FSA K-Force AGX Loop Extension Handlebar Extension Bars AGX Series Gravel/Touring Use – CarbonFull Speed Ahead K Force AGX Loop Extension HandlebarK FORCE AGX Extension bars. The FSA K Force AGX Loop Extension Handlebar is designed for gravel and adventure riders who need added control and hand position flexibility. Its looped extension offers ergonomic support during long rides and technical descents while the carbon construction keeps weight low and vibration minimal. This bar is ideal for riders pushing boundaries on mixed terrain.