The aluminum has mechanical properties enable to a better finishing in welded region. However, it fails eventually when a dynamic load is applied. This study estimated the damage by multiaxial fatigue present in welded joints of bicycle frames, the methodologies of analysis are based on Findley's and Dang Van's Methods. Seven experiments were performed on two pipes with welded joints. These pipes were choosen according to Bike S/A data, numerical simulations in bicycle frame and previous analysis of specialized literature. Therefore, lifespan result of frame, in function the distance, is $3\times 10^4$ km - $5.5\times 10^4$ km.