Bart,
why should the pin wear more, as once it's been drifted or pressed into the bore with sufficient grip, there should be no relative movement between those two components?
The interference fit that's needed is only a few thousandths of an inch ( 0.05mm) after all...

ken.

As said I'm not a king pin specialist and wasn't aware of the interferance fit. My dad did his kingpins some years ago and had a loose fit on one of them though. He could than probably do with this trick as well.

Nevertheless, where does a worn kingpin hole than come from? just from fitting new kingpins once or twice?

Yup!
heating the arm too much to get a worn pin out.
corrosion.
a mushroomed pin from too much hammering.
some of the replacement pins have a very sharp edge that reams out the arm as its drifted in.

Viking
agree but oversized Kingpins...Where?

in some countries there is not a plentifull supply of decent 2nd hand arms

and no a welded arm isnt going to last as long as a good original but where needs must its a quick and easily achieved "in situ" fix.

One of our very sucsessfull racing teams used to drill a 12mm hole right thru the eye and then plug weld the kingpin into the arm.
obviously this was on a pampered racer that never went more than 3hrs without a kingpin grease so bush wear was minimal.

Sean

The oversized king pins are not in stock at the moment but we are expecting them in 2-3 weeks time. 2 pins sizes are available 17,1 and 17,2 mm dia. These pins has been tested and they work very well where standard pins of 17,0 mm fail.
It is not a kit but pin only. You need a reamer adjustable to ream out the bushes and also put the reamer through the arm to make round again. From here it is the same job to fit the oversized pin. When we have stock again, I can let you know.
Someone from the UK told me that a person or company is/was trying to produce some oversized pin but that’s all I know. It is a bloody good idea and to me a proper way of fixing the problem.