You probably don't have to change the chainset at all. An 11-speed chain and front mech will run fine with a 10-speed chainset.
A good article by Lennard Zinn who is the last word on mixing and matching drivetrain.
10 / 11 speed drivetrain compatibility
I was really interested in your recent Tech FAQ columns where you mention compatibility between various 10- and 11-speed systems. I would like to make the move to 11-speed in the most efficient manner, cost-wise and in terms of using components I already have.
In a recent column you wrote that one can use the old SRAM Red 10-speed rear derailleur in an 11-speed set-up, as long as it is matched with 11-speed shifters. That makes sense, as the derailleur lateral movement is determined by the cable pull per shift and ratchet mechanism in the shifters, not by the derailleur. I wonder if an older 10-speed generation front derailleur will be compatible with the current generation SRAM Red left shifter (i.e., is the cable pull and leverage in the front derailleur the same between the current and earlier 10-speed groups)?
I do hope the answer is yes, as I have sitting in the basement NIB SRAM Red derailleurs (10-speed), that I bought and intended to use in a build, but time and work demands did not allow at the time.
Actually, this statement you made is incorrect: “the derailleur lateral movement is determined by the cable pull per shift and ratchet mechanism in the shifters, not by the derailleur.”
Rather, the lateral movement is most definitely a function of the design of both the derailleur and the shifter. The rear derailleur’s shift-activation ratio—the amount of lateral movement of the rear derailleur divided by the amount of cable pull to generate that amount of lateral movement (i.e., the number of millimeters of lateral displacement of the rear derailleur per millimeter of cable pull)—is built into the derailleur. It is akin to the leverage ratio in a rear suspension system (i.e., the magnitude of rear wheel vertical travel per unit of rear shock travel).
The design of the shifter determines how much cable it pulls with each click. If you multiply the derailleur’s shift-activation ratio by the amount of cable pull per click of the lever, the product will be the distance the derailleur moves laterally with each click. In order for the rear derailleur to shift properly on a given cassette, that resulting product must be equal to the lateral spacing between the centers of adjacent cogs in the cassette (the “cog pitch”).
You interpreted correctly that a SRAM 10-speed rear derailleur (road or mountain) paired with a SRAM road 11-speed shifter will shift properly with an 11-speed chain and cassette.
As for the front derailleur, a SRAM 10-speed road front derailleur will work acceptably with a SRAM 11-speed shift lever, but a front derailleur is perhaps the least expensive part of the drivetrain, and SRAM’s 11-speed Yaw front derailleur is a significant improvement over its 10-speed predecessor. Since your SRAM Red 10-speed road front derailleur is new in the box, you might consider selling it and getting the Yaw FD.
Read more at http://velonews.competitor.com/2015/03/bikes-and-tech/technical-faq/technical-faq-10-11-speed-drivetrain-component-compatibility_362722#Lr6GsYmPACvo8CY7.99