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Discussion Starter · #1 ·
Now that I am starting to race some stage races and TT's (they are really fun!) I probably need to get a set of wheels at some point. I doubt my Campy Neutrons are all that aero, and at 25+mph in a TT, I am told it makes a difference. Ideally I would like to use the wheels as a general road-race wheel as well.

Due to pricing and team sponsorship, I am looking at both the Easton 58mm wheel, and the Reynolds Stratus DV, which is 38mm. How much faster is the 58mm in a TT situation? I saw the results posted somewhere of an analysis in a TT of a 40mm wheel, so I assume a 50+mm is going to be even faster in a TT situation (the obvious tradeoff being lack of stability in a crosswind). In the event of a windy day, I could always ride the Neutrons. FWIW, I am 150lbs at most.

Will there be a noticeable differerence between a 38mm Reynolds and 58mm Easton wheel in a TT situation? How much time, say a 20K time trial averaging 45km/hr? I know it doesn't mean much in a regular road race, and the Reynolds are regarded as stronger. Ideally, maybe 50mm would be best, but I don't have the $ for Boras!
 

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Discussion Starter · #2 ·
I just checked the Reynolds website (I was told they were 38mm) but in fact, they are 46mm. This sounds like a poor-man's Bora! Probably exactly what I would want for an all-around wheel. Plus the sponsorship price is only $200 more than a set of Eurus! Any disagreement?

My current thinking is that I keep the Neutrons for training and windy races, sell my Eurus, and get the Reynolds for non-windy races and the TT's. The new Eurus don't seem to be any more aero than the Neutron, and about the same weight. Plus, the ride is harsher. The old Eurus were more of a departure from the Neutron-I wonder why they changed design?
 

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Reynolds Stratus DV's are a good choice. From all accounts the rim is uber tough. On eBay, now, there are a few sets for sale, some of them coming with White Industries LTA hubs. New Reynolds wheels come with hubs from one of the Far Eastern manufacturers. I don't know if they're manufactured to Reynolds' specs or if they're off the shelf items. Picking up one of the DV sets w/ LTA hubs on eBay would be a great deal.
 

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dawgcatching said:
I just checked the Reynolds website (I was told they were 38mm) but in fact, they are 46mm. This sounds like a poor-man's Bora!
It's nice to know that the world is so prosperous that even the "poor" people are throwing down way over $1,000 for a set of bike wheels!

My whole bike is worth less than that... but I already knew I was living well below the poverty line...

Why are they using Laser spokes instead of CX-rays? Seems like a strange way to cut costs...

Hey Alienator... you know who is making those hubs for Reynolds?
 

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rruff said:
It's nice to know that the world is so prosperous that even the "poor" people are throwing down way over $1,000 for a set of bike wheels!

My whole bike is worth less than that... but I already knew I was living well below the poverty line...

Why are they using Laser spokes instead of CX-rays? Seems like a strange way to cut costs...

Hey Alienator... you know who is making those hubs for Reynolds?
Yeah, but you can get a used set cheaper than a grand. Or you can go whole hog and get Stratus DV-UL's for $1900 deneros and walk a away w/ an 1150ish gram wheelset.

I asked the same thing of Ligero re: Lasers vs. CX-Rays. His thought was, and it is true, that the Lasers offer better aero qualities at all angles of incidence, whereas the aero properties of CX-Rays get worse as the angle of incidence increases....much worse. Outside of that, there's not much difference between the two spoke types other than cost and profile.

As for the hubs, my guess would be Joytech, but that would be just a guess. Personally, I think the Reynolds wheels would be muy hot w/ White Industries H1 hubs and Pillar Ti spokes. Hell, with that combo on DV-UL rims, you could have a wheelset that was right at 1000g or so (20F/24R) that would be pretty damned durable. I picture that same, fantasy wheelset every night before I go to sleep.....see, it's my own little self-actualization program.
 

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alienator said:
I asked the same thing of Ligero re: Lasers vs. CX-Rays. His thought was, and it is true, that the Lasers offer better aero qualities at all angles of incidence, whereas the aero properties of CX-Rays get worse as the angle of incidence increases....much worse.
Any source for that info? I would expect a narrow oval spoke to have less drag at any angle of incidence that you could ride in... circular cross sections suck.
 

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rruff said:
Any source for that info? I would expect a narrow oval spoke to have less drag at any angle of incidence that you could ride in... circular cross sections suck.
You can't say absolutely that circular cross sections suck. You have to consider the angle of attack of the relative wind. For any given angle, the circular cross section will have the same flow characteristics for a given Reynolds number (This does not take into account where that round spoke is with respect to the rest of the rim and the wind. Presume that the spoke is not in the wake of any other object.). CX-Rays are 2.3x0.9mm on the bladed section, while Lasers are 1.5mm in diameter. As the angle of attack increases on the CX-Ray, turbulence increases, and eventually flow completely detaches and is totally turbulent. This is easty to imagine: given a perfect crosswind, that CX-Ray looks like a flat plate 2.3mm wide, a shape that will generate much more drag than that 1.5mm spoke. I'm willing to bet that CX-Rays aren't optimized for high or even moderate angles of attack. If they were, they'd perform decidedly better at one angle, alpha, while at -alpha they'd be kack. Now I don't know what that angle would be, but given experience with STOL aircraft, I'm willing to bet that angle is less or much less than +/- 25 degrees or so. Beyond that critical angle, drag on the bladed spokes will quickly surpass that on the round spokes as the angle increases. Also, all of this assumes that the bladed spoke is perfectly oriented. Since that's highly unlikely, it means that drag won't be uniform across the spokes given the same angular position for a spoke in question.

