Mine went in the bin after one ejection too many caused the bottle to puncture. I thought it was the perfect product for having on the cross bike for training and warm ups, but ejections were frequent, as @biarittz can confirm, as he ran the bottle over once. The bastard.
I've observed that the more you tighten the bolt the fatter the "stem" of the mushroom shape becomes, and of course the "cap" is closer into the tube, so I'd say there's a good amount of scope for tuning how tightly they hold the bottle.
Mine went in the bin after one ejection too many caused the bottle to puncture. I thought it was the perfect product for having on the cross bike for training and warm ups, but ejections were frequent, as @biarittz can confirm, as he ran the bottle over once. The bastard.