There are several manufacturers selling folding/collapsible poles, usually for hiking or splitboarding. Are they also suitable for cross-country skiing?
There aren't any x-country specific adjustable poles because there are no real benefits.
- The skis will always be longer than the poles.
- Unlike hiking or splitboarding, scenarios where you need to stow the poles but not the skis don't exist for x-country skiing.
- It adds weight in a sport where weight is a big factor.
- Unlike hiking and skiing, double polling, where maximum force is applied to poles, means the risk of poles collapsing (losing length) is significant and detrimental to performance.
- A single shaft will transfer more force than a double shaft.
Currently available collapsible poles are mostly too short for the long stroke necessary in cross-country skiing, and probably wouldn't stand up well to hours of double polling.