Complex on a ten-speed which I've acquired parts that
I find in the garbage, a frame then put tires on it
Em built his own ten-speed bicycle.
This line could be a metaphor to his music which was built from his garbage past. Eminem built his music from acquiring parts from his environment.
Also, notice the reference to the Complex magazine, on which Em was on the cover of prior to the album’s release.
To help improve the meaning of these lyrics, visit “Legacy” by Eminem Lyrics and leave a comment on the lyrics box