*Tour Aero Bike Test 2019*

Discuss light weight issues concerning road bikes & parts.
robeambro
Posts: 612
Joined: Sat Jul 07, 2018 6:21 pm

by robeambro

aeroisnteverything wrote:
Wed Jan 09, 2019 2:06 pm
@marin:

Ummm, so the wheels really drive this game, don't they? Followed, it seems by the "right" cockpit. And it may well be the case that there is a specific wheel solution for a given frame that will make it better, that these wheels will be different than those that are the best for another frame, and quite possibly not the wheels that the manufacturer sells with the bike.

All pretty confusing for the buyer no? My lessons here are that, if you want a fast bike:
- Buy one of them aero frames. Doesn't really matter which one. You'll ruin it with a couple of water bottles anyway. So probably pick the one you like the looks of. If you care about weight, maybe pick a lighter option so you can still show your goods on this forum without blushing.
- Splurge on a good set of wheels. Can't tell you which ones, because different tests give different results. May as well get some chinese ones at around 6 cm rim depth.
- Pick an aero bar. Fully integrated is good, but perhaps not crucial, other than for aesthetics.

Guessing whether your specific combo is going to be faster or slower than some other hypothetical alternative is a bit of a fool's errand.
I would add two things, if one wants to really buy speed:
-make sure not to use too big tires - many articles seem to point out that you may be forgoing most if not all the aero benefits of wheels if the tires are much wider than the rim.
- use latex tubes and tires that have low rolling resistance in testing (ok not necessarily race tires. I am too lazy to fetch figures, but pretty confident that a guy on a Tarmac w/ deep wheels and aero cockpit and good tires/ latex tubes would probably be faster than a guy on a Venge w/ same everything but Gatorskins and butyl tubes.

by Weenie


hambini
Posts: 493
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Location: Cologne, Germany

by hambini

I would agree with Robeambro.

The only things I would add are as follows

-There is a general concensus that fitting a wider wheel rim is faster. This is totally not true, people are fitting wider rims to cope with wider tyres. If you want to go fast, then a narrow rim and narrow tyre combination are always faster. The exception is if you are travelling at modest speeds when the rolling friction of the tyre is more dominant. Additionally if you are fitting shallow rims, you should aim for a narrow tyre otherwise the drag penalty is twofold.

-Ideally you want to aim for a tyre to rim combination that is almost size for size. Having one bigger or smaller than the other generally penalizes you. If permitted, Mavic wheels with the clipin sidestrips and their own tyres are the outright fastest.

Hambini
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ichobi
Posts: 952
Joined: Thu Jan 19, 2012 11:30 pm

by ichobi

I also came to the same conclusion. I aero pimped my tarmac sl6 with fully integrated aero bars, deep wheels, as well as using latex tube, fast rolling tires, and using light oil in all bearings. It feels super fast and while it might not compete watt for watt in absolute term with the pure aero bike I get a solid ride quality at 6.4kg (with srm rotor 3d+ crank). I felt I lose very little in terms of aerodynamic advantage.

One should also note that there isn't many all round bike that have prominent aero design. The ones I am sure of is the Tarmac SL6, Canyon Ultimate, Cervelo R5 and Scott Addict. A pure climber bike with massive down tube like the Emonda might not performs as well or give you that aerobike effortlessness at maintaining speed 'feeling'.

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kgt
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Location: Athens, Greece

by kgt

At last, a thread about aero in which common sense prevails.

spud
Posts: 804
Joined: Sat Feb 07, 2009 5:52 am

by spud

hambini wrote:
Wed Jan 09, 2019 3:33 pm
I would agree with Robeambro.

The only things I would add are as follows

-There is a general concensus that fitting a wider wheel rim is faster. This is totally not true, people are fitting wider rims to cope with wider tyres. If you want to go fast, then a narrow rim and narrow tyre combination are always faster. The exception is if you are travelling at modest speeds when the rolling friction of the tyre is more dominant. Additionally if you are fitting shallow rims, you should aim for a narrow tyre otherwise the drag penalty is twofold.

