The answer as always it depends. In general raising the extensions and pads with an Aero spacer or mono spacer (tririg, cervelo, trek etc) is more Aero than using the steerer tube for extra height.
The main thing is being adjustable so you can dial in your body's comfort and aero. That's why so many people are talking about tririg.
When you need to shell out £1000 on bars you need to know which is best for you.

Of those two, the PRO Missile Evo, no question. Newer doesn't necessarily mean better/faster though. The 3T Ventus II is still one of the fastest, and even the open-mold stuff from the likes of Planet X are only a few watts behind much more expensive choices.

General rule of thumb is 60mm above the base bar for good separation.

---

---

Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

Interesting rule of thumb as I haven't found this at all.

I've always kind of wondered about this as well since I've always ran Felt Devox bars with the pads right on top of the bars. My position and setup is fast enough that I'm very hesitant to make any significant changes (which is why I'm upgrading my 8 year old Felt B14 instead of a new bike). If I had to guess, I would think you either want the pads right on top of the bars as I have them, or separated by a minimum gap (60mm was mentioned above), and not in between.

---

-Bryan Journey
Travel Blog | Training Blog | Facebook Page

Care to expand on this? This was pushed out by Felt when they were doing a ton of testing at LSWT.

What have you found and how have you tested it?

---

---

Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

I don't like making changes just for the sake of it (i.e. the internet told me too), but rather there should be a purpose behind it should be properly tested. I'm slammed on my Tulas and very aero as a result, so you're probably fine (those bars are quicker than most, Bussell used them on his P2 when he won his second Nat 10 TT a few years ago).

Thanks for those names, the Planet X bars are exactly what I was talking about and they seem to be the style the English Track team were using.
The pads appear to be 3" above the handle bar. Better price than the others as well.

I've found that the frame makes a difference, but ultimately rider position trumps all. Testing-wise, I've done many hours with AeroCoach. When I had to replace my Plasma 3 TT (with 30mm spacers), I specifically chose a larger P5 so I could run my pads directly on the basebars (yes I have a lower CdA now, obviously not entirely due to frame/bar selection, but by how much was surprising considering how much time I'd spent getting dialled on the Plasma).

https://www.instagram.com/p/BZiwcNml9MC/

I don't think you and I are talking about the same thing? I don't disagree, nor do I think anyone disagree, with what you said about frame/rider. I was referring to bar/ rider interaction. Getting 60mm of risers generally allows enough air to move through the space and can be faster in some instances. Otherwise it is recommended, like you found to have the pads as close to the bar as possible.

---

---

Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

So you're talking all (>60mm) or nothing? When I was testing my Plasma 3, my CdA went way up when I removed the spacers (I'll have to refer back to the data as this was years ago, but it was dropping either 10 or 20mm onto the bars).

That's what was found provided the position stayed the same. As such I've not really tested it much as there is way more low hanging fruit.

---

---

Heath Dotson
HD Coaching:Website |Twitter: 140 Characters or Less|Facebook:Follow us on Facebook

I realize it has a lot to do with frame size, as I ride a slightly small frame for my height (P3c bought cheap) I have the opportunity to drop the handlebars way lower and keep the bars up. Right now it all sits high and I believe clutters up the place. As I came to this from swimming I'm already pretty big to the wind.

Also this is in a totally unscientific belief that it may be faster as the people who actually spend money on testing seem to set up track and TT bikes like that.
Was hoping that someone here was an expert. :0)

The faster aerobar is the one that will give you your best position on the bike. A lot to me aren't adjustable enough for what is best for you so I would base choosing an aerobar based on adjust ability and fit rather than what tests lowest cda in a tunnel with no rider.

You might be right ( there's a song there) but it's -15 tonight and I'm trying to think summer.
So this is silly season where I drool over stuff that will make me 1 minute faster in an IM

Not forgetting that in my last IM I spent 38 minutes in total transition time

Haha fair enough. Personally I would probably buy the Tririg Alfa One as it ticks all boxes including ease of adjust ability but I run and love the Pro Missile. It is very time consuming to adjust position but it is the cleanest set up going around.

But assuming you know what your best position is, and can dial it in on the frame/bar combo, is it better to have a tall frame and low bar stack, or a low frame and tall bar stack? I suspect that's the root of the OP question here.

Well aerodynamically you are better a short frame, low base bar and a tall stack height. Then you have to find the aerobar that accommodates that.

True? I thought Slowman was on the other side of the fence...

I think he likes larger frames for fit and stability.

Can you show or say any more about that testing?

60mm is quite a lot if that is the spacer stack.

Except I'm not. And I know many people with very low CdAs that aren't either. I don't know where that statement has come from, and I'd argue that guidance akin to fitting a penny farthing isn't where anyone should concentrate their efforts.

To add another point on larger frame less pad spacers: during his time with Felt, Dave Koesel seemed to always recommend the largest frame one could fit on. To me this makes sense, not that aero has to, but the larger and properly shaped bits of the frame seem like they would handle airflow better than a set of spacers.

I'd love to test this, but it seems a little impracticable. Also, reach becomes an issue when adjusting for frame size; especially, if one is trying to make up for 60cm of spacers. However, a flexible bar would allow one to accommodate this issue. Anyone want to loan me their 58 Da?

---

My YouTubes

That's interesting I currently ride a Plasma 3 small, with my missile evo extensions at their longest position. Similar to your self to ensure 3cm compliance I went out and brought a 54 P5 to get a bit of extra reach the got a tririg one for it. Because i have invested in 2 Newport sessions in the Plasma I have stuck with it though it is a bit battle scared. As a 172cm short arse I expect really a 51 P5 would be the frame I should be on, but have wondered if stack height via a larger frame is more aero than stack height via an aerobar.

I am hoping I can at least replicate my Plasma fit on the 54 so I can use it for training as the Plasma is set up as 1x which isn't always helpful for longer training rides in the TT position. Otherwise I will have to sell it and try and find a 51 P5 or P3.