Those early season team rides are often the first time coaches get an on-the-bike look at their riders after the long break. You may have noticed that with feeding and watering, there is tendency to grow. Speaking broadly, and as a parent, it can be hard to notice the difference day-to-day. But a coach that has not seen a rider for some months notices the sprouting! Let’s review just one aspect of fitting those longer legs; moving the seat post up up up.
First, a comment on raising saddles. You sometimes hear about moving saddles up a little at a time. Don’t worry about that, just move it. These are not “pro road riders”, the proverbial snowflakes of the biking world (...being one myself). If your rider is 2-inches too low, move them up 2-inches, now. They will be fine, their knees will be fine, their muscles fine, their life, just fine. You are unlikely to have the time to creep up ¼”, eight different times on a schedule. Move ‘em up.
Now to the mechanical part of this. The seatpost is a “slip fit” inside the seat tube. The post should be smaller than the frame by 0.1mm, or that is the idea. Most seat posts are made to tighter tolerances than the frame. Especially for steel and aluminum frames, that is a hard target to hit. Complicating this are the different surface finishes of the post and inside the frame, plus any grease, grit, and dirt inside. Then the frame and post material itself will affect how the post is grabbed. All of this can make manufacturers torque settings more of a suggestion than an exact science.
Assuming the seat post is correct enough for the frame, this typically not an issue. Seatpost fasteners needs to be tight, but not “killer tight”. Generally all you need is enough squeezing (torque) to keep the seat from turning side to side. Here’s a useful test standard. Grab the saddle nose and try to twist it side to side with one hand. If it cannot be moved side to side, it is not going to slip down into the frame, and you are tight enough.