I’m planning to run a new Shimano chain/cassette/rear mech with an 11sp SRAM crank and chainring.

Chainring says SRAM CHAIN ONLY.

Sensible guidance or marketing scaremongering?

The latter probably. Unless the thick/thin design of the official SRAM chainring is different to everyone who copied them, can’t see why there’d be any problem.

However I’d go with a KMC chain anyway. Shimano chains are a pain with their directional stuff and silly joining pins, SRAM chains snap easily, but KMC are rock solid.

That said I only know 9/10sp. Not heard anything bad about KMC 11sp though.

OK thanks. Good logic. Lots of 3rd party rings and chains and allsorts.

I’ve run mixed 9/10sp stuff in the past, but just wary of tighter toleranced 11sp stuff.

Running 11 speed kmc chain with sram ring at the moment…. no problems.

KMC 11speed dont run as well for some reason…. We’ve dropped them now, the SRAM chain is much better. The new sil tec Shimano chains are very good, and adding a quicklink makes them less of a pain, but they are a bit spendy.