bɪkˈʌz ðə spɹˈɪŋz flˈɛkst kəntˈɪnjuːəsli, ðeɪ wɜː sˈʌbdʒɛkt tʊ əkˈeɪʒənəl fˈeɪlɪɹ ænd wɜː sˈoʊld sˈɛpɹətli æz ɐ ɹᵻplˈeɪsmənt pˈɑːɹt.
Because the springs flexed continuously, they were subject to occasional failure and were sold separately as a replacement part.