Calendar
Retailers
Stack & Reach
Custom Geometry Calculator
Online Training Log
MAIN
INDEX
RULES &
LEGEND
LOG
IN
Search
this forum
this category
all forums
for
All words
Any words
Whole Phrase
(
options
)
Newsletter Signup
Slowtwitch Forums
:
Triathlon Forum
:
New wheel concept
1
2
3
View All
Tri Forum
Classifieds
Lavender Room
Jobs
The Womens
Print Thread
bikinpolitico
Aug 27, 08 22:10
Post #26 of 71 (1042 views)
Re: New wheel concept [GregX]
[
In reply to
]
Can't Post
In Reply To
if this wheel is truly aero and you wanted to save some money in the initial testing, you could probably do some very good testing with a known closed course, a consistent rider, an accurate powermeter, and some good data analysis.
You could save even more money by making it look aero and making wild claims to its aeroness. Works for the big guys, right?
http://AustinBikeBlog.org
Your one-stop resource with everything you need to know to use a bicycle for your everyday life.
(This post was
edited
by bikinpolitico on Aug 27, 08 22:10)
steve lubanski
Aug 27, 08 22:28
Post #27 of 71 (1027 views)
Re: New wheel concept [GregX]
[
In reply to
]
Can't Post
I am not to sure about that. If you look at a four bladed carbon wheel, there are only four contact points to the rim{albeit larger}. A lot of the weight in those wheels are in the blades, because they must hinder both up and down forces, and lateral forces. I have tried to get by that by giving the lateral forces to different members, i.e. the cables.
Steve SMp
GregX
Aug 28, 08 8:09
Post #28 of 71 (938 views)
Re: New wheel concept [steve lubanski]
[
In reply to
]
Can't Post
i am not "sure" either, but being an experienced wheel builder of conventional spoked wheels, i know how very subtle spoke tension changes very quickly affect a wheel's trueness and roundness.
and just looking at the way your wheel is arranged, it seems that you will have "flat" spots (we're talking 'relative' flat spots) on your wheel's rim at the 4 points where the tensioning cables connect.
in any case, it would very interesting to see a photo of the real thing, the real wheel. cool idea though ...
"Half of what we taught you is wrong. Unfortunately, we do not know which half."
-- Dean and cardiologist C. S. Burwell to a Harvard Med School graduating class.
Where would
you
want to swim ?
paul@hellovelo
Aug 28, 08 8:28
Post #29 of 71 (911 views)
Re: New wheel concept [steve lubanski]
[
In reply to
]
Can't Post
He manages to spend a lot of time in wind tunnels (no that wasn't a setup for a joke), that was all.
Good luck with this.
p.
------------------------
Padyak Pinoy in 2009?
hellovelo.ca
Tom A.
Aug 28, 08 8:31
Post #30 of 71 (905 views)
Re: New wheel concept [steve lubanski]
[
In reply to
]
Can't Post
In Reply To
I am not saying it is a training wheel. Take any full carbon rim, hit a nice pothole, and then tell me how it held up. By the way, this first edition weighs in at 620 grams.
Steve Smp
Steve,
I'm with GregX on this one...I think to pull this off, you're going to need a pretty stiff rim section, both in the plane of the wheel and transverse to it. Now, a relatively deep carbon rim will get you there (deeper than what you've shown IMO) and will enhance the aerodynamics, but it's going to end up heavier than what you've estimated so far.
Also, have you estimated the drag of the tubular "compression" spokes vs. a good bladed spoke like a CX-ray or something? If it's only 2X the drag (very possible with a relatively large diameter tube like that) then your "total spoke drag" is going to be the equivalent of a conventional 16 spoke wheel. Lots of those out there already.
I'm not trying to be a naysayer in all this...I'm just trying to make sure you've thought everything through on this. The bicycle wheel has had over 100 years of development, and many things have been tried over the years. There's a reason that most wheels are pretty similar in construction.
Hope that helps,
Tom
GregX
Aug 28, 08 8:50
Post #31 of 71 (870 views)
Re: New wheel concept [Tom A.]
