A variety of factors may lead to your TRS+ post not returning to full height every time. Here's some things to try:
Problem: Seatpost cable is too tight, so the release mechanism can't fully release
Solution: Thread the barrel adjuster on the seatpost lever in until the lever can move freely a small amount before tension is applied to the cable. Try actuating the post and verify that it will lock in the fully extended (up) position.
Problem: Seatpost clamp is too tight, and is compressing the upper bushing in the seatpost causing drag in the seatpost movement
Solution: Loosen the seatpost clamp screw a few turns, then check to see if the seatpost reaches full height. If so, tighten the seatpost clamp just enough to keep the seatpost from sliding in the frame under rider weight.
Problem: Seatpost cable binds in the housing, and the release mechanism won't fully release
Solution: Ensure that the cable is sliding smoothly thru the housing. Some bikes have tight bends in the internal routing which if care is not taken during install may kink the cable and housing and cause return issues.
Problem: Contamination in the upper seal or bushing cause the post to stick
Solution: Did the issue arise after some particularly dry and dusty or wet and muddy rides? Try unthreading the main seal collar counter clockwise using your hands or a strap wrench. Slide the collar up, clean and lube with some light teflon based lube like Tri-flow.
Problem: Certain V10, V11 or V12 Seatposts were shipped with a light spring for easy actuation. Over time, the spring loses force, and won't return the seatpost to full height.
Solution: First identify the version of seatpost you have. Reference the laser etched production code near the max height line of the post. You will need to loosen the seatpost clamp and slide the post out of your frame a little ways to see this info. Look for the string of alphanumeric characters that look like this: 24JV10SC1.
If you have V10, V11 or V12, it is possible the solution will be to replace the springs with stronger updated versions. We will send you these free of charge. This should fix your issue.
If you have V13 or higher we will need to get some more specifics to work thru the problem with you. Please reply to us with the below info so we can diagnose and start addressing the problem.
For Posts with this issue, please submit a warranty form here: Warranty Request Submission Form