Hey Bought the wheel chock as recommended by @Android853sp and it looks a good bit of kit. However (why is there always a however!) It's to wide to fit the trailer runners. If I turn the "feet"/base inwards it fits fine. Think it will be OK like this? Doesn't effect the working at all, will just be less stable as bolt holes narrowed. I'm intending to fit some metal plates on the underside for more strength. Before and after pics.
I bought one of them the other week. I have the feet turned inwards, it works just fine. It holds the bike upright while strapping down - I wouldn’t rely on it on its own.