-Ideally you want to aim for a tyre to rim combination that is almost size for size. Having one bigger or smaller than the other generally penalizes you. If permitted, Mavic wheels with the clipin sidestrips and their own tyres are the outright fastest.

Hambini
This seems emminenly sensible. Quick question, if possible to answer - when comparing skinny vs fat, say 23 mm section tire vs 28 section tire, is there a typical speed where aero (assuming both are respectively optimized w/ a 50mm deep rim, for instance) delta overcomes rolling resistance delta?

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C36
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Joined: Fri Mar 03, 2017 3:24 am

by C36

hambini wrote:
+2

This is sound guidance

The breakdown of drag that I recorded with multiple riders in a wind tunnel in both steady state and transient condition si below. It's almost irrespective of speed.

The transient has more effect on the slender wheels. On the rider body which is a bluff body, it's the dominant parameter

Image
Hambini,
Should we expect the same “surprises” measuring an aero frame in transient flow test as we had with the wheels? Could you guess if the different with a classic frame (supersix, tarmac...) would be bigger or smaller than suggested in Tour tests?

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AJS914
Posts: 3479
Joined: Tue Jan 28, 2014 6:52 pm

by AJS914

FWIW, the new Tarmac isn't what I'd call a "classic" frame. It has many of the same aero features of the Venge minus the hidden cables.

Of the 10% aero frame drag, I wonder what percentage is accounted for by an aero cockpit.

I just installed 50mm wheels on my C59. I know the frame is shaped like a brick and about as non-aero as can be but the wheels make a good bit of difference. I got two Strava KOMs in the last month. I've been toying with the idea or buying a used Madone 9 or installing an aero road bar on my C59 and calling it a day. Still, I'm not sure 3-5 watts is worth the $400-500 cost of an aero bar.

I've also been thinking that the 10 watts saved with an aero road helmet is probably the next best bang for the buck.

aeroisnteverything
Posts: 193
Joined: Fri Aug 24, 2018 4:43 pm

by aeroisnteverything

AJS914 wrote:
Wed Jan 09, 2019 6:26 pm

Of the 10% aero frame drag, I wonder what percentage is accounted for by an aero cockpit.
Spesh itself provided a useful data point on that, didn't they? See chart on page 17 of this thread: https://weightweenies.starbike.com/foru ... &start=240

Eyeballing those numbers, you get about 20% to 20% of the distance between tarmac and venge by switching to aerofly. That may be just one data point, but this means aroudn 2-2.5% of the overall drag.

aeroisnteverything
Posts: 193
Joined: Fri Aug 24, 2018 4:43 pm

by aeroisnteverything

double post
Last edited by aeroisnteverything on Wed Jan 09, 2019 6:47 pm, edited 1 time in total.

Jugi
Posts: 539
Joined: Sun Jun 24, 2018 8:10 am

by Jugi


AJS914 wrote:FWIW, the new Tarmac isn't what I'd call a "classic" frame. It has many of the same aero features of the Venge minus the hidden cables.
In my opinion it is a classic frame in essence. Although the tube shapes are not exactly round and the seatstays have been dropped, it is still very "slender" looking and dimensionally very close to the "traditional" road bike shape.

AJS914 wrote:Still, I'm not sure 3-5 watts is worth the $400-500 cost of an aero bar.

I've also been thinking that the 10 watts saved with an aero road helmet is probably the next best bang for the buck.
I have been contemplating the aero bar purchase for a while, and for now I'll stay on the fence so to speak. It's basicly like dropping the aerodynamic drag of two 15 cm long pieces of the frameset's leading edge to a third of what it is. If there is a tradeoff like being less comfortable on long rides because the aero bar might have different damping characteristics or different fit, my own drag will easily rise enough to defeat the benefits. I'll rather stick with a bar which feels like custom fit to me.

