Converting an SRAM Apex 2x10 to 1x10 I want to convert my bike to a 1x drivetrain (and move to a dropbar). It's a Commençal Le Route from 2013, full specs are here: mostly a 2x10 SRAM Apex Groupset (34/48 at the front, 11/32 at the rear).

The parts I'm planning to buy are:


SRAM Apex left brake lever
SRAM Apex 10/11 right lever
Specialite TA One 110mm (in French, sorry, to sum up that chainring is advertised as a perfect fit for a conversion)


Are SRAM Apex parts backward compatible? How do I know if the angle of the chain is going to be fine? Should I just go for a full 1x crankset?

Best
You should be fine with the parts you choose. Just be sure that you get a 10x Shifter as right lever and you are good to go.

You can adjust the chainline to minimize a too great angle. You should check if the chainline is better if the 1x chainring is mounted where currently the bigger chainring is mounted or where the smaller one is mounted. 
Chainline is good if the chain has minimum angle on the 5th/6th sprocket.

You can't mount a too big chainring on the inner position. But you could check how much space is left from the small chainring to your chainstay and buy one accordingly. Depends on how big of a ring you want to buy.

Otherwise you could optimise the chainline according to the sprockets you use most of the time.