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Re: 2014 Felt AR [berkeley] [ In reply to ]
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berkeley wrote:
Dave, is the frame compatible with internal batteries for di 2 & eps?

For Di2 yes, there is a special carrier mounted to the InternaLoc seatpost binder that captures the Di2 battery and allows it to use a fixed cable length so saddle height adjustments are not tethered to the e-tube wire. For EPS, the internal power unit was designed around a 27.2mm round post. It will fit in the seat tube of the 54 thru 61cm sizes but not the 48 and 51cm. The two smaller sizes need to have the PU o-ringed with foam insulation and dropped thru the head tube into the downtube. The charging port is capped with a small hole under the BB shell.

Campagnolo has yet to make production Power Units available so we'll use the external PU for the AR3 EPS and mount it under the downtube just in front of the BB and somewhat sheltered by the crankset.

-SD

Dave Koesel - Category Leader Roval, Power, On-bike Components
https://rovalcomponents.com/
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Re: 2014 Felt AR [SuperDave] [ In reply to ]
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@SuperDave: Thanks for the info above - very interested in the AR FRD frameset.

Two questions:
1. Could I ride 25mm tubulars (say veloflex arenberg/roubaix) on firecrest 404s or 303s?

2. Where can I test ride one (When I called the customer service line I was told that nobody would stock the FRD in the Seattle area)?

thanks,

Naisan
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Re: 2014 Felt AR [SuperDave] [ In reply to ]
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Did the s5 have the Zipp Vukasprint handle bar also?
Did both bikes have the same wheels?
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Re: 2014 Felt AR [naisan] [ In reply to ]
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naisan wrote:
@SuperDave: Thanks for the info above - very interested in the AR FRD frameset.

Two questions:
1. Could I ride 25mm tubulars (say veloflex arenberg/roubaix) on firecrest 404s or 303s?

2. Where can I test ride one (When I called the customer service line I was told that nobody would stock the FRD in the Seattle area)?

thanks,
Naisan

Yes, I'm running 25mm tires on my AR1 bike now. The frame was designed with wider rims and tires in mind. I won't know where you can test ride one until they start to ship to dealers. Tough to predict their location before production starts. Any Felt Dealer can order them. They will ship in the order they've been sold, then stocking orders are fulfilled.

-SD

Dave Koesel - Category Leader Roval, Power, On-bike Components
https://rovalcomponents.com/
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Re: 2014 Felt AR [SuperDave] [ In reply to ]
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Do you know anything about shipments to Europe?

I am quite eager to get one, but I live in Sweden, which is entirely devoid of Felt-dealers, so the closest possibility that I see would be to order one from e.g. UK, where there are some mail order firms that have been selling them so far (such as sigmasport.co.uk). Or do you see any other possibility for me to buy one over here?

- - - - - - - - - - - -
The best beer is the one in front of you
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Re: 2014 Felt AR [SuperDave] [ In reply to ]
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Hi SD,

Any update on that white paper?

Thanks,
Alex
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Re: 2014 Felt AR [alexZA] [ In reply to ]
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Is this new information on aerogeeks legit? http://aerogeeks.com/...unnel-data-analysis/

like this:



or this:


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Re: 2014 Felt AR [naisan] [ In reply to ]
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I'm bumping this up because I am curious about the aerogeeks report as well. If all is as it seems it is a very compelling argument for the Felt AR. The only thing that I would have like to see in addition to what is there is a comparison of 2 round water bottles on the frames.
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Re: 2014 Felt AR [pyrahna] [ In reply to ]
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bump
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Re: 2014 Felt AR [naisan] [ In reply to ]
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naisan wrote:
Is this new information on aerogeeks legit? http://aerogeeks.com/...unnel-data-analysis/

like this:

or this:

Legit for a bike without a rider. That is the main caveat. Put a rider on there and I am sure the difference won't be 40W! Seriously that is 15-20% of the power most of us will do ironman legs at! I doubt there is 40W available to improve by, I make it at least half the difference between my Tarmac and my Shiv TT, don't believe it will translate to real world performance. 5-10W I would believe.
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Re: 2014 Felt AR [JG] [ In reply to ]
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SuperDave, Care to give us any details on the Felt brake used in the second run (and what you use on your own bike)? Similar to a TriRig Omega I assume. Quite impressive results, I might add!
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Re: 2014 Felt AR [Nigel] [ In reply to ]
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Quite impressive data. I am surprised ST has discussed the above data more. I guess the bike doesn't have a French e' in its name.





