@Fivetones I like the yellow calipers!
I'm currently in the same predicament. Trawling the internet for definitive answers on what fits and what doesn't!!
Today I spent some time taking some measurements of the Big JCW calipers. I intend to send the measurements to a wheel manufacturer to ask if a particular rim I have my eyes on, will clear. I thought the measurements might be useful for this thread.
I found that the caliper surface where the John Cooper Works Logo is, was perfectly perpendicular to the brake disc. Ideal for measuring.
Before anyone asks.... that piece of PSE Timber is plumb straight!!
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