Hoping someone has an answer to this:

Been using enkei RPF1's in 16x7 et43 from Tire Rack for my MINI. I've been using the plastic centering rings that Tire Rack sent with them. After about a month or two, the plastic rings have gotten extremely difficult to put on and off the hub. I assumed the plastic rings had deformed from the heat etc from autocrossing, so Tire Rack sent me aluminum centering rings.

However, the aluminum centering rings also do not fit the hub - they get stuck at about the same spot the plastic centering rings do. I can still squeeze on the plastic rings since they have some flex, but not the aluminum ones. So, I lightly sanded the hub itself, and the inside of the centering rings - still won't go on all the way.

Is it possible that the hub itself has deformed? The OEM wheel still fits perfectly though, so is it possible the plastic rings deformed AND Tire Rack sent me the wrong size centering ring? Aluminum ring looks the same as the plastic one which fit perfectly in the very beginning.

 

This exact same thing happened on my MINI when I still had it. I also had Enkei RPF1 wheels, although in 17" size. Same hub though.

What I found was that the plastic rings would eventually get so tight that they cracked. Funny you mention it but I also ordered aluminum rings. They also were an interference fit! I completely doubt the hub is deforming. It's just a little different specification than what those spacers are designed for. All four of my hubs were this way on my car.

I eventually just went back to the cracked plastic rings. The wheel lug torque/static friction is what holds the wheel on the hub anyway, not the hub itself. The physics don't lie. On my front hubs I eventually had a big brake kit with 10mm spacers which ended up giving me zero hub at all to sit my wheels on. Each track day I always made sure the tightening torque was correct on my lugs before each run and never had any problem in four years. It's if you forget to check your lugs that you get into some real doo doo

 

very interesting - i can't imagine the hub is deforming either - so you think the plastic rings deformed and the aluminum rings just aren't the right spec?

what i may do for now is dremel down the inside of the plastic rings and see how that works

 

I'm not sure if there is an SAE standard for hubs but yes, the way that those hubs are machined must be different than what those rings are designed for. It's not off by much though.

 

yeah it's very close - the plastic rings actually fit perfectly when I first got them, then they started not to fit. the aluminum rings get tight at the same spot the plastic ones now do, and they actually don't fit inside the wheel perfectly either. i may swap to studs soon which will make it easier, still kind of annoying though.