This is a mounting to hold the bullet-camera in the chest, fastened to the strapes of backpack.
Here you can see more datailed photos
I had use a plastic flexible plate fixed with four pegs to the main straps and chest strap of a Camelback Lobo. The plastic plate is stiff enough for screwing the aluminium support of the cam.
As usual in my systems with bullet-cam, I use a clip of bicycle pump to hold the camera.
Vibration and shaking on resultant video are more intense than in the helmet mountings, and tilt position is difficult for to decide: the tilt for climbing is notably differenced than tilt for downhill. But, except for to put on the backpack, is the more confortable system.
La caja del diablo from montonm on Vimeo.
This is a video recently recorded by Yolucas in Andorra (Pyrenees), just when the pack begins to getting dust on its shelves. The chest position is the best for a inexperienced cameraman: You simply might forget about recording, but movie will be pretty good.