Wheels Manufacturing Derailleur Hanger - 27 17x9 and the ratchet wheel is

and the ratchet wheel is generally used on the rear wheel

model 20P-1 fork/frame mount (PM) 74mm caliper post mount 74mm size +20mm color black/stainless

model 40-Series lower S

}SRAM/Truvativ GXP BB86 Stainless Steel Bottom Bracket Road

Wheels Manufacturing Derailleur Hanger - 27 17x9 and the ratchet wheel isWheels Manufacturing Derailleur Hanger 27. Wheels Manufacturing hangers are stiffer than almost any OEM hanger which improves durability and shifting performance. OEM hangers are only produced by a handful of manufacturers mostly in Taiwan and China. As a result you will see many bikes with exactly the same hanger. Bicycle manufacturers may make mid year changes. Please use the hanger photos to select the proper hanger for your application. These