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PostPosted: Sat May 27, 2017 5:18 am 
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Joined: Sat Jun 02, 2007 1:10 am
Posts: 1852
Location: Melbourne, Australia
My thoughts -
Brands do not pay for big dollar marketing and sponsorship of pro teams/riders.
Customers do.
Brands do not pay "Made in USA" or other "premium" locations
Customers do.

Because customers are influenced by these things, big brands can do these things put their prices up to cover it.

When the marketing department gets too carried away and wants features over actually long term customer benefits in real world riding, you get things like ceramic coatings that wear off but market nicely, and light weight but un aero Al spokes, or worse carbon fiber spokes like R-SYS that are thick, un aero, and resulted in wheel instability of the spoke buckles in compression.
I read recently about some new tensioned carbon fiber spokes that are much thinner than R-SYS and build like "normal" wheels. If they do bladed spokes I might be interested.
http://www.abc6.com/story/35457725/tuff-cycle-launches-new-range-of-high-performance-competitively-priced-carbon-fibre-bicycle-wheels
Just because you are a big brand doesn't mean you have exclusive access to the latest developments. If you have good relationships with good factories you can still benefit from their knowledge and new tech.

If you crash any set of wheels no matter what you paid for them - they will fail. I kinda live by the theory - don't ride what you can't afford to crash. If you are an elite pro then yeah every last gram matters (and you don't have to pay for kit anyway), but for most of us getting within 5% of the best wheels will not make a noticeable difference. Hell just look at the pros who win on gear we know isn't the best out there.
For me I shop for value. I like good gear, but won't pay for the flash or the brand. You can get good stuff from any company that has invested in its brand - so that means stay away from no name Chinese wheels. They don't care if your wheels fail, they just get the cheapest rims from the cheapest factories and sell as many of them as they can before they disappear again and start as somebody else.


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PostPosted: Sat May 27, 2017 7:51 am 
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Joined: Sun Jun 18, 2006 10:29 am
Posts: 6676
Location: Athens, Greece
What does brand name really mean? Do you judge brands only by their size? By their marketing influence in the media? It's not that simple...
There are big brand wheels that are overpriced and others that are not. Zipp and Enve are overpriced IMHO. Campagnolo-Fulcrum and Corima are almost underpriced.

Nejmann wrote:
So my Lightweights are the A. Lange & Söhne of wheels? :D

LW is the Patek Philippe of wheels. 8)

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Posted: Sat May 27, 2017 7:51 am 


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PostPosted: Sat May 27, 2017 8:53 am 
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Joined: Wed Aug 18, 2004 6:06 pm
Posts: 252
Location: Lower Saxony - Germany
mpulsiv wrote:
stormur wrote:
BTW didn't I read recently somewhere that V shape is more aero than U shape ( again ? )


No, "U" shape has nothing to do with aero. The sole purpose to upgrade from "V" shape to "U" shape is for stability in crosswinds.
I questioned Victor from viewtopic.php?t=131368 as why he thinks we need to go back to "V" shape. His statement specifically applied to Venn Rev 507 (50mm) wheels. They couldn't form a true "U" shape with filament wound with deeper wheel. In contrast, Venn Rev 35 is true "U" shape.


Zipp marketing convinced us about the "U" shape being more stable in crosswinds:

Image

But that's not the case. ;) The last Tour test (8/2016) showed, that the tear drop shape of Mavic and Reynolds is more stable (less drag at the bars) and from personal experience I can support that.

BUT there really are - slight - aero benefits of the U shape in high yaw angels:

Image

Image

So very fast riders, which are generally in lower yaw angels, can pick the teardrop shape for more crosswind stability, slower riders can stick with "U" - but don't overestimate the influence of the shape: rim height is the most important factor. And avoid tire overhang.

