Looking for opinions on the following position pics(static). Pay no attention to the blubber, I am merely trying to decide which height or range between heights one might think might achieve the lowest drag. I don’t have any idea if going lower is better or not, but currently do not have the option.
I adjusted seat height to mimic the drop of a 48/51/54 cm cervelo with aduro bars as I set them up in the absolute lowest configuration for me that could be achieved on these 3 sizes. never mind the aduro can not be had without a p5 purchase.
based on above, the height of my back relative to the pic in background is irrelevant, ie not higher on the 48 just looks that way due to seat being jacked up 37mm. camera position and angle are constant between pics and attempted to sit in same place on saddle(ie where I ride). yes I can see up the road.
if I change frame sizes, i’d like the option to go lower, but no need to go too small if it seems like it might be a bad idea. yeah, very subjective and me dependent
little more info, this also comes into play in consideration of switching aerobars. ie the aduro is ~60mm minimum cockpit stack, while something like the vuka stealth is 90mm(per fit calculator on zipp’s site)(cockpit stack =frame stack to armrests)
so to get same drop with the zipp as the aduro, I would need to go to the 48 from the 54. if I want to go lower…650(not wanting to go there)
I’d say all are pretty much even as it stands, whichever you can produce the most sustainable power in. If you can get your lower back a little flatter slightly rotating hips forward, C would be better.
I may try a prologue to see about rotation and ability to go longer on reach if I get nose at 5cm back, but even in past with split nose, never rotated much more than you see now
field testing is in future, but need to decide where the starting point will be
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Of those positions, “A” would be my choice as your helmet and upper back are essentially horizontal.
In the other positions, you are not necessarily getting lower, you’re just moving which portion of your body is the high point.
I’ve noticed that if your mid back is the high point and you slope down again to your shoulders and head that the position is significantly harder to maintain.
With all due respect, you cannot look at this in isolation. You look quite closed at the hip, I’d like to know your hip ROM. Things like “Flub” play into sustainability as well. etc etc.
It is near impossible to determine the best position without actually having your hands on someone.
flub is being worked on now(after 2 years of pretending I would work on it)instead of putting of until spring when i never actually reduce intake due to workload. hopefully it will take this time( I made cookie bars for kids last night and had none so far, did not even think about having any)
I was/am of belief that it is torso that needs to be parallel and not top of back. if/when I relax on occasion in a TT or need to be heads up due to large number of obstacles(other folks), pos A starts to look a lot more like a triathlete doing an IM
really don’t think i am closed up at hip, as there is no power difference in A vs riding a road bike. yes, I would like a 160 quarq vs my 165, but seems 162.5 is as low as one can go currently
I haven’t tried measuring from top of saddle to top of back in the 3 pics.
also, I forgot, I might want to lower saddle a bit more but have stopped that process as drop can’t lower any more currently
I actually found that raising my saddle (this was in my first trip to the tunnel) and increasing the drop (effectively) to achieve a more “normal” leg extension angle increased my overall drag by maybe 30-40g.
not looking to raise saddle, looking to maybe drop it some. this is all just to look at what might happen with increasing drop and pics are full shrug, just not shrug and back drop(requires more focus as I fall out easily if mind drifts)
I estimate C to be 15-20mm lower on highest back point in these static pics(even though it looks higher based on picture in background) have to compare tape mark on seatpost which is 37mm vertical from insertion point
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It’s very hard to tell without measuring drag, but you are already quite low. We’ve played around in the wind tunnel with Foam Dave’s back angle, and there is a low torso angle below which drag increases. You’re already close to that, and your lower positions “look” to be below that area.
just looks that way due to seat being jacked up 37mm. camera position and angle are constant between pics and attempted to sit in same place on saddle(ie where I ride). yes I can see up the road.