gogogo said..
Noticed naish makani variable was recommended. I own two, one an older model, the other a newer model. In my opinion they are both flawed. The older model twists, and the new model collapses with too much force. I personally will not be buying another makani.
I've got an adjustable Makani. I fixed the slipping issue (which wasn't a big deal) by sticking some clear selleys duct tape down the outer faces of the extension (i.e. not in the slots). This gives the clamp something to bite/grip into. Has been solid as a rock ever since and no slippage. Highly recommend it.
I snapped two Makani extensions but the upgraded extension (assume is on new paddles) appears plenty strong enough and I'm leaning on it heaps surfing and its doing fine.