Dapol wagon wheels.

[The Sligo Rover]

I have just changed all the wheels on four Dapol wagons that kept derailing on one particular point.
All other rolling stock passed over this point without any problem. I have replaced them with Hornby R8098 8 spoked wheels. Problem solved, it cannot be the back to back distance because the removed Dapol and new Hornby were checked and set with the same gauge. The Hornby wheels are not quite as free running as the Dapol ones but they do not derail.
The replacement Hornby wheels are not cheap at £19.90 for ten.
What is it about the Dapol wheels that keep giving this trouble.

[Rog (RJ)]

I think Dapol wheels have a smaller flange.

[Walkingthedog]

When I ran OO all of my 10 or so Dapol wagons derailed on a particular curve until I changed the wheels. None of my other 90 wagons did the same.