Let me preface this by saying that I KNOW YOU SHOULD NOT CROSS CHAIN, but I have SRAM RED and a 'sweet spot' for me for a lot of climbs around where I live is big ring large cog. Now I used to run this all the time with no problem, but now the chain seems to want to drop from the big ring completely OFF (not just down to the small chainring). I assume that this is being caused by the rear dr being too far in when in this combo causing the angle between the front and back to be too great - when I say too far in I mean the barrell adjuster could be adjusted to slightly move the bottom pulley out. Now before people start going off about cross chaining, SRAM even says one of the advantages of RED is being able to run big big with no rub..I have no rub with front dr in this combination, but almost tore up my rear dr this morning on a climb when the chain dropped off the front rings. Thoughts???? BTW, this is on a 61cm Cervelo RS (larger size would seem to have less of a problem due to longer chainstays REDUCING angle between chain rings and cassette).