Derailleur Hanger For GT Commencal Bicycle Frame Rear Direct Mount Dropout D352 Review. This unique and innovative Derailleur Hanger ruggedly mounts your bicycle’s derailleur directly to the frame for quick and easy access. It provides a secure connection for durable and reliable cycling. The derailleur hanger is simple to use and can be attached to your frame using an 1913-inch or newer thread. This Version 3.0Derailleur Hanger is made with a heavy duty 316 stainless steel construction.