Very similar here. I had several contributing factors; tuning, suspension and weight distribution. I had started a thread on working on the suspension component of the sixty foot times - here.I had so many factors this year between removing the bar, turning up my tune, and bumping my stall that it is really hard to say how much of an effect that had on my 60s.
I actually have barely scratched the surface of the depth of this topic. I hope to work more earnestly on this starting this winter following the holidays.