Low hanging aero fruit - handlebars?

Discuss light weight issues concerning road bikes & parts.
RocketRacing
Posts: 934
Joined: Thu May 10, 2018 2:43 am

by RocketRacing

robertbb wrote:
Sat Oct 20, 2018 9:50 pm
bilwit wrote:
Sat Oct 20, 2018 9:04 pm
5W measured with or without a rider? :wink:

BikeRadar did a wind tunnel test with wrapped aero bars that showed only a 1W difference between wrapped and no wrapped.. but the configuration they showed was without a rider altogether which makes me think that the actuals savings is magnitudes less than this number
^^^ Truth.
I disagree.
A8340922-B34F-4508-98C8-248F81006F81.jpeg
I just kind of randomly pulled this from the internet, but look at the air turbulance behind the bars. First, as you both imply, in the big picture, the drag from the bar tops is small potatoes.

However, note that the air turbulance created by the tops of the bar (drag) resolves before it reaches the rider. Thus, the drag is addative to the drag of the rider. So if aero tops save some watt of drag, it should be about the same rider or not.

I suspect if the saving is say 5 watts without rider, than with it should be 4.5 watts or some other close number with a rider.

All armchair logic, but just putting it out there.
Last edited by RocketRacing on Sat Oct 20, 2018 10:37 pm, edited 2 times in total.

by Weenie


spartacus
Posts: 115
Joined: Mon Apr 04, 2011 6:53 pm

by spartacus

Yeah I still can't decide if it's worth it because of the reasons you guys mentioned:

1. Hard to find round shaped drops
2. Probably aren't as stiff as aluminum bars
3. They're very expensive unless you buy random Chinese ones
4. The watt savings are probably real but it's tough to estimate how much of a difference it would really make.

On the other hand... Free watts...

As for taking spacers out, personally I have my bike fit pretty well figured out and my stem is all the way slammed on both of my 56cm frames and they both have ~10cm drop - that probably won't ever change.

RocketRacing
Posts: 934
Joined: Thu May 10, 2018 2:43 am

by RocketRacing

Yeah, the real world decision should be stiffness vs cost/minor aero gains(But for me, i will be honest, looks is a big part of it!)

The aero gains are there, and are real, but they are small in the big picture. Is 5w savings at 30mph worth a wet noodle feel on the sprints, and some fat cash? Depends on the rider but...

Now, just like weight weenism... i think aero (beyond the rider) it is only really worth it if you go “all in.” Just like people who say 100g savings means little... well yup, they are right. 100gx20 adds up. Aero bars alone are probably not worth it, but if you already have the aero wheels and frame, i say go all the way.

wingguy
Posts: 4307
Joined: Thu Mar 08, 2012 11:43 pm

by wingguy

rlpaul wrote:
Sat Oct 20, 2018 6:58 pm
The Castelli clothing that Sky wears, as well as the similar clothing that Movistar wears (don't remember which brand they use), were banned yesterday. Unfair advantage, yadda yadda. Interstingly, Castelli claims they have new UCI legal clothing that's even faster, so... :noidea:
That’s interesting. Cuts out a grey area at least. Funny thing is Castelli already had a smooth fabric suit for the TTT at Le Tour. They said it was faster for TTT speeds, while the dimple suit was still better for ITT speeds.

And while Castelli never really marketed the Bodypaint 4 (you could get measured for one at Vicenza for a couple of €k) Endura have built an entire D2Z road and TT range around their vortex fabric sleeves and legs.

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Lewn777
Posts: 865
Joined: Thu Mar 09, 2017 5:35 am

by Lewn777

What's stopping me is that on days when I'm endurance riding on my own I want clip-on TT bars on my (future) aero bike, obviously I'd remove them for group riding. Clip-on TT bars save as much or more time as deep section wheels, but by adding an aero bar you're making it in most cases impossible to run clip-on TT bars as they need to be mounted on a round bar. So I'd be gaining a tiny amount of watts on group rides but throwing away loads of potential watts when riding alone and that doesn't seem worth it.

