Zipp SL-70 Aero

Discuss light weight issues concerning road bikes & parts.
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Waldo
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by Waldo

I'd say 6 Watts constitutes "quite well." Your assumptions that the data was obtained without rider and that the presence of a rider negates any aerodynamic effects are both incorrect.
ENVE contract engineer | Former Zipp test engineer


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ergott
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by ergott

Waldo. How does hand position and the installed brake levers come into play? I know you guys are pretty thorough with your aero data.

Thanks

dunbar42
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by dunbar42

Waldo wrote:I'd say 6 Watts constitutes "quite well." Your assumptions that the data was obtained without rider and that the presence of a rider negates any aerodynamic effects are both incorrect.


I'm just saying it would be nice to see that data to support the claim. Many of the claims made about aero gear turn out to be exaggerated when you look at the wind tunnel results.

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Waldo
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by Waldo

Ergott, I don't have access to the data anymore, but my recollection is that hand position didn't affect the results. We did see some interesting things with hand position relative to different bar widths but that data hasn't been released and I'm not at liberty to discuss it. This testing was only done with SRAM levers (non-hydro). I suspect that the difference going to a larger lever assembly like the hydro would be lost in the resolution of the tunnel.

Dunbar42, if you would like the data contact Zipp. I'm not sure what you're getting at stating marketing claims being exaggerated relative to wind tunnel data, since we're clearly discussing tunnel data at this point. If you're trying to insinuate that there's some manipulation of the data, that's completely off-base. All you need to do is look at historical data Zipp has released relative to magazine and even manufacturer tests to see Zipp has been conservative with data. Most of the recent data from other companies removes the strut tare from the data, which I certainly think is incorrect (it was never done with our data). That's why you see some of these relatively shallow rims yielding "negative" drag.
ENVE contract engineer | Former Zipp test engineer

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djconnel
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by djconnel

A traditional round-tube section creates drag of about 0.74 Newtons, which we found requires about 7.5 watts of effort at 30mph (48.3kph) to overcome. The airfoil developed in CFD that is used in the SL-70 Aero handlebar creates just 0.11N of drag, which means a savings of 6.4 watts over a round-tube section.

Language is a bit ambiguous. One interpretation is that the reported force is only the force on the bars. But rider drafts off handlebars. Round bars provide better draft. So question is what is the net force, rider + bars.

This language is open to other interpretations. Another interpretation would be the net force was 0.11N relative to bars with only drops, no top at all, but the force included the rider.

bfno
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by bfno

TBH I have the VukaSprints and as nice as they look there really is no substitute for a nice round bar. Found the quite flexy (not sure about how the new ones are) and the tops are uncomfortable as it is a sin to put tape on them!
Venge | Shiv TT | Langster | Dogma 60.1 | CruX | Aeroad CF SLX (WIP)

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ergott
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by ergott

djconnel wrote:Round bars provide better draft.


When aero matters your hands are supposed to be in the drops. The tops of the bars don't really have anything behind them until your knees.

Speedypalmer
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by Speedypalmer

Has anyone weighed a 40cm pair?

Thank you.

L84AD8
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by L84AD8

Speedypalmer wrote:Has anyone weighed a 40cm pair? Thank you.

My 380mm came to 224g, sorry not 400mm but I'd guess it's 10~20g more.. HTH :)

Speedypalmer
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by Speedypalmer

And are the Zipp bars any different from the S-works Aerofly's? Thinking the stealth black look of the s-work bars will be a better match to my new steed!

dmoneysworks
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by dmoneysworks

I got a 40cm bar and weight was 233g

DaReef
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by DaReef

Since you bumped.

I love this bar. Extremely comfortable in the drops and on the tops. I've riddin 125m ride a few times. Plenty stiff. I have it on two of three bikes. Don't have weights but both bikes are in the 15-16lb range.

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Last edited by DaReef on Sun Dec 25, 2016 7:37 am, edited 1 time in total.

itguy
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by itguy

Does it work well with kedge mounts?

Sent from my SM-G930F using Tapatalk

dmoneysworks
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by dmoneysworks

I just ordered my SL sprint stem and hoping that my SRM PC8 Computer mount fits as easily as a garmin one :)

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MJB
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by MJB

I have the 40cm C to C version of the SL-70 Aero - with a Zipp Service Course stem it just fits with a tiny amount of flexing in the clamp angle onto a cheap and nasty double arm light bracket. The clamps on the bracket are an overly fat 84mm wide each so the fancier K-Edge and Garmin / Bar Fly mounts should fit easily on even the 40cm model. I had a 44cm model and there was significantly more space between the headstem clamp and where the bar curve profile starts.

The SL-70 Aero is equally as good at high frequency vibration reduction as the Oval R910 but the ergonmics and cable routing are far superior than the Oval R910.

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