Some work on the bike this weekend.
We had some rattle on the high 50t chainring with a 39t mid. Moving to a larger 42t mid I finally noticed the rattle was derailleur clearance with the mid. We are using the high Shimano mount. With our 2015 Calfee I had issues with interference with the water bottle mount. I shaved the mount to get enough clearance.
The current set-up is a 50-42-28 + 11-30, and 11-32 when we the extra bail out gear. On the 28 there is some rattle on the FD rivet. This is a large range, so we will see how it works.
I am coming around to the twocicle's point of view (this has taken a few years). We do use the 50-11 downhill (we have no sprint) and used/enjoyed have 52-11 when we had it. But 48-11 is likely enough.
I picked the 42 to try and be on our flat/rolling range w/o a big chainring change. We will see how that works out in practice, and of course will be tinkering.
jeffs
jeffs