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PostPosted: Sat May 27, 2017 11:25 pm 
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Tire overhang should be least of your worries whether you mount 23mm or 28mm tire on traditional narrow rim or modern wide rim. The delta is ~ 1 watt. Race on 25mm cotton tires and train on 28mm tires.

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PostPosted: Sun May 28, 2017 2:44 pm 
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Location: Lower Saxony - Germany
mpulsiv wrote:
Tire overhang should be least of your worries whether you mount 23mm or 28mm tire on traditional narrow rim or modern wide rim. The delta is ~ 1 watt. Race on 25mm cotton tires and train on 28mm tires.


On a narrow rim it doesn't matter that much, but on a wide rim you destroy the aero benefits:

Image

Image

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PostPosted: Tue May 30, 2017 11:34 pm 
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Joined: Wed Dec 30, 2015 12:41 am
Posts: 272
mpulsiv wrote:
Tire overhang should be least of your worries whether you mount 23mm or 28mm tire on traditional narrow rim or modern wide rim. The delta is ~ 1 watt. Race on 25mm cotton tires and train on 28mm tires.

1 watt per wheel at dead on head wind. A lot more different in cross wind as beaver's graph suggest though.

=================
beaver:

Silca blogs call that data as 105% rule where if rim is at least 105% as wide as tire then it wouldn't effect aero-ness of the rim at all. But data it established from is from U-shape rim test where brake track is significantly narrower than the widest section. Put a wide tire on there it'll be '8' shape instead of Toroidal 'U' shape as designer intended.

In the picture Zipp 404 (old) is 26.53mm wide at the widest point. 105% rule suggest tire size at or narrower than 26.53/1.05=25.02mm which is pretty close to 24.72mm that is brake track width.
23c (24.8mm) and 25c at 6bar pressure (26.1mm) are both still perform very good despite being a bit wider than brake track. Also, from FLO's yaw data record we shouldn't care about wind at 15 degree yaw or more at all as it is very rare when we are going high speed so the 25c at 7bar (26.5mm) should also be quite good in aero-ness too except in extreme yaw angle wind of course.

So i think for V-shaped rims the 105% rule could be relaxed since the widest part of the rim is on the brake track itself. Tire overhang of 0-1.4mm over brake track is just extension of the delta shape that wouldn't effect aero-ness much.

what do you think?


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PostPosted: Wed May 31, 2017 7:08 am 
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Posts: 252
Location: Lower Saxony - Germany
The 105% rule was initiated by Bontragers aero tests: https://www.google.de/url?sa=t&rct=j&q= ... cA&cad=rja

When the rim is wider than the tire at the brake track, the airflow will be led around the rim instead of loosing connection directly at the tire in crosswinds:

Image

The Zipp and Easton rims shown would be dramatically better with narrower tires (on the front, on the rear a little tire overhang is even better)...

This positive effect is also measured here with a Roval CLX 64 wheel:

Image

As the torodial rims are thinner at the brake track, wider tires will have a worse effect than on a V shape rim with a wide brake track. I am running U shape 28mm wide 21C NOX S36R rims with a 25mm tire (real width 28.5mm) and the transition is quite smooth. So yes, with little tire overhang everything will be fine.

With 23mm tires my rims would be better aerodynamically, but I need some mm more for the bad roads. :(

Image

Btw. I have a collection of my links here: http://forum.tour-magazin.de/entry.php? ... ynamik-etc

My text is german but the links will bring you to english sites. :)

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PostPosted: Mon Oct 30, 2017 1:13 pm 
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Joined: Sun Dec 29, 2013 3:44 pm
Posts: 57
Location: heaven, EU
difrences are usually in QC , reliability, innovations, resale value.

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PostPosted: Mon Oct 30, 2017 3:22 pm 
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Joined: Tue Jan 28, 2014 6:52 pm
Posts: 1475
All these marketing points are made with data at 12-20 degrees yaw which most cyclists rarely see. If they talked about 3 or 5 degrees people would see that there isn't a huge difference between all these rims.

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