Since moving to a residential street with no garage I have been parking my SD outside the house in a small private area in front of the house. Like many UK terraced properties you can just about get the bike through the gate and do a sort of 5 point turn to get in (and about double that to get out backwards again ) But at least it's on my doorstep and convenient for using everyday. I've got two Almax chains and massive locks as well as a disc lock from my days in London but I want to put in a ground anchor so the whole bike is attached to the ground and can't be simply lifted into the back of a van.

In London I bought one of those Y shaped ones which was brilliant but I literally had to hire a pneumatic digger to create the hole big enough to sink the thing into the ground and then a load of cement to fill it up again. But here is rented property and I don't think I can do a hole that big. The surface is concrete but I don't think it's very thick and the surface is crashed and broken up. I could get a cheaper bolt down anchor but I'm worried that a determined thief could just smash up the layer of concrete around the bolts pretty easily.

I'm wondering if anyone knows of an anchor that you bury deep but the hole doesn't have to start of being two feet wide? Obviously I'm searching the net but someone might know the ideal solution.

Any thoughts or recommendations?

Mate, if a thief is that determined, it don't matter what security u have.
I have one of them bolt down anchors, would be easier to cut the metal hoop then trying to Smash the concrete to get the bolts out.

Move

I think if it was me I'd have that small small red slab out, dig down and make a small but deep pit from there and concrete something in that. To be doubly secure you could attach something to the wall at the front too.

Top tip that I got told once was to position any anchor so that when in use there is the minimum slack in chains. The closer they are to the bike the better, if there's zero slack to move the bike away before going to work on a lock or anchor, the harder it is for the scumbags.

Gotta love living in the states. I have a motion light over where I park my bike, and a gun. Going to jail/hospital if you try and rip my off.

In addition to Everything suggested, get a simple wireless security camera direct to the phone. My dog was great security!

Fill a big bucket with concrete and sink a suitable shackle, or a short length of almax into into it. It'll probably be better then trying to attach into thin concrete.

Just don't accidentally put a proper cartridge in it lol.

Got the first stage done for a Y type anchor that you bury in the ground with concrete.

After My Ducati and coworkers Harley had been stolen from in front of work, we installed a 4'x8'X1/4" thick steel plate that we welded heavy hardened steel chain loops to to act as an anchor for our own. We parked on the plate. I used a Cobra-links through the frame and never had another problem. May be a bit extreme but it was a bad neighbourhood. It was removable if need be.