Ground Anchors and what to screw them to...

This might sound a bit daft, and I am pretty sure I can expect some equally daft answers...

My brother has a ground anchor to install and has asked me for a bit of help.

He has a flagged area where the bike is stored so I thought "Easy, just remove a flag, fill a hole with concrete and screw the anchor to that. Job done."

However...how big is big enough for the lump of concrete?

What else shouldI bear in mind?


Cheers

the bigger the hole, the better. imo

Single flag? Pah! Pull up all the flags, then concrete the whole area, wait for it to dry & drill. Then use some very long anchor bolts. I don't have a ground anchor, but living where I do, I can vouch for anchor bolts! Also re-enforce the whole concrete area with steel rods for greater effect.

Just after we moved in, a mate helped me put the satellite dish up, and we put 3 3inch anchor bolts in the wall, with my mate famously saying "That'll hold anything up there!" Granted, it was secure enough for him to proceed to swing off the arm, which he did, and he probably won't like me saying that he's no lean guy!

Comes to the first storm, heypresto, my sat dish is hanging off the wall. So now it's got 8 5inch anchor bolts in, and I doubt it'll move even when I want to take it down.

If you think you've secured a ground anchor, put twice as many bolts in the thing!

Yes, you were right about silly answers, but it's better than my first thoughts. Response to the subject was "the ground"

It's a case of balancing risk against effort:

You could say, if the concrete block takes five minutes to extract from the ground, that'll put off maybe 80% of thieves.

Then you could say that if the concrete block once extracted is too big for two men to lift comfortably with the bike, that'll put off another 10%.

But what about the final 10%? They might have a Kango hammer, they might have ten strong lads handy, they might just saw through the chain, etc, etc

In this case, I'd say remove four flags, dig a decent depth undercut hole and add some metal bars set into the walls/floor of the hole to make it harder to extract the plug of concrete. Make up the concrete using a decent aggregate mix and then set the flags back into it. Then screw the ground anchor all the way through the flags and into the plug. It'll probably be safe enough.

Bolt the ground anchour to the bike, that way you'll always have it handy wherever you are....

[northwind]

A mate of mine... let's say aquired a big metal sheet, the sort they use to cover over holes in the road. Don't worry, he didn't nick it from over a hole Just bolted the anchor to that and parked on top. The thing took 2 people to lift, but more importantly it also had a Vespa parked on top, and it was big enough that you couldn't lift the bike properly without standing on the metal plate. Probably more effective than a concrete block, I think.

You could go further with that idea- lift enough flags to fit it underneath, then lay them back over the top.

The weakest link is probably the chain, have you seen all the snipped ones on the ALMAX chain site? It's quieter than hacking away at concrete too. A nice big hole with three or four bags of ready mixed concrete is probably enough, you can pick it up in B&Q etc, just mix with water, like angel delight haha

Four bags in the hole would mean a weight of about 120Kg when set, which is really flippin heavy. As said above, metal bars help too.

Yea, the chain is the weak link.

What chains does everyone recomend?

And what other mechanical security?

Matt

http://www.yanchor.com/The%20Y%20anchor.html

You could go with one of these if your going to be messing about with concrete.

[northwind]

If you want real security, Almax are pretty much the only choice currently. There's other crop-proof chains now, but most are overhardened which makes them susceptable to specialist attack because they're more brittle. Anything that isn't crop-proof is no better than the cheapest chain you can find, it'll only deter kids. Sold Secure, Thatcham etc are all completely irrelevant for chains, since not one guarantees that it can't be cut with manual boltcutters. This is as ridiculous as it sounds- I wasn't convinced till I took a link off the top of the range Oxford without significant effort using a fairly typical set of Irwin crops.