The mechanism that determines the propagation speed of the upstream turbulent front of pipe flow turbulence has been proposed recently in our earlier work. It states that the local flow speed at the most upstream tip of the front, where transition to turbulence takes place, determines the global propagation speed of the front. The key was shown to be determining the radial position of the transition point, which can be approximated by the radial position of low-speed streaks at the front tip. In this paper, we will verify whether or not this mechanism also applies to the downstream front. However, the transition is not through near wall streaks, but takes place near the pipe center at the downstream front tip. Through an energy budget analysis in the front region, we managed to determine the position of the transition point, and our results suggest that the mechanism indeed also applies to the downstream front.