Can I assemble a SRAM RED eTap system with no front derailleur to create a 1x drivetrain? Will the system still work?

Yes, but we don’t recommend it. 1x systems require X-Horizon Roller Bearing Clutch equipped rear derailleurs for proper function. SRAM RED eTap is not available in the X-Horizon Roller Bearing Clutch 1x rear derailleur option at this time. SRAM encourages riders to maintain the complete RED eTap system utilizing the front derailleur.