Collins busts a 6.52 world lead in Dusseldorf:
http://www.youtube.com/watch?v=MzA3giNRTtE
Like I said, all this guy needs to be amazing in the 100 is a stretched-out top end.
His arm action on the way back is chopped short, which chops his stride a bit short.
GREAT for early-middle race pickup, bad for top-end speed.
Check out the slow-mo around 1:00 into the youtube video--check out how short his contact time is.
Nice. He can do that because he is very light. Even if he were to extend his backswing and therefore his stride, he wouldn't need much contact time to develop sufficient force application to counteract the effect of gravity during his stride, tending to bring down his CG, because he is so light.
6.52 PR at 34? In my experience, there is nothing amiss about doing a 60m PR at 34, given good training and freedom from injury.
The time is within the range of the best clean ever--there is always a bunch of very good guys bunched up in the 6.55-6.60 range, and even more in the 6.60-6.67 range.
What is with Collins' turnover? Look at his arm speed! There is no lag at the extremes of the range of motion. What? Same with his legs. Maybe it's because he's staying within his muscular sweet spot.
That's what happens to all but the best sprinters when they try to stretch out their stride at top speed--they experience a lag. The point at which the product of stretch (joint angle) and force production is a maximum is where you want to be. To get faster, you have to increase this product by increasing one or both of the 2 variables.
If you increase joint angle too far, you get a proportionally greater diminution in force production potential and a consequent diminution in overall limb speed.
It's a tough balancing act, to not over-stride, as we all know.
Judging by Collins' joint angles and turnover, I would say that he has some room to improve at the top by stretching it out a bit, but what do I know--he's better than I ever was.
All I know is that if I were his coach, I would be working on drills and exercises that particularly work on force production at extreme joint angles, beyond those experienced in running, to enlarge his muscular sweet spot.
All the rest of the pieces of the puzzle are there. His blocks aren't great, but they're not bad either.
A final note to all the rose-colored glasses wearers among you, who think that I believe everybody to be doping: I can, and do, believe that a world-leader in a short sprint can be clean, when not all top runners are competing. I choose to believe that Collins is that guy.
Although there is a little voice starting up...