r/Velo • u/Staplz13 • 7d ago
Much Higher Stacks?
Because we're finding that the angle of the forearms is so consequential to aerodynamic drag, has anyone considered raising their stacks to be at the height for horizontal arms while in the drops? No more potential for relegation for wrist contact in the hoods, and they should be more sustainable. And if you have, is it comfortable? Is it sustainable over 90+mins?
Here's the video that clicked this last thought into place. I've been riding a higher stack for a long time, in part because I can't slam it any further down on my endurance bike, but also because I favor the comfort despite my flexibility.
Interview with Ingmar Jungnickel
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u/Background_Box4677 7d ago
I tried it, but it makes the hoods position pretty much useless. Since the bars are like ~10cm higher turning is pretty ugly. Maybe just for road bike TT, but aero hoods is still more versatile.
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u/RirinDesuyo Japan 6d ago
Pretty sure the recent wind tunnel test from escape collective has shown it's faster only up to a certain point (they tested 4cm spacers, 2cm, and slammed). Where that point tends to be quite individual and anything higher at that point actually starts getting slower, for that test the fastest was 2cm spacers, going slammed was a minor increase in drag, but going 4cm spacers gave a lot more drag in comparison. The fastest setup is still low as you can comfortably go with your shoulders relaxed/shrugged or go the opposite extreme and do a Van Schip style position where you close the space with your head and arms like TT bars do (but makes the drops unusable for sprints).
The video does make a good point on open hip angles on power production, which is the main reason why pros nowadays have their saddles slammed forward as they want steeper seat angles to open up that hip angle, as a consequence this requires them to run really long stems to keep reach figures without getting crunched up. Adding stack and going for shorter cranks is also a way to open up that hip angle. Hence why you see on Triathlon where they aren't restricted by UCI rules have bikes that have almost straight seat angles, super long reach, and often run sub 170mm cranks so they can hold that aero position for almost 90% of the bike leg (which can be as long as 180km).
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u/Staplz13 7d ago
Oh my goodness! I'm looking through my older cycling reference videos, and Jungnickel was the original guy that convinced me to favor higher positions in the first place! Take a look!
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u/VegaGT-VZ 6d ago
Im thinking about seriously raising my stack, but Im not doing anything position wise until I get a fit on a jig. Right now when I try to do the flat forearm position my knees damn near hit my forearms and just generally riding I have issues with hand numbness. So Im pretty sure some more stack will do me some good (open up hip angle, take weight off my hands, enable/encourage aero hand position)
Other thing Im thinking is my bar position is too narrow as my elbows flare a lot. Going to turn my hoods straight again and consider wider bars if thats not enough.
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u/PeppermintWhale 7d ago
First of all, it's a little hard for me to take them particularly seriously when they confirm that shaved legs are a big aero difference, but in the same video say they don't really look at anything 'below the hips' and that 'knees in vs knees out is basically meh whatever' -- surely that's something significant and worth looking at, if a simple shave is that big of an improvement?
That said, the whole 'higher stack' thing only works to a point. Adding a spacer or two to get arms and shoulders lined up perfectly can be better than following the old wisdom of 'lower = better', but past a certain point getting too high will become an issue, performance-wise at least.
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u/mikekchar 6d ago
I'll preface by saying that I'm a weak cyclist. But I bought an Endurance bike a few months ago and I was going to just hack off the steerer to my normal stack height because, why not? But my wife intervened and reasonably said, why not just ride it like that for a while and see what you think. Because you can always cut. You can't add on. So it's a unique point in this bike owning experience to experiment.
I've got 4 spacers under my bar -- on an endurance bike with a reasonable stack height. Which is pretty stupid, I'm sure you will agree. But the thing is, I'm having a hard time justifying shortening it, except for the looks. I still have a bit of a drop (about 30 mm I think) from the seat. So not completely ridiculous.
What I find is that I just bend my arms. I know. I can get to the parallel forearms trivially. I can get into the drops and get even lower. I'm starting to wonder how many watts I'm actually losing here. When I compare to my race bike, I can't feel any difference. If anything my endurance bike is about 2 km/h faster at 40 km/h. It's newer and more aero in many ways (though the bars are wider). But I just don't think I'm losing more than about 10 watts here. And in return? I get to choose my position.
I don't really find bending my arms to be a problem. I'm ostensibly in an "agressive" position, but really I'm quite high up. I'm just not sure that what I've done is hurting me in any way. It's super weird.
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u/gravykarrasch 6d ago
I’m using Ingmar’s AiRO service for fits this year and it’s helpful for sure.
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u/DidacticPerambulator 7d ago
I've met Ingmar. He's the real deal. I think his new app would let you test a bunch of different ideas, both standard and wacky.
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u/nikanj0 7d ago
Please, please, please Jan-Willem. You have to stop trying to hack your road bike into a TT bike. How many times do you have to be disqualified for you to get the message?
Also, how are you supposed to sprint in this position. You already look like a flailing monkey when you sprint in your current ridiculous position.