Alko locks on twin axles

I'd doubt the jockey wheel could lift the front of a caravan sufficiently to take enough weight off the front axle to allow you to spin a wheel ... 🤔

This issue is where I don't understand how Lock-N-Level bags help. The wheels are still sitting on something, even if it is an airbag.

Richardrjb, if I were in your situation I would be looking for some form of security which is easier to fit than these Alko locks. 

Have a look at the video on their website and all will become clear.

Having seen the video for lock n level is does seem to be a good way to apply the locks. However, it depends on your insurance policy, your intended use of the van (remote or relatively secure club sites) and your attitude to risk. Some insurance policies insists on wheel locks fitted on site, others don't. 

There is an argument that if you are staying on club sites, one lock and perhaps a suitable lock and chain through the other alloy and the chassis will suffice. Some motorcycle products with hardened chains took over 2 minutes to defeat them with an angle grinder. This would probably cause some unwanted attention on site for the thief!

Fully accept that if you are parked in some remote location then you need two locks. This would only tick a box for your claim - your van would still disappear if the thief wanted it.

Personally, I fit one lock and use a bottle jack (£15) to lift the van, spin the other wheel and apply the second lock.