Nigel wrote:
SuperDave, Care to give us any details on the Felt brake used in the second run (and what you use on your own bike)? Similar to a TriRig Omega I assume. Quite impressive results, I might add!

From another forum regarding what SD rides:

[quote="SuperDave"]

I'm running one of our IA brake calipers on the front of my AR1 as I'm typically riding 90 minute parking lot crits, not Alpine descents so giving up a few feet of braking distance doesn't concern me if I can shorten the finish line by a few feet gaining aero performance.

-SD[/quote]
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Re: 2014 Felt AR [Nigel] [ In reply to ]
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from post 104 above, superdave's brakes from sideview don't seem like a tririg omega, but hoping superdave will tell us.

From the weightweenies thread clip pisted above, I think dave is using the IA tri bike's caiper, exposed. After looking at Omegas tririg brake tunnel curves, I think tririg would be faster yet.

The pictured propel was not a SL0, so seems to use a standard bar/stem (compare pics on the giant website to the aerogeeks page). THat may explain the propel's test results vs their own tests, but would a bar/stem give that much up? It looks like the propel also uses shifter cables wheras the sl0 uses di2 electronic run in the bar, so all of this may add up to indicate that the sl0 may be lots faster than the sl1 in the tunnel, closing the gap between the felt and the propel.

would love to see the whole report, and hopefully good pics of the configs used to figure it out.

nice to have all of these aero options out there. . .;-)
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Re: 2014 Felt AR [naisan] [ In reply to ]
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naisan wrote:
from post 104 above, superdave's brakes from sideview don't seem like a tririg omega, but hoping superdave will tell us.

From the weightweenies thread clip pisted above, I think dave is using the IA tri bike's caiper, exposed. After looking at Omegas tririg brake tunnel curves, I think tririg would be faster yet.

The pictured propel was not a SL0, so seems to use a standard bar/stem (compare pics on the giant website to the aerogeeks page). THat may explain the propel's test results vs their own tests, but would a bar/stem give that much up? It looks like the propel also uses shifter cables wheras the sl0 uses di2 electronic run in the bar, so all of this may add up to indicate that the sl0 may be lots faster than the sl1 in the tunnel, closing the gap between the felt and the propel.

would love to see the whole report, and hopefully good pics of the configs used to figure it out.

nice to have all of these aero options out there. . .;-)

I believe the picture of superdave's bike is with the Campy center pull brake that comes with the campy AR.

Yes, an aero handle bar makes a big difference. But the Felt testing was done with a zipp vuka sprint, which is aero, so I do not think the giant handlebar/stem would have changed much.
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Re: 2014 Felt AR [naisan] [ In reply to ]
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I don't think the Propel is losing anything in the test as the Propel's Giant bar was replaced by a Zipp Vuka Sprint which is a pretty aero option. I just think Felt was a little fairer to all the other models giving them the Aero Zipp handlebar as well. So the Giant may have stayed in relatively the same place...it's just the competitors moved forward with the aero bar being placed on. Just my opinion.

Overall I think this is starting to shape up to be a pretty fair test. My biggest question so far is what do the frames look like with two round bottles on them against each other? Does the squashing of the trailing edge of the S5/propel's downtube help a ton in this case or not?
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Re: 2014 Felt AR [pyrahna] [ In reply to ]
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Hi pyrahna,

Great question about the bottle. And as someone else said, with a mannequin.

