
I've always had my 2 'decent' bikes secured in the garage, to wall anchors, but when I got a third 'decent' bike there's not enough wall space for another, so I opted for a 'portable' ground anchor, which is a D lock set in a bucket of concrete which I lock my bike to.
Indeed , i had thought about that but opted to buy some ground anchors instead which i have half a mind to do the same instead of cutting holes in the shed base.That is a great idea... gonna nick that... the idea that isThanks.
Indeed , only trouble is my walls are wood so a ground anchor should be more secure .Only flaw with ground anchors is that they are on the ground. ANY chain can be cut with big croppers but to do so on the real ones requires a LOT of leverage and this is achieved by resting the croppers on the floor and bouncing up and down on them. A chain going up to a wall anchor is [or should be] too high for this and is MUCH more difficult to cut.
That is a great idea... gonna nick that... the idea that isThanks.
Best to use an old bucket, not a brand new one, if you have one around as the concrete doesn't come out once set 
, the bolt has a conical nut with nothing to grip on on top of the normal one so i cant tighten it up unless i cut a fecking massive hole or move the shed so i can get the spanner on it .Tried a socket set and it cant engage the lower bolt .