How to Change a Seat Post for a Road Bike

How to Change a Seat Post for a Road Bike
Road bike seat posts are used to connect the seat, or saddle, to the rear upright tube of the bike. Seat posts are made of various materials including steel, aluminum and carbon fiber. The seat is mounted to the post by a mounting bracket which holds the seat in position at an angle. The post fits into the upright tube of the bike and is secured in place by set screws. Changing the seat post is often done because of wear or as an upgrade.


Difficulty: Moderate

Things You’ll Need:
  • Replacement seat post
  • Allen wrenches
  • Adjustable wrench
  • Ruler or calipers
Step 1
Loosen the seat post. This will typically require two set screws to be loosened with an Allen wrench. The screws are located at the top of the bike frame upright tube. Turn the screws to the left or counterclockwise.
Step 2
Twist the seat and post slightly and pull straight up. It may be necessary to initially break the post free from the upright tube because of minor corrosion. Remove the seat and post and set aside.
Step 3
Measure the inside diameter of the road bike upright tube. Determine the diameter of the replacement post tube. Use a ruler or, for more precise measurements, an adjustable caliper. Also measure the outside diameter of the post that was removed.
Step 4
Purchase a replacement seat post for the road bike using the measurements from the upright tube and old seat post. Bike shops as well as online retailers and manufacturers offer posts for sale in variety of materials, including carbon fiber.
Step 5
Remove the seat from the old seat post by loosening the retaining bolts from the seat mounting bracket. Use an Allen wrench or adjustable wrench as needed. Take note of how the seat is attached and centered to the post.
Step 6
Attach the seat to the new post and roughly position the seat based on the old setup. Secure all retaining bolts. Insert the new bike post into the upright tube of the bike and tighten the retaining screws.

Tips & Warnings

Make adjustments to the post height as well as seat position by sitting on the bike. Make incremental adjustments until the seat and height are comfortable.
Make sure all screws and bolts are securely tightened to avoid possible injury.

Article Written By Keith Dooley

Keith Dooley has a degree in outdoor education and sports management. He has worked as an assistant athletic director, head coach and assistant coach in various sports including football, softball and golf. Dooley has worked for various websites in the past, contributing instructional articles on a wide variety of topics.

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