And as Gerard used to say, it's nice to finish second in everyone else's test. ;-)

Cheers,

Damon Rinard
Engineering Manager,
CSG Road Engineering Department
Cannondale & GT Bicycles
(ex-Cervelo, ex-Trek, ex-Velomax, ex-Kestrel)
Last edited by: damon_rinard: Sep 27, 13 12:32
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Re: 2014 Felt AR [damon_rinard] [ In reply to ]
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Damon-
I know you have talked quite a bit about the interaction of the mannequin with the Kamm seattube of the P5 and that the Kamm tail helps to organize the inherinetly disorganized air back there behind the riders legs and rear end. This makes a tremendous amount of sense to me. How influential is a mannequin on a bike that has fairly conventional tubesets aero shaping like the upcoming S3 and by reference the Felt AR? For the purposes of this discussion I am calling an airfoil with a leading edge, symmetric chord and a fully formed tail coming to a point a 'conventional' aero shape. i.e. no Kamm tails and straightish seattubes.
thanks for the response
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Re: 2014 Felt AR [pyrahna] [ In reply to ]
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Hi pyrahna,

Great question, and unfortunately there's not a simple answer.

Fully formed airfoils are great IF...
- They have the right shapes. Not any shape that looks like an airfoil is a good foil. And even the perfect airfoil shape is only perfect in the flow conditions in which it is perfect. That's why at Cervelo we do the hard engineering work of developing different foil shapes for the various different flow conditions the different parts of the bike sees. We call it Aero Zone engineering. Makes sense when you think about it, but it also demonstrates that a "signature" tube shape (one used everywhere on the bike), even it it's perfect in one place, is by definition imperfect in all the other places...
- They have the right aspect ratio.
- They converge appropriately. This is a big one. I can write about it more later...

Truncated foils are great IF...
- They have the right shapes.
- They converge appropriately.
- They are truncated in the right place. It's incredibly difficult to find the right place - truncating a foil, even based on careful theory, even based on Herr Doktor Wunibald Kamm's original theory, usually results in an increase in drag. It takes a lot of engineering power (in the physics sense, work per unit time) to develop a truncated foil that has less drag. But a truncated foil, in the right place, in relation to other bodies nearby, can change the flow in potentially useful ways, even if it initially increases the drag. The P5's and new S3's truncated seat post and seat tubes make good use of this. By the way, not sure you know this but the new S3 also has truncated dow tube (built for bottles) and head tube (the front brake Aero Zone establishes the airfoil thickness that leads to it).

But to answer your questions, typically non-aero bikes rank more or less the same with and without a rider. The magnitude of differences can change, so bikes that rank close sometimes flip flop.
It's aero bikes that can sometimes change rank order with a rider. And sometimes flip flop, as with non-aero bikes. I'm not including the new AR here, since I've not had the chance to measure one yet.

Cheers,

Damon Rinard
Engineering Manager,
CSG Road Engineering Department
Cannondale & GT Bicycles
(ex-Cervelo, ex-Trek, ex-Velomax, ex-Kestrel)
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Re: 2014 Felt AR [damon_rinard] [ In reply to ]
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I guess I am surprised to hear that delta's change with a rider aboard. I'm certainly not questioning your knowledge or experience, I'm just surprised. I guess it makes sense if you design the bike to try and make up for some of the rider's inherent bad shaping, but the P5's seattube being a Kamm tail is the first I have heard of someone trying to clean up the rider's wake with the frame. Maybe others are doing and either not knowing they are or not publicly stating they are.

I certainly would be interested in reading about converging the airfoils. This is one area that seems to be ripe for experimentation.
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Re: 2014 Felt AR [pyrahna] [ In reply to ]
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Hi pyrahna,

Yep. That's one of the reasons we have basically stopped testing without a rider. Bike aerodynamics is messy. One aerodynamicist compared testing a bike to testing an airplane with 59 control surfaces! So for sure, even if the designer isn't doing it on purpose, there are rider interactions that change the rankings a bit.

