the lower leg oil was one and the same.
    – el_oso
    Mar 11, 2021 at 17:24
  • Bath lube oil is far more viscous than damper oil in most MTB applications. Your motorcycle needs more damping, so the oil will be thicker.
    – MaplePanda
    Mar 11, 2021 at 20:27

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.