Landing gear isn’t meant to be perfectly rigid, and that surprises some flyers who assume “stiffer is always better.” In reality, a certain amount of controlled flex is doing useful work every time you land.
When your model touches down, the gear leg absorbs a portion of the vertical energy by flexing, rather than transmitting all of that shock straight into the fuselage mounting points. This is the same principle full-scale aircraft undercarriage legs use, just without the oleo struts and hydraulics — a well-designed carbon fibre leg uses the natural spring properties of the laminate itself as a simple, maintenance-free shock absorber.
The trouble comes when flex crosses from “designed-in” to “developing damage.” A small amount of consistent, symmetrical flex under load, with the leg returning fully to its original shape, is normal and expected. Flex that’s asymmetric between the two gear legs, flex that doesn’t fully recover, or flex accompanied by any audible creak or crack, are all signs the leg is being stressed beyond its intended range.
This is also why gear sizing matters so much (see Day 1) — a leg designed for a lighter model, fitted to a heavier one, will flex more than intended on every single landing, accelerating fatigue long before any single landing looks dramatic enough to worry about.
If you want a rough real-world check, watch a landing on video in slow motion occasionally, or have a friend watch from the side. A small, even flex and rebound on both legs is exactly what you want to see — anything that looks lopsided is worth a closer inspection on the ground.
Our Carbon undercarriage for 50 size – 90 size profile models. is a good reference point if you’re shopping around.