Dropper Post Length Calculator
Want to know how long of a dropper you can fit on your bike? With two simple measurements our Dropper Post Length Calculator will tell you.
STEP 1 - Measure Dimension X. This is your current saddle height. It is the distance from the top of the seatpost collar to the middle of the saddle rails.
STEP 2 - Measure Dimension Y. This is the your insertion depth. It is the distance from the top of the seatpost collar to an obstruction in your frame. Measure this distance by inserting a rigid post or tape measure into your frame until it hits an obstruction.
Once you have your insertion depth, you should reduce measurement by 10-15mm to ensure fitment. Depending on the frame design, inserting the dropper at the max depth may cause tight/sharp cable routing, which does not allow for proper dropper post actuation/function.
OneUp dropper posts can all be shimmed by 10-20mm. If a length appears in brackets below your dropper post suggestion, you'll need to shim the post to that length using the included travel pins. Learn more about how to shim your dropper post.
*Please allow the dropper post calculator a few seconds to load, below. The calculator will refresh every 3 minutes to stay responsive while you take your measurements. Always double-check your measurements before ordering to ensure the perfect fit, the first time.*
OneUp Explainer Video
This video explains how to use the OneUp dropper calculator to find the longest dropper post that will fit your bike. You'll learn how to check your dropper diameter and take two key dropper post measurements.
Want a more in-depth description? Access the full-length written guide, How to Know What Dropper Post Fits Your Bike.
