On Monday, March 26, 2018 at 3:30:07 AM UTC-6, Siggi Ingason wrote:
Hi, does anyone know what kind of hub the Pik20d trailer has, as we
need to replace a spring and a few other parts for the auto reversing
mechanise?

Thanks
Siggi

Siggi,
Could you be more specific? Is this a trailer manufactured by PIK or is it a trailer that is used to tow a PIK 20? One thing to consider is that many trailer manufacturers used standard off the shelf running gear. For example Cobra uses hubs, wheels, etc., that are sold through AL-KO. I once owned a Bickle trailer that used all standard US hardware sold through the local trailer and RV supply outlet.
Take a close look at the hub that is on the trailer and check for a name of a manufacturer (Usually in the form of a stamp) somewhere on the mounting plate and there could even be a part number to make things easier.
I don't know where you are located but in North America a company called Dexter bought out AL-KO and all of their inventory.