Originally Posted by
Barrettscv
Do the math, he is not exceeding the chain wrap capacity.
I'm running a 12-27 cassette & a 50, 39 & 26t Crankset without any slack on the small-small combination. The Big-Big combination does not cause any problems or damage. I reduced the problem with chain drop by keeping tension on the chain while on the granny gear.
Your set-up requires 39T of wrap which is exactly Shimano's maximum recommendation for their triple road derailleurs so adjusting the chain for big-big+1" would give you the same chain length as you have now. If you had 52/42/26 or 53/42/26 chainrings as I do the wrap capacity would be exceeded and your chain would be too short.
I don't know what the OP's crank configuration is but big-big+1" is never a mistake unless you change the cassette for a larger one without adjusting it.