Anyone know whether the current generation Shimano road cranksets are backwards compatible with the earlier 10 speed stuff (ultegra 6600, to be precise).
Their fact sheets seem to say not, but unless they’ve changed chain line or spacing between chainrings I can’t see why this would be an issue. Anyone able to help?

Front mechs/LH shifters aren’t, otherwise they are.

Think pretty much all cranksets are backwards compatible, I’ve got 9 and 10 speed cranks running interchangeably with 9 and 10 speed shifters.

ok, thanks. So the spacing between rings is unchanged then, just the cable pull ratio has changed?

And what’s the story with the directional chains? There’s no issues running ordinary 10 speed chains?