I read the tech paper re:spokes on the Zipp website and it looks like there is some considerable benefit in using ovalized spokes (like Sapim cx-ray or DT aerolite) over regular 14g round spokes. Something like 10-15 watts per wheel just to spin it plus aero-drag. Has anyone checked this out or done it? I have a 30mm rim with 20 14g round spokes. Would rebuilding with oval spokes gain that much?
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Re: Faster Wheels with Oval Spokes [chris_gr]
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Back in the days before production aero wheels, I built a pair of my own. I used Alpina Oval 14g spokes. I felt faster on them, but I really don't know how much benefit they provided.
Re: Faster Wheels with Oval Spokes [chris_gr]
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It may make a difference at 30Mph, but unless you are holding 30MPH right now, I wouldn't bother. Deeper rims will make a much bigger difference.
Re: Faster Wheels with Oval Spokes [JohnA]
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Re: Faster Wheels with Oval Spokes [JohnA]
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Serious question: If the spokes save 15 watts at 30 mph, how many watts do they save at 20 mph?
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"People think it must be fun to be a super genius, but they don't realize how hard it is to put up with all the idiots in the world."
Re: Faster Wheels with Oval Spokes [vitus979]
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without doing any real math I want to say about 2-4 watts at 20mph...that's my best guess
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Re: Faster Wheels with Oval Spokes [vitus979]
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4.4 watts
Re: Faster Wheels with Oval Spokes [vitus979]
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Re: Faster Wheels with Oval Spokes [chris_gr]
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I just returned, a few hours ago from a day of testing at the A&M wind tunnel. We tested bars, wheels, riders etc. I suspect that in wheel testing with oval vs. round butted spokes that spoke count will be a bigger factor. When ther are more than 24 spokes, I've found that bladed spokes start to matter. At 16 or 18 on the front, 14/17 round and 14 ovals are soooo close. Rim depth is a much bigger deal, tire to rim match up also is some important. If you average 19mph or less I would not hesitate to use round spokes.
Re: Faster Wheels with Oval Spokes [vitus979]
[ In reply to ]
[reply]Serious question: If the spokes save 15 watts at 30 mph, how many watts do they save at 20 mph?[/reply]
Riding 22mph into a 10mph sidewind = equivalent of a 24mph headwind at 22.6 degrees. Riding the GFT last year with a 20mph sidewind at 20mph = 28mph at 45 degrees. Very rarely do I ride in dead calm or without significant crosswind.
That said, bladed spokes are dumb in crosswinds but oval spokes are a slight improvement, maybe. Using less spokes is more important than the shape of the spokes. Based on the numbers I remember seeing, 15 watts is too high...but it's late and I am tired. What I do know for certain is the oval spokes on my Hed 60 whistle in the air, and the round ones on my Spinergy Tilium do not. Unless they are perfectly aligned then they will cause more drag, and in a crosswind they have higher drag than an equivalent round spoke.
Riding 22mph into a 10mph sidewind = equivalent of a 24mph headwind at 22.6 degrees. Riding the GFT last year with a 20mph sidewind at 20mph = 28mph at 45 degrees. Very rarely do I ride in dead calm or without significant crosswind.
That said, bladed spokes are dumb in crosswinds but oval spokes are a slight improvement, maybe. Using less spokes is more important than the shape of the spokes. Based on the numbers I remember seeing, 15 watts is too high...but it's late and I am tired. What I do know for certain is the oval spokes on my Hed 60 whistle in the air, and the round ones on my Spinergy Tilium do not. Unless they are perfectly aligned then they will cause more drag, and in a crosswind they have higher drag than an equivalent round spoke.
Re: Faster Wheels with Oval Spokes [John Cobb]
[ In reply to ]
Thanks John,
I discovered on the weekend that my old-school 32 3x spoke wheels are the best choice when crashing at 40kph. broke two spokes and got 6 stitches when my knee went into the front wheel. Cannot imagine what a mess it would have been if it was a 16 spoke radial bladed set up. Then again maybe I should pay closer attention when putting my water bottle back in the cage.
I discovered on the weekend that my old-school 32 3x spoke wheels are the best choice when crashing at 40kph. broke two spokes and got 6 stitches when my knee went into the front wheel. Cannot imagine what a mess it would have been if it was a 16 spoke radial bladed set up. Then again maybe I should pay closer attention when putting my water bottle back in the cage.
Re: Faster Wheels with Oval Spokes [John Cobb]
[ In reply to ]
John,
What affects tire to rim match up and how can one ensure it's optimum?
What affects tire to rim match up and how can one ensure it's optimum?
Re: Faster Wheels with Oval Spokes [dgunthert]
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Re: Faster Wheels with Oval Spokes [triguy42]
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I've got a set of Bontrager Race X-Lites on a Trek 5500. I have a set of Alps on a Cervelo Soloist. Undoubtedly, the Trek is the faster bike. I haven't ridden the Bontragers on the Cervelo, but I've ridden the Alps on the Trek. The Bontrager wheels are definately faster in combination.
I have a Trek TT bike with 650 Bontrager Race Aero wheels. When I take the Bontragers off and use the HED Alps front and Renn disc on the back, I gain practically nothing (and feel like I lose handling confidence and comfort).
I'm coming to the conclusion that the paired spoke thing really works to reduce drag and that the Bontrager wheels are pretty awesome. Anyone else have similar experience/conclusions?
Bob C.
I have a Trek TT bike with 650 Bontrager Race Aero wheels. When I take the Bontragers off and use the HED Alps front and Renn disc on the back, I gain practically nothing (and feel like I lose handling confidence and comfort).
I'm coming to the conclusion that the paired spoke thing really works to reduce drag and that the Bontrager wheels are pretty awesome. Anyone else have similar experience/conclusions?
Bob C.
Re: Faster Wheels with Oval Spokes [psycholist]
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Re: Faster Wheels with Oval Spokes [Sojourner]
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You know that is very interesting I am sure you are familiar with the little hill going in the east entrance at Bonelli park, long story short, only now with a set of 606's have I gone as fast as nearly three years ago on a set of Rolf Vector Pro's. No matter what set up including disk/tri-spoke was within 2mph. Certainly not scientific, but you notice things like this when you go down a hill 10+ times a week over a period of years.
Re: Faster Wheels with Oval Spokes [Race4LV]
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Re: Faster Wheels with Oval Spokes [Sojourner]
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The Vector pro's are not made anymore due to the split between Rolf and Trek. The Vector pro's were the top of the line at the time. I am sure there are refinements and such over the years but I believe the Vigors are roughly the equivalent to the Vector pro wheels. I put roughly 2500 miles on the Vector pro wheels before I turned them over to my wife, I never even needed to true them. I would venture to say the Vigor wheels are top notch as well. If I was shopping for a wheel in that category they would be at or near the top of the list.
Attributes: semi aero, light weight, durable aluminum clincher rim, high quality hubs, paired spokes
Attributes: semi aero, light weight, durable aluminum clincher rim, high quality hubs, paired spokes
Re: Faster Wheels with Oval Spokes [Race4LV]
[ In reply to ]
Michael Hutchinson, winner of the 10, 25, 50, 100 mile and 12 hour TT championships in the UK this year, always rides a Vector Pro on the front in the big races.
Re: Faster Wheels with Oval Spokes [Sojourner]
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"I had a set of the Rolf Vigors. They only have a 34mm rim depth, I think, but I havn't been on any wheelset that felt nearly as fast. I'd like to pick up another set. "
I'm curious, why did you get rid of them if they felt so fast?
I'm curious, why did you get rid of them if they felt so fast?