informant--
"possible for certain athletes to run 9.6 clean"
Exactly which athletes?
Let's exclude the Big 3 for now...Based on the best available evidence, the only athlete possibly capable of having done that would have been Donovan Bailey, based on his 9.84 in 1996. Only IF he had run the same race with a start equal to the field, and IF he had had a maximum allowable wind, could he perhaps have gotten down to 9.6x
Bailey's 9.84 (+0.7) in 1996 was a 9.88 corrected, which would have been a 9.78 with the max +2.0 wind. Subtract another 0.10 to give him a start equal to that of most of the field, and he would be down to 9.68...only just barely into the 9.6x's, IF he had extreme luck of 2.0 wind, and IF he ran his best possible race as he did in Atlanta, and IF he had his best possible start, which would have had him even with most of the field.
Those are big IF's, and it is readily apparent that Bailey never ran when all these factors were present, as he never did go 9.6x
The other 3 possibles are Surin 9.84 (+0.2), Fredericks 9.86 (-0.4), and Boldon 9.86 (-0.4), which all correct to 9.85, which would all be around 9.75 with the max allowable +2.0 wind.
The difference between these runs and Bailey's is that Surin in Seville, Fredericks in Lausanne, and Boldon in Athens all had excellent runs, with excellent starts--i.e. essentially the best that could be hoped for by those athletes. Unlike Bailey, there is no glaring weakness in their start or elsewhere that would get them the additional 0.6 required to reach 9.69
Boldon's race was essentially flawless:
http://www.youtube.com/watch?v=QO8ciTUEztQ&playnext=1&list=PL8B919936B4E65148
Surin's race was essentially flawless, except for perhaps a slight bit of tightening from 80-100m:
http://www.youtube.com/watch?v=tT6J0nEIEYs
Fredericks' race was essentially flawless--can't find a video, but I remember it.
None of those guys, based on the evidence, could have gotten 9.6x, even running their perfect race under perfect conditions.
Nobody else is even in the running.
The only other probably clean athlete even in the discussion is Carl Lewis. His 9.86 (+1.2) in Tokyo corrects to a 9.92, which would have been a 9.83 with a max +2.0 wind. Like Bailey in Atlanta, Lewis in Tokyo had a crappy start. Although he was never a great starter, he certainly showed throughout his career that he could start at least as well as the general field. Like Bailey in Atlanta, Lewis probably gave up 0.10 at the start, but even if he started with the field, that would only get him to 9.73, running essentially his perfect race under perfect conditions with his best start possible.
Excellent, but not 9.6x territory.
Johnson, Gatlin, Montgomery, and IMHO Greene are out of the discussion, as you referred to running 9.6x "clean".
That leaves the Big 3.
You say you know elite sprinters that have run clean in the 9.8's, and who were not at max. The only 9.8x guys I can think of, other than the Big 3, who were not at their max are, as I mentioned, Bailey and Lewis, who did not have their best possible starts yet still ran 9.8x--and of these 2, only Bailey could possibly have run 9.6x
So, because you believe that "certain athletes" (plural) could run 9.6x clean, and Bailey is only a single athlete, that must mean that you believe that somebody other than him is capable of a clean 9.6x.
Based again on the evidence, nobody other than one of the Big 3 is in the running.
Which of the Big 3 do you think could run a clean 9.6x, and why?
Bolt gives no indication that he can do it. His times of this year don't correct to 9.6x, and he has never demonstrated a significantly better start during the years when he was not under suspicion for using.
That leaves Gay and Powell.
I'm down with that. I suspect that Gay's 9.6x and low 9.7x were not done cleanly, but I also suspect that he could achieve those times cleanly, he has a beautiful running mechanic, and I don't think there's any particularly necessary reason for his inferior start.
And Powell has a beautiful start and acceleration mechanic, although he could use some tweaking at full speed--but he can run well at full speed, as evidenced by his 37.10 relay leg. He has run so many meets, over so long a time period, been tested so many times, been overshadowed by a new golden boy, etc., that one would think that he would have been caught at some point had he been using. But the same could be said for Greene, although with Greene there is other evidence of use that is absent in Powell's case.
So, for you, is there anybody other than Bailey, Powell, or Gay that is possibly capable of running 9.6x clean?
And your statement that "There is amongst the elite coaching community a very real development in technique in sprinting that has allowed athletes to run faster." is misleading.
More accurately, the elite sprinting coaching community has begun to successfully incorporate elements of superior technique demonstrated by some athletes in the past, into the training regimens and race technique of current athletes.
What that means is that a particular athlete who would not naturally run with that technique runs faster than they otherwise would.
It does NOT mean that there is a general improvement in the field, because some athletes run naturally with that technique and do not improve based upon changes to their already-excellent technique.
The best sprinters of the past used elements of this newly-recognized suite of techniques, and the very best of the past, in their very best races, used essentially ALL elements of this newly-recognized, but intrinsically OLD, suite of techniques.
So-called "new" techniques allow individual sprinters deficient in technique to run faster, but do not allow elite sprinters in general, as a group, to run faster.