I figured this would be the case. ECS sells some attractive Alzor wheels that are clones of the JCW cup spoke.
I need some extra wheels so I can have snow tires for the winter and summer tires for the nice weather, so this seems like a great option - instead of $450/wheel, these are $450/set.
But they definitely don't have the clearance of the genuine JCW wheels. I received them yesterday, and here's where they fall with the spoke touching the face of the caliper:






So I need to measure for spacers -first I just slid the wheel onto the two wheel hangers. Gravity of course makes the wheel tilt on the hangers so the distance to the hub isn't even, so I finger-threaded one lug bolt in down lower until the wheel was held vertical. I really just did an eyeball reference for an even gap top to bottom and around the sides.
Then I made a pencil mark on a piece of tape on the end of a small ruler - could have been a piece of a stir stick, just something that fits inside the wheel. I just held the edge of the tape against the hub and made a mark where the wheel was. I double and triple checked it, because perspective angles can really change where the mark appears to be.
Then, outside the wheel, I measured the distance from the edge to the pencil mark:





Looks like about 7 or 8 mm to me, so I would think a 10mm spacer would be sufficient. Does that seem correct?

I have never had or measured for spacers before.

 

Also, not that it matters much - but the factory wheels that came on this car are 100% black, they look cool enough, but there's some minor curb damage that someone clearly painted black.
I prefer the look of the cup spoke, so I think I'm going to have the tire shop transfer my summer tires to these faux cup spoke wheels for summer use, and will put the snow tires on my factory wheels.

So with luck, in the summer these won't poke out, hopefully they are simply a little more flush than the factory wheels?
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We have 8mm and 10mm, 10 will give you more clearance. Thanks for posting this info up. Put one on and spin the wheel. You can also tape up the caliper with blue painted tape. That what most MINI people do on testing with JCW brakes.

 

Tape is a good idea to test the spacers - my buddy with the F56 has some 10mm spacers, I'm going to try those out to see if that's good for rotor clearance. I'll bring some tape out to be safe, good idea.
Maybe I can even put a block of wood under the wheel and lower the car down to see where the face of the rim falls with the suspension at rest.
If I'm good behind the wheel spokes, and good with the wheels not poking out - then I'm good!

 

Here is my suggestion...

Remove the caliper, and tie it up out of the way. Mount the OEM wheel, and measure the distance from the back of the wheel to the rotor face at two points - the rotor edge, and at the rotor hub. Then, mount up the aftermarket wheel, and measure the distances again. Subtract the difference between the two, and now you have your spacer requirement. I did this when I mounted up my GP2 caliper conversion.

 

That is a good idea!
I have the easy way out with a 10mm set of spacers to try out (I think this weekend) but I like that idea. Pretty easy.

 

Following up on this thread….

What size spacers did you end up using for clearance?