bilwit
Posts: 1212
Joined: Sun Apr 03, 2016 5:49 am
Location: Seattle, WA

by bilwit

Lewn777 wrote:
Sun Oct 21, 2018 12:24 am
What's stopping me is that on days when I'm endurance riding on my own I want clip-on TT bars on my (future) aero bike, obviously I'd remove them for group riding. Clip-on TT bars save as much or more time as deep section wheels, but by adding an aero bar you're making it in most cases impossible to run clip-on TT bars as they need to be mounted on a round bar. So I'd be gaining a tiny amount of watts on group rides but throwing away loads of potential watts when riding alone and that doesn't seem worth it.
the ENVE clip ons are designed to mount on the ENVE aero bars.. but all of them are ENVE priced though :lol:
RocketRacing wrote:
Sat Oct 20, 2018 10:35 pm
robertbb wrote:
Sat Oct 20, 2018 9:50 pm
bilwit wrote:
Sat Oct 20, 2018 9:04 pm
5W measured with or without a rider? :wink:

BikeRadar did a wind tunnel test with wrapped aero bars that showed only a 1W difference between wrapped and no wrapped.. but the configuration they showed was without a rider altogether which makes me think that the actuals savings is magnitudes less than this number
^^^ Truth.
I disagree.
A8340922-B34F-4508-98C8-248F81006F81.jpeg

I just kind of randomly pulled this from the internet, but look at the air turbulance behind the bars. First, as you both imply, in the big picture, the drag from the bar tops is small potatoes.

However, note that the air turbulance created by the tops of the bar (drag) resolves before it reaches the rider. Thus, the drag is addative to the drag of the rider. So if aero tops save some watt of drag, it should be about the same rider or not.

I suspect if the saving is say 5 watts without rider, than with it should be 4.5 watts or some other close number with a rider.

All armchair logic, but just putting it out there.
now we just need Hambini to test it and show how none of this is really applicable in transient, real-world scenarios :lol:

RocketRacing
Posts: 934
Joined: Thu May 10, 2018 2:43 am

by RocketRacing

Lewn777 wrote:
Sun Oct 21, 2018 12:24 am
What's stopping me is that on days when I'm endurance riding on my own I want clip-on TT bars on my (future) aero bike, obviously I'd remove them for group riding. Clip-on TT bars save as much or more time as deep section wheels, but by adding an aero bar you're making it in most cases impossible to run clip-on TT bars as they need to be mounted on a round bar. So I'd be gaining a tiny amount of watts on group rides but throwing away loads of potential watts when riding alone and that doesn't seem worth it.
Get a 3t aeronova. Made to accomidate clip on bars.

RocketRacing
Posts: 934
Joined: Thu May 10, 2018 2:43 am

by RocketRacing

bilwit wrote:
Sun Oct 21, 2018 12:49 am

now we just need Hambini to test it and show how none of this is really applicable in transient, real-world scenarios :lol:
No question. But like 100g saved in weight, 1w aero savings makes sense when you start to add up multiple ”inconsequestinal” gains. A climing bike that is 5lbs lighter will make a difference, especially with a lower powered/lighter rider, and as climb distance and grade increase. If a bike was aero optomized and was the same as adding 25w at 30km/hr... or 2 extra km/hr with your current watt output... most would go for it (cost aside).

I like to use the example of my 1984 porsche 911. With a series of “small” adjustments to various parts of the engine (intake, exhaust, etc) i was able to increase power by near 50% from stock. I then swapped an replaced a number of parts for lighter options, or removed what was not needed. Removing the rear seats and belts maybe only saved me 40lbs in. 2750lbs car... but when i was done i had a 2300lbs car. The new power to weight ratio of the car put it lightyears ahead of the stock 911, and at par with a modern 911 S that had 450+ hp.

It all adds up. But removing the rear seats alone would not be worth the effort. Same for just boring out the throddle body 20%. But i was all in. Go big or don’t bother.

But yeah, i thiught about an aero bar for my bike (felt) and opted against, as i went weight weenie, and it is hard to go light and aero. I went light, even if aero was mathmatically faster.

bilwit
Posts: 1212
Joined: Sun Apr 03, 2016 5:49 am
Location: Seattle, WA

by bilwit

RocketRacing wrote:
Sun Oct 21, 2018 1:09 am
But yeah, i thiught about an aero bar for my bike (felt) and opted against, as i went weight weenie, and it is hard to go light and aero. I went light, even if aero was mathmatically faster.
funnily enough, I just put ENVE aero bars on both my bikes--not for aero benefits though, I wrapped them all the way like Kittel/Wiggins/Cummings. They're super comfortable when resting my forearms on it like Cancellara, especially when on the trainer :smartass:

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pdlpsher1
Posts: 2424
Joined: Thu Jul 19, 2012 6:09 pm
Location: CO

by pdlpsher1

I know everyone has an opinion on this topic. But if you are already using a narrow bar, look at the horizontal part of the bar. In the middle of the bar it's round. So the aero benefit doesn't come from the entire length of horizontal part. Only a short part of the bar is tear-drop shaped. I think the benefit is very minimal, much less than a good aero helmet.

