My hiking poles have started making an odd, springy noise with every step. The noise sounds like the poles themselves are vibrating each time I plant them into the ground, and it starts about an mile or two into a hike. The poles work well, but this noise is slightly alarming. Is something in the poles about to give?
Information that may help:
I'm using a pair of Black Diamond trail ergo cork poles. They're aluminum, the locking mechanism is the latch/pressure type, and they don't have shock absorbers. I usually extend them to about 115cm. My usual hiking stride is a short nordic walk, to give me speed while supporting my knees a little.