I haven't found any drawbacks from an aero helmet. Like the look, fit, noise level and ventilation.

aeroisnteverything
Posts: 193
Joined: Fri Aug 24, 2018 4:43 pm

by aeroisnteverything

Jugi wrote:
Wed Jan 09, 2019 6:45 pm


I have been contemplating the aero bar purchase for a while, and for now I'll stay on the fence so to speak. It's basicly like dropping the aerodynamic drag of two 15 cm long pieces of the frameset's leading edge to a third of what it is. If there is a tradeoff like being less comfortable on long rides because the aero bar might have different damping characteristics or different fit, my own drag will easily rise enough to defeat the benefits. I'll rather stick with a bar which feels like custom fit to me.
FWIW, I found a chinese knockoff (or someone from the factory, because it looks totally OEM, down to logos and everything) selling version of Canyon Aerocockpit on ebay for £80 on ebay a while ago and switched to that for my Ultimate. Best thing ever. This is of course subjective, but to me it's actually more comfortable in every conceivable position than the standard alloy shape, and has better damping qualities, because carbon, while not yielding much in perceived stiffness. And I went narrower by 2-3 cm (can't remember now) for even more aero boost. Plus the looks are of course great, and cables are tidier, and the whole thing is lighter than standard set up. As with your aero helmet situation: no drawbacks at all.

ichobi
Posts: 952
Joined: Thu Jan 19, 2012 11:30 pm

by ichobi

If you pick the right aero bar, it can be comfortable, nice looking, and of course, aero.

I tried a few -

1. Aerofly 1 - hate the shape, couldn't get the right fit whatsoever. Reach was too long.
2. Canyon Aerocockpit H11 - came with my Canyon Aeroad. Perfect fit. Comfort is alright.
3. Black Inc Bar Stem combo - Perfect fit, very good looking. Lots of size to choose from.
4. Cervelo AB03 - Nice shape, couldnt get the fit right. Reach was too long.

What you lose in absolute term is probably the stiffness. I came from Syntace CDR bar which is considered one of the stiffest on the market. I can feel in the sprint that my aerobars do give a bit compared to the Syntace. On the other hand, all the aerobar I tried feel more comfortable than the syntance. (Less shock)

The important thing to look for is how each bar measures the reach. They all measure quite differently. Got it wrong and you are in for a head ache.

spdntrxi
Posts: 3116
Joined: Sat Jul 20, 2013 6:11 pm

by spdntrxi

I tried a bunch.. my fav aerobar was Ritchey StreemII in carbon. tick'd all the boxes for me.

Imaking20
Posts: 2028
Joined: Fri Nov 18, 2011 5:19 am

by Imaking20

As much as I love to nerd out on aero (and have something of an aero bike addiction) - I think a lot of the fun comes from the details besides the frame. There has been information floating around the interwebs for awhile (like on aerogeeks) that challenges the significance of the frame in the equation.. but that's where manufacturers can get the most money out of you. It's cool to see more support for aero wheels and bars regardless of frame. Though, we've also got to be aesthetic weenies and aero bars shouldn't go on all bikes :)

I've run my share of aero bars as well and would agree the Ritchey Streem is very underrated. Stiff in a sprint, not abusive, and one of the lighter options. The first SES bars were terrible. Pro Vibe Aero has been good to me as of late - with a drop shape akin to the Deda Superleggera, an attractive finish, and respectable weight.
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Retired:
Wilier Wonka | The Dentist | The Bucket List | Specialissima | Evo | T2 | Blue | Project C6.0 | Felt AR FRD | Colnago C59 | S-Works Tarmac SL4| S-Works Venge | Wilier Cento1 SL | Tarmac SL2

KarlC
Posts: 942
Joined: Fri Dec 05, 2014 2:08 am
Location: San Diego Ca USA

by KarlC

What make a bar and aero bar ?

My normal road bar Easton EC90 SLX3 is 32mm at the tops + bar tape

My 3T Ergonova LTD Bar is 23mm deep at the tops and has more of a pointed front oval shape and under 170g

My Cervelo S5 reps is 20mm deep at the tops and has an even more pointed front

by Weenie


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