I have done that before angled it too low. I think that weird noise is the camera moving slightly in the case put something in there to wedge it in. Another tip if you have 2 back doors for the case, ones waterproof and others got holes, use the holes one get better sound. Can you take moto trials on that quarry?
Just tried a wipperman connex 100, absolute shite, around 15 stiff links, stretched loads. Going back to a BSD forever chain, ran one for about 6 months, hardly stretched, and is a thing of beauty, black and really nice looking pins.