How To Install Your Bike Seatpost

There are a variety of reasons why you may want to install a new seatpost. If you’re trying to turn your road or mountain bike into a lithe climbing machine, swapping in an ultra-light seatpost is a quick and easy way to slightly reduce overall weight.

Mountain bikers may also want to try a dropper seatpost. These handy devices allow you to change saddle height on the fly, meaning you don’t have to stop to lower your seatpost at the beginning of a tricky, technical descent. And when you get to the bottom of the trail, the same flick of a switch will raise your saddle back to normal riding height. Whatever your motives, here are the basic steps to installing a new seatpost:

  1. Before removing your old seatpost, measure the height and fore-aft positioning of your saddle. Do this by taking a standard tape measure and measuring from the middle of the bottom bracket to the top of your saddle, and from the tip of your saddle to the end of the stem. Write these numbers down.

  2. Using a properly sized Allen wrench, slowly loosen your seatpost clamp bolt and pull out the old post. Once it’s removed, find the size indicator number on seatpost. This number represent the post’s diameter in millimeters. Your new post must be the exact same size or it wont properly fit in the bike seat tube. Also remove your saddle from the old seatpost and then install the saddle on your new post.

  3. Before installing your new properly sized seatpost, lightly grease the inside of your seat tube or the exterior of your new seatpost. If your new seatpost is made from carbon fiber, you’ll need to use a special carbon fiber paste, which helps hold the post in place and decreases the amount of clamping force required.

  4. Slide your new seatpost into the seat tube, then tighten the clamp bolt until its snug but you can still slide the post up and down. Now adjust the saddle to the correct height, and then finish tightening the clamp bolt to correct manufacturer torque specs. Now adjust the saddle’s fore-aft position until it matches the number you wrote down in step No. 1.

  5. Finally, with the proper Allen wrench tucked in your jersey pocket, head out for a short shakedown spin to make sure your saddle is in the correct position. If necessary make additional up-down, fore-aft or height adjustments.


If you have any questions about seatpost installation, call the Performance Bicycle Spin Doctor product support line at 1-800-553-TECH. Happy riding.


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