When using trekking poles with a twist-and-lock locking mechanism, I've experienced slipping (the poles will slightly collapse during use, making you frequently extend and re-lock it). Is there something maintenance-wise that helps avoid this, or is it simply a sign of poorly-made poles?
It does not necessarily reflect poorly made poles. If you have used the poles for a while without problems and you're just recently having problems, they likely need to be cleaned. I would start by checking to see if your poles have maintenance instructions specific to your model. You should always follow the manufacturers advice if possible. If they do not have cleaning instructions, than it's still fairly easy to clean most twist style locks on hiking poles.
Cleaning the poles
Start by pulling the poles apart. At the end of each section, there is a screw with a cap on it. This cap expands as the screw tightens into it causing it to put pressure on the walls of the outside tube preventing it from moving. Clean off the cap if it is dirty, and while you're at it, remove the cap and clean and lubricate the screw as well.
After the screw and cap are clean, use a brush of the correct diameter to clean inside the poles themselves. Make sure there the cap is gripping a clean surface and not just slipping on gunk built up inside the poles. Re-assemble the poles and see if they now support weight when locked.
- Keep the inside of your poles clean. If they get soaked or sandy or muddy, clean them out after your trip and let them air dry.
- Clean the actual lock mechanism occasionally. Depending on the pole type, there may be a rubber cylinder that does the locking, clean it, and consider lightly abrading it with sand paper (not enough to remove any material, just make it rough!).
- Buy replacement locking mechanisms - these are pretty cheap, often $10 or less for everything needed. Makes a big difference!