Image

parajba
Posts: 613
Joined: Tue Oct 28, 2008 9:00 pm
Location: London, United Kingdom

by parajba

Great topic. I am in a similar position to Spartacus.
Have an S2 (older model from 2010) and was thinking to replace its traditional round bars with the aero handlebar (perhaps the one made by Cervelo for the ‘old’ S5 or the Zipp). I already have a Giro Vanquish and Zipp 303s.

Like Spartacus my next bike will be an all out aero but given the current prices of the top models (S5D, Venge, Aeroad etc) I am thinking of keeping my old S2 a few more years and to replace the handlebar.

Keep the comments coming please...

Guevarca
Posts: 32
Joined: Sun Dec 17, 2017 8:49 am

by Guevarca

I wished that Deda would also use their ´shallow’ shape on either an Aero topped or carbon bar. I know Zero 100 Shallow aren’t crazy heavy but it would be nice to have more options using the traditional shallow hook.

Mep
Posts: 500
Joined: Fri May 28, 2004 4:11 pm

by Mep

RocketRacing wrote:
bilwit wrote:
Sun Oct 21, 2018 12:49 am

now we just need Hambini to test it and show how none of this is really applicable in transient, real-world scenarios Image
No question. But like 100g saved in weight, 1w aero savings makes sense when you start to add up multiple ”inconsequestinal” gains. A climing bike that is 5lbs lighter will make a difference, especially with a lower powered/lighter rider, and as climb distance and grade increase. If a bike was aero optomized and was the same as adding 25w at 30km/hr... or 2 extra km/hr with your current watt output... most would go for it (cost aside).

I like to use the example of my 1984 porsche 911. With a series of “small” adjustments to various parts of the engine (intake, exhaust, etc) i was able to increase power by near 50% from stock. I then swapped an replaced a number of parts for lighter options, or removed what was not needed. Removing the rear seats and belts maybe only saved me 40lbs in. 2750lbs car... but when i was done i had a 2300lbs car. The new power to weight ratio of the car put it lightyears ahead of the stock 911, and at par with a modern 911 S that had 450+ hp.

It all adds up. But removing the rear seats alone would not be worth the effort. Same for just boring out the throddle body 20%. But i was all in. Go big or don’t bother.

But yeah, i thiught about an aero bar for my bike (felt) and opted against, as i went weight weenie, and it is hard to go light and aero. I went light, even if aero was mathmatically faster.
Sir I think we need to see that Porsche of yours

Stueys
Posts: 376
Joined: Sat Nov 22, 2014 1:12 pm

by Stueys

Re aerobars being noodles, my 3t aeronova ltd seems just as stiff as my enve round bar to me. My friend has the aeronova team and says that has some flex, it’s slightly cheaper so maybe a less stiff build? But certainly not all aero bars are noodles...

morganb
Posts: 667
Joined: Wed Mar 15, 2017 5:30 pm

by morganb

parajba wrote:
Sun Oct 21, 2018 6:59 am
Great topic. I am in a similar position to Spartacus.
Have an S2 (older model from 2010) and was thinking to replace its traditional round bars with the aero handlebar (perhaps the one made by Cervelo for the ‘old’ S5 or the Zipp). I already have a Giro Vanquish and Zipp 303s.

Like Spartacus my next bike will be an all out aero but given the current prices of the top models (S5D, Venge, Aeroad etc) I am thinking of keeping my old S2 a few more years and to replace the handlebar.

Keep the comments coming please...
I would do the Zipp over the Cervelo by a wide margin. I found the Cervelo bar to be so flexible that it negatively impacted the handling of the bike, plus you are very limited in computer mount options. I have had three Zipp SL70 Aero now and they are pretty much indistinguishable from a stiff alloy bar for sprinting and have enough clamp space for any computer mount even with a wide faceplate stem.

by Weenie


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