Just a quick anecdote about some position woes and finally fixing things:
I have a shoulder that has been bugging me in the aero position. Well, I kept going wider and wider with my arm position to try and get more comfortable. I recently flipped the arm pads in til my forearms were almost touching. I've been on a few rides in the new position and it's pain free.
I guess I'm posting for three reasons:
1. The forums been kind of dead lately
2. I had a long day of studying
3. Just to encourage people to find what works for them.
I glad to hear that your new fit is good. I have heard rumors that its not how low you get, but more how narrow you get. I have the pads on my easton attack all the way in. It seems to work pretty well for the time being. I am going to a try a different setup as soon as I can afford to. The only downside is that it is kinda hard see the meter display.
I have heard rumors that its not how low you get, but more how narrow you get.
Unfortunately you can't rely on such generalizations. Definitely there can be deminishing returns going lower and lower where it really doesn't reduce your CdA any further but does impact power generation. But with the elbow position wide or narrow is purely based on the individuals physiology, which only testing (field testing Chung style with a power meter) or a Wind tunnel can answer.
I had the good fortune to get into our local Windtunnel last year and it was here watching others also getting tested I saw first hand with what worked for one person didn't the next. It also showed that even subtle changes of hand positioning on the extensions (at the end vs part way back I use climbing) or head postioning can impact Cda readings...
In the past I worked with a very accomplished fitter who had put me very narrow up front(he brought me up from 15cm of drop to 13.5). He said my knees were very far in at the top of my stroke, so all things considered we were probably best with my arms narrow. He said if my knees had been farther out he probably would have put my arms wider so that they would be "behind" my arms at the top of my pedal stroke.
John Cobb also goes with the arms in front of knees rule, but tends to err a bit wider.
In all honesty my arm cup placement had a lot more to do with comfort but it's never bad to think about these things.
I think depending on which event you are focussing on and your physiology does play a part in deciding how low to go...
From 2005 I had focussed on Duathlons and now over the last 18 months I've only been racing on the road and velodrome. In doing so my upper body has started to morph towards a roadies build, so the combination of reduced upper body mass, going lower and turtling has given my major reductions in my CdA. Noting also I now don't need to concern myself with running off the bike either means I can force myself to ride a more extreme position.
On the other hand, at the same day at the wind tunnel was a local triathlete. With his swimmers shoulder, no lowering of his positon had any impact in reducing his CdA. In fact the only way which helped him was an extreme Flandis position which as he isn't restricted by UCI rules like I am is able to use. So in the end he moved the bars back up after trying them lower, producing more power and with a more comfortable position run better after the bike.
Comfort plays an even bigger part in IM too. Take a look at footage of any IM - the number of riders in the last third of an IM bike leg sitting up! It's far better overall to compromise the drop a little and ride the whole ride in the aerobars.
The triathlete I referred to above did have good success field testing with a power meter at the local velodrome on windless mornings to test various position options, so this can be tested outside the wind tunnel. The Chung spreadsheet from the Google wattage forum, a powermeter and some time spent testing can produce reasonably reliable figures.
The important thing if changing positions is to not discount it immediately as it will take time to adapt. Now in the (your Northern hemisphere) offseason is a great time to look at trying different things so any adaption required can take place.