Zipp 454 NSW reviews

Discuss light weight issues concerning road bikes & parts.
nemeseri
Posts: 685
Joined: Tue Apr 07, 2015 5:40 pm

by nemeseri

Beaver wrote:In addition to the 25mm tires they should have tested the recommended tire size. The CLX 64 suffer a lot with wide tires


thumper88 wrote:This part is the only thing he's right about -- and it's one huge reason the test is nearly useless. That "25m but really sometimes 29mm" tire stalled out a lot of wheels and at really shallow angles....and it probably had a really bad shape in addition to a bad size for stalling wheels.


But the roval clx is probably the widest wheel in the test (21/29.9) and it was second worst at 5deg. They designed it to be this wide especially to accommodate wider tires and minimize the aero hit.

Also I call BS on 35W difference between the roval and enve at 5deg yaw. Just think about it, even at 30 mph, that's crazy.

User avatar
cyclespeed
Posts: 585
Joined: Mon Jun 06, 2016 8:45 am

by cyclespeed

nemeseri wrote:Also I call BS on 35W difference between the roval and enve at 5deg yaw. Just think about it, even at 30 mph, that's crazy.


You're not the only one!

by Weenie


Delorre
Posts: 961
Joined: Sat May 24, 2014 12:09 pm

by Delorre

cyclespeed wrote:
nemeseri wrote:Also I call BS on 35W difference between the roval and enve at 5deg yaw. Just think about it, even at 30 mph, that's crazy.


You're not the only one!


Some time ago GCN did a test : "stock" alloy wheels vs Zipp 808 @ ~ 41 km/h. Power needed went from ~380w to ~345w, so about 35w gain, so, no way there is 35w diff between the Rovals and the Enve's in real world circimstances.

https://www.youtube.com/watch?v=pUdC3mrHcc8

hambini
Posts: 133
Joined: Tue Nov 15, 2016 8:13 am

by hambini

The bike radar review has some seriously questionable data in it. If I saw that data in my professional capacity I would dismiss it - the explanations they give about "aerofoils" stalling makes me cringe!

The vast majority of drag reduction comes from how deep the section is. The use of a "toroidal" profile is not going to make much difference in comparison to the section depth. There are also marginal gains to be had from the spokes but it is only small when the wheels are deep.

I have tried to explain in this video the aerodynamics behind wheels as opposed to picking an outright winner. It's long but quite in depth

https://youtu.be/BUih_emc54M

thumper88
Posts: 146
Joined: Tue Mar 13, 2012 7:27 pm

by thumper88

nemeseri wrote:
Beaver wrote:In addition to the 25mm tires they should have tested the recommended tire size. The CLX 64 suffer a lot with wide tires


thumper88 wrote:This part is the only thing he's right about -- and it's one huge reason the test is nearly useless. That "25m but really sometimes 29mm" tire stalled out a lot of wheels and at really shallow angles....and it probably had a really bad shape in addition to a bad size for stalling wheels.


But the roval clx is probably the widest wheel in the test (21/29.9) and it was second worst at 5deg. They designed it to be this wide especially to accommodate wider tires and minimize the aero hit.

Also I call BS on 35W difference between the roval and enve at 5deg yaw. Just think about it, even at 30 mph, that's crazy.



Specialized most definitely did not design the wheel for extra wide tires. For aerodynamics, the shape of it wants 23mm or so, with a decent profile. Look at the tunnel data from blather about bikes... the s-works 22mm works the best, the 24mm next best.
It's widest well back from the tire, unlike the slab-sided designs of say zipp and HED. You want the wind to flow around the leeward side and stay attached... in this case you want to try to keep that section shape looking like an aircraft wing rather than the body of a wasp.... smaller tire will do that, 25mm and up creates a hollow right behind tire on leeward side and the wheel stalls out. And the effect is magnified the further the apparent wind direction shifts from zero degrees.
Same thing happens when you go too large on a Zipp but likely the U-shape is at least somewhat less susceptible to that effect, up to a certain point in tire size.
This likely explains this BS results in this test.

User avatar
mpulsiv
Posts: 1040
Joined: Mon Mar 24, 2014 9:17 pm

by mpulsiv

Moral of the story - forget Zipp! Keep thousands of dollars in your pocket and use pocket change for modern ~ 30mm aluminum wheels www.novemberbicycles.com/blog/2017/2/9/ ... lloys.html
Racing is a three-dimensional high-speed chess game, involving hundreds of pieces on the board.

:arrow: CBA = Chronic Bike Addiction
:arrow: OCD = Obsessive Cycling Disorder

Shrike
Posts: 1259
Joined: Fri Jun 03, 2016 5:08 pm

by Shrike

Best part of that article above is the comment saying that '10mph wind is serious'.

I want to move to wherever that guy lives :lol:

So these HED 6/9s according to Bikeradar are the business then if you want a fast wheel and are priced out of ENVEs. Interesting. Just a shame about that ugly ass alloy rim. Aesthetics are important of course, but if you're purely looking for a fast beater wheel then it's hard to argue against the HEDs.

User avatar
cyclespeed
Posts: 585
Joined: Mon Jun 06, 2016 8:45 am

by cyclespeed

Shrike wrote:Best part of that article above is the comment saying that '10mph wind is serious'.

I want to move to wherever that guy lives :lol:

So these HED 6/9s according to Bikeradar are the business then if you want a fast wheel and are priced out of ENVEs. Interesting. Just a shame about that ugly ass alloy rim. Aesthetics are important of course, but if you're purely looking for a fast beater wheel then it's hard to argue against the HEDs.


Given their total lack of credibility in these kind of tests, I wouldn't make any decisions based on them if I were you.

I remember they did one on aero helmets a while back and rubbished anything Giro. Giro went apeshit and they had to issue a statement.

I mean the guy says Campagnolo wheels would be 'cannon-fodder' for Christ's sake, I stopped listening at that point.....

Post Reply
  • Similar Topics
    Replies
    Views
    Last post