Interestingly, the P5's truncated seat post and seat tube is only one (two?) feature that affects the flow around the rider. We just haven't chosen to reveal the others publicly. ;-)

Rate of airfoil convergence is something we missed through years and years of wind tunnel testing, even at the accelerated pace of testing more ideas faster, which we finally got to around 2007 or so when we started using our test mule's quick-change skins. No, we needed our full time aerodynamicist and validated CFD to finally get it. :-)

Cheers,

Damon Rinard
Engineering Manager,
CSG Road Engineering Department
Cannondale & GT Bicycles
(ex-Cervelo, ex-Trek, ex-Velomax, ex-Kestrel)
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Re: 2014 Felt AR [damon_rinard] [ In reply to ]
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damon_rinard wrote:
That's why at Cervelo we do the hard engineering work of developing different foil shapes for the various different flow conditions the different parts of the bike sees. We call it Aero Zone engineering

Hi Damon,

Can you comment on the airfoil developping process? Do you use standard NACA airfoils and you just play with the aspect ratio and the truncation points or you develop fully custom airfoils?

http://cds-0.blogspot.com
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Re: 2014 Felt AR [damon_rinard] [ In reply to ]
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damon_rinard wrote:
I'm not including the new AR here, since I've not had the chance to measure one yet.

If you guys are headed to SD in the next month or so maybe we could exchange some equipment in a gentlemen's agreement. Our on-bike rider isn't static like your DaveZ dummy and you don't have an AR. We only published the data collected that was deemed legally acceptable by our global sales team. Competitor comparisons are much trickier outside the USA. As for the dummy and our new AR, perhaps we could swap/share for a couple hours?

As I said previously in this thread, the S5 still sits atop the heap at low yaw; no doubt the head tube, seat tube/stay/post you have works wonders here. I know you've tested our previous AR designed in 2007 and would agree it still was a good option for those looking for aero as a higher metric over weight, stiffness, and ride compliance (Cervelo notwithstanding). We certainly had gains with the new bike's aerodynamics but it is the torsional stiffness and cockpit comfort I'm most pleased with. A back-to-back "parking lot" test ride between the old AR and and the new model won't show the consumer the aero gains but those two categories put the bike in a new realm.

The new AR is no longer an aero road bike. It's just a road bike. Period. A modern bike must be aero to be considered "modern". Same with wheels, helmets, clothes, etc...

In any case, the comment about finishing 2nd in everyone's test isn't really valid here. Cervelo was indeed the lowest drag on -5/0/5 and very close with -10/0/10 average. Of course the fit of the two bikes is very different, too so that factor may play as important role as any for consumers.

Thanks for your contribution here.

-SD

Dave Koesel - Category Leader Roval, Power, On-bike Components
https://rovalcomponents.com/
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Re: 2014 Felt AR [SuperDave] [ In reply to ]
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Dave-
Would it be possible to give us a link to the whitepaper that aerogeeks referenced?
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Re: 2014 Felt AR [Epic-o] [ In reply to ]
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Hi Epic,

We started with NACA foils and progressed to developing our own using our test mule in the wind tunnel and different kinds of CFD. Would love to describe more but don't want to give away too many secrets. ;-)

Cheers,

Damon Rinard
Engineering Manager,
CSG Road Engineering Department
Cannondale & GT Bicycles
(ex-Cervelo, ex-Trek, ex-Velomax, ex-Kestrel)
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Re: 2014 Felt AR [SuperDave] [ In reply to ]
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Very generous offer Dave, thank you. Will certainly run it by our crew here. We actually just returned from the tunnel this week so it's not likely we'll be there again until a few months later.

Cheers,

Damon Rinard
Engineering Manager,
CSG Road Engineering Department
Cannondale & GT Bicycles
(ex-Cervelo, ex-Trek, ex-Velomax, ex-Kestrel)
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