2015 'PRO' cycling discussion

[stuka666]

After the Katusha case, now Astana.. no more "Russian" teams?

[DanW]

This may have already been covered in the road forum... but what do we reckon to Cervelo's claims that a handlebar accounts for 30% of the bike's total drag and this bar saves 4.4 watts over a conventional round bar? As with anything aero it all depends on the conditions I guess, but it sounds like a big claim. A bar accounting for 30% of the bike's total drag sounds like a lot too.

[maquisard]

30% actually seems like a realistic figure when you consider the frontal area of the bars in comparison to say, the wheels or frame. I think Cervelo went as far as to say that the improved aerodynamics of the new S5 came only from the new bar and not the frame, the latter of which had similar performance to the previous iteration.

Having the Garmin in that position above however more or less negates any of the benefits of the Cervelo aerobar!

[DanW]

Di2 junction, bar tape material... lots of things could be tweaked if you went full aeroweenie I guess

[djconnel]

Typical CdA for bike + rider = 0.32 meters squared = 3200 cm^2. A bar is around 44 cm across (o-o) with maybe 15 cm drop on two sides so that's 74 cm by 2.6 cm multiplied by a cylindrical Cd of around 1 = 194 cm^2.



Bike CdA can be calculated from wind tunnel drag, using drag = 1/2 rho CdA v^2 in appriopriate units:



The Cervelo's around 870 grams @ 30 mph, which converts to a CdA, assuming 1.2 kg/m^3 for air density rho:
You have: 2 * 870 grams * gravity / ((1.2 kg/m^3) * (30 mph)^2)
You want: cm^2
* 790.59379

So I calculate 194 for the bars, 790 for the whole bike:
You have: (2.6 cm * (44 + 2*15) cm) / (2 * 870 grams * gravity / ((1.2 kg/m^3) * (30 mph)^2))
You want: %
* 24.336138
/ 0.041091153

That's 24% using a very crude calculation, not counting shift levers.

[lippythelion]

It's not very pretty
Looks very aero from the front.

[nathanong87]

right now 2.5/10 wiggos. But i aint care. #MCE


dat slumber filter

[Samuel Sanchez Gonzalez]

Soon will need to size up the jersey! Good to see him a bit bulky

[DuncanS]

30%

Having the Garmin in that position above however more or less negates any of the benefits of the Cervelo aerobar!

Pretty sure I read somewhere that their aero numbers actually improved with the garmin mounted there.

[nathanong87]

how many WT races has cervelo won this year? I'd say canyon has the most aero bar....

[IchDien]

how many WT races has cervelo won this year? I'd say canyon has the most aero bar....

I haven't seen any WT/Conti Cervelo sponsored teams using the bar.

[nathanong87]

so zero! =P

zomg he got that pro tenderloin status

[53x12]

Having the Garmin in that position above however more or less negates any of the benefits of the Cervelo aerobar!

Garmin tests faster on top of the stem rather than in front of the handlebar.

[wingguy]

I haven't seen any WT/Conti Cervelo sponsored teams using the bar.

I have. There's a photo of one 9 posts before yours.

(Also, of course you haven't seen any WT Cervelo teams using it )

(Also also, of course you haven't seen any Pro-Conti Cervelo teams using it. Their cockpit space is paid for by 3T )

[djm]

What about the Di2 junction box? Seems to add a fair bit of drag as well.