I've seen studies of this cited, and I wish I could remember where I saw them. Alas, most of my hard drive is taken up with optical research.

I don't know what you mean by angles under which people can ride. It's not a function of angle, as much as it is a function of air speed coupled to angle. It's perfectly feasable to ride with a perfect crosswind.
 

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alienator said:
I don't know what you mean by angles under which people can ride. It's not a function of angle, as much as it is a function of air speed coupled to angle. It's perfectly feasable to ride with a perfect crosswind.
Anything over a 20 degree angle of incidence is quite extreme... <10 degrees is normal.

About the "perfect crosswind"... in order to ever see that, the wind must be blowing faster than I am riding. If I'm riding at 25 mph what sort of wind would I need to get a perfect relative crosswind on myself? Draw the vector diagram, and you'll realize that you need a large tailwind to compensate for the forward speed. With wind coming at a 45 degree angle from the rear you'd need a 35+mph wind at wheel level to achieve a perfect crosswind... which is equivalent to ~70 mph wind as reported by airports! I never ride when it is that windy...

Now take an average breeze of 8 mph (at the airport) and say you are riding perpendicular to it. What is the angle of incidence if I'm riding at 25mph? At wheel level the wind speed will be about half what the airport gives, provided that you are riding in an open area (otherwise it will be even less)... so atan(4/25) = 9 degrees.

So... if it is really windy (18+mph) and it is a straight crosswind you could see a 20 degree angle... but most of the time it will be a lot less than that. And I'm pretty sure that a CX-ray would not have any strange flow separation issues at angles <20 degrees... you might even get a little lift effect.

If you'd like to get more complicated you could note that most of the spoke drag occurs on the top spokes which are traveling up to twice as fast as the bicycle... and on these the angle of incidence would be even less.

The oval shape will have a Cd of ~.6 at typical spoke Re number (10^3) compared to the round spoke with a Cd of 1. Multiply that by the width (.9mm and 1.5mm) and the CX-ray has only 36% of the drag that the Laser has.

From all the aero wheel tests I've seen too, it sure looks like the oval spokes are better... and that includes high angles of incidence. If Reynolds has some evidence that round is the way to go, they ought to publish it.
 

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Reynolds Stratus + spoke breakage

dawgcatching said:
I just checked the Reynolds website (I was told they were 38mm) but in fact, they are 46mm. This sounds like a poor-man's Bora! Probably exactly what I would want for an all-around wheel. Plus the sponsorship price is only $200 more than a set of Eurus! Any disagreement?

My current thinking is that I keep the Neutrons for training and windy races, sell my Eurus, and get the Reynolds for non-windy races and the TT's. The new Eurus don't seem to be any more aero than the Neutron, and about the same weight. Plus, the ride is harsher. The old Eurus were more of a departure from the Neutron-I wonder why they changed design?
Be aware that the Reynolds Stratus from 2004/2005 have a chronic spoke breakage problem. A local continental pro team was sponsored by Reynolds last year and they were using the DV and DV-UL wheelsets. They had a LOT of problems with broken spokes and eventually had all of the wheels rebuilt with heavier DT Comp 2.0/1.8/2.0 spokes. They lasted longer but eventually more spoke breakage occurred. There might be a problem with the alignment of the spoke and internal nipple that is contributing to this. Rumors last fall had Reynolds looking to change the nipple/rim interface but I can't say if this actually happened.

The Velomax Tempest Carbons seem pretty bomber, plus they are more aerodynamic than the Reynolds.
 

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rruff said:
Anything over a 20 degree angle of incidence is quite extreme... <10 degrees is normal.

About the "perfect crosswind"... in order to ever see that, the wind must be blowing faster than I am riding. If I'm riding at 25 mph what sort of wind would I need to get a perfect relative crosswind on myself? Draw the vector diagram, and you'll realize that you need a large tailwind to compensate for the forward speed. With wind coming at a 45 degree angle from the rear you'd need a 35+mph wind at wheel level to achieve a perfect crosswind... which is equivalent to ~70 mph wind as reported by airports! I never ride when it is that windy...

Now take an average breeze of 8 mph (at the airport) and say you are riding perpendicular to it. What is the angle of incidence if I'm riding at 25mph? At wheel level the wind speed will be about half what the airport gives, provided that you are riding in an open area (otherwise it will be even less)... so atan(4/25) = 9 degrees.

So... if it is really windy (18+mph) and it is a straight crosswind you could see a 20 degree angle... but most of the time it will be a lot less than that. And I'm pretty sure that a CX-ray would not have any strange flow separation issues at angles <20 degrees... you might even get a little lift effect.

If you'd like to get more complicated you could note that most of the spoke drag occurs on the top spokes which are traveling up to twice as fast as the bicycle... and on these the angle of incidence would be even less.

The oval shape will have a Cd of ~.6 at typical spoke Re number (10^3) compared to the round spoke with a Cd of 1. Multiply that by the width (.9mm and 1.5mm) and the CX-ray has only 36% of the drag that the Laser has.

From all the aero wheel tests I've seen too, it sure looks like the oval spokes are better... and that includes high angles of incidence. If Reynolds has some evidence that round is the way to go, they ought to publish it.
It wasn't a Reynolds pub. I read. Dammit, I don't write down the name of everything I read......maybe I should start.
 

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Eric_H said:
Be aware that the Reynolds Stratus from 2004/2005 have a chronic spoke breakage problem.
Which spokes were they using and where did they break? You seem to imply that they broke at the nipples. Seems like it would be tough to get the alignment screwed up since they are designed to be laced a certain way... regular rims must accomodate all sorts of lacing patterns.
 
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