How to Install and Remove a BMX Seatpost That Is Stuck

There are two common reasons why BMX bicycle seat posts get stuck. The first is due to chemical changes like rust and oxidation. The second reason is because the wrong sized BMX seat post was forced into the frame. Although heat is often used to unstick some metal parts in auto repair, it can be extremely damaging to BMX frames, especially aluminum or carbon-fiber frames. Removing a stuck BMX seat requires leverage, penetrating oil and patience.

Things You'll Need

  • Penetrating oil
  • Allen wrench
  • Socket set
  • Screwdriver
  • Breaker bar
  • Drain cleaner
  • Water
  • Measuring cup
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Instructions

    • 1

      Remove the seat post bolt with an Allen wrench. Slide the bolt out of the clamp; pry the clamp apart slightly with a screwdriver to pull it off the seat post.

    • 2

      Soak the area thoroughly with penetrating oil and allow it to soak in for 30 minutes.

    • 3

      Place the seat saddle over the seat post if it is not attached. Slip the saddle's mounting bolt through and tighten it with the socket set.

    • 4

      Grasp the saddle firmly in both hands and, using it as leverage, try twisting the frame in short sharp jerks to the left and right. Typically, this will break the seat post free.

    • 5

      Remove the seat's saddle using the socket set. Insert a screwdriver through the saddle mounting holes at the top of the post. Slip the breaker bar over the handle of the screwdriver and use it as a lever to work the seat post loose.

    • 6

      Mix a 1/2 cup of drain cleaner with 4 cups of water and carefully pour a small amount into the seat post and frame. If the frame is stuck due to erosion from aluminum oxide -- which is common on aluminum frames -- the drain cleaner will help dissolve it. Once the drain cleaner has soaked in, attach the seat saddle or slip the screwdriver though the mounting holes and work the post back and forth until it comes free.

    • 7

      Allow the inside of the frame's seat mounting tube to dry overnight.

    • 8

      Clean the removed seat post, or replace it with one that is the right size if it is the wrong size.

    • 9

      Attach the seat saddle to either the replacement seat post or the cleaned seat post. Slip the mounting bolt through the saddle and seat post and tighten it with the socket set.

    • 10

      Place a dab of grease into the frame's seat tube. Slide the seat post into position at the desired height.

    • 11

      Put the seat post clamp and bolt into position and then tighten the seat post bolt with the Allen wrench.