[
In reply to
]
Can't Post
looking at the wheel a bit more and thinking about the likely forces within it, i wonder if during riding the 4 thicker members that are
supposed
to be under compression are
actually
under tension. because then the wheel might actually stay fairly round.
but, of course, if this is the case, the 4 thick members could easily be replaced by cables or spokes and the wheel would likely end up lighter and more aerodynamic ...
"Half of what we taught you is wrong. Unfortunately, we do not know which half."
-- Dean and cardiologist C. S. Burwell to a Harvard Med School graduating class.
Where would
you
want to swim ?
Tom A.
Aug 28, 08 9:05
Post #32 of 71 (844 views)
Re: New wheel concept [GregX]
[
In reply to
]
Can't Post
In Reply To
looking at the wheel a bit more and thinking about the likely forces within it, i wonder if during riding the 4 thicker members that are
supposed
to be under compression are
actually
under tension. because then the wheel might actually stay fairly round.
but, of course, if this is the case, the 4 thick members could easily be replaced by cables or spokes and the wheel would likely end up lighter and more aerodynamic ...
How would they be under tension? If you look at each quarter arc section of the wheel, you'll have the tension wires "pulling in" on either end of the arc, with the "post" of the tubular spoke being put into compression.
If the rim isn't stiff enough, this wheel is going to end up pretty darn "square" shaped...squares don't roll too well ;-)
Steve, have you done any analysis on this wheel concept yet? I pretty simple FEM model would reveal a LOT.
steve lubanski
Aug 28, 08 21:48
Post #33 of 71 (733 views)
Re: New wheel concept [GregX]
[
In reply to
]
Can't Post
So far 500 miles on one wheel with no deformation, used by a cat 2 6' 1" lbs.
Steve SMp
steve lubanski
Aug 28, 08 21:55
Post #34 of 71 (729 views)
Re: New wheel concept [Tom A.]
[
In reply to
]
Can't Post
Throuhout the whole process of any of my designs, wheel, pedal, stem, crank, saddle, helmet. people have always asked me why if this idea is so good, that nobody had thought of it before. The answer is two fold, First, these ideas, ie. my pedal have been around for a hundred years. My luck was to be born in a time that had technology make these ideas work.. The second is more of a story. When I used to go to the bank with my mom back in the sixties, you would try to line up in the shortest line. Then boom, one day someone thought of a master line. Wow why didn't somebody think of that before.
Steve SMp
steve lubanski
Aug 28, 08 22:02
Post #35 of 71 (721 views)
Re: New wheel concept [Tom A.]
[
In reply to
]
Can't Post
You know what is even better than a FEA of the wheel is taking it out and putting some serious hurt on it. I have ridden hundreds of wheels over the last 30 years, and with the exception of a full front disc, this seems to be one of the fastest wheels I have ever ridden. For the last eight years I have been riding prototypes of the four bladed carbon Stella Azura wheels, and have close to 60,000 miles on them. They are very fast but are truly a handfull in side winds. Yesterday I took out my wheel in a pretty good wind and could take my hands off the bars. That means a lot to me.
Steve SMp
Tom A.
Aug 28, 08 22:21
Post #36 of 71 (709 views)
Re: New wheel concept [steve lubanski]
[
In reply to
]
Can't Post
In Reply To
You know what is even better than a FEA of the wheel is taking it out and putting some serious hurt on it. I have ridden hundreds of wheels over the last 30 years, and with the exception of a full front disc, this seems to be one of the fastest wheels I have ever ridden. For the last eight years I have been riding prototypes of the four bladed carbon Stella Azura wheels, and have close to 60,000 miles on them. They are very fast but are truly a handfull in side winds. Yesterday I took out my wheel in a pretty good wind and could take my hands off the bars. That means a lot to me.
Steve SMp
Do you happen to have a power meter?
edit: Oh yeah...why did you post a pic of a CAD model of the wheel instead of the real thing? Just curious...
(This post was
edited
by Tom A. on Aug 28, 08 22:23)
steve lubanski
Aug 28, 08 22:22
Post #37 of 71 (706 views)
Re: New wheel concept [Tom A.]
[
In reply to
]
Can't Post
The tubular compression spokes come from the center of the hub and are therfore hidden by the rim, making them very very aero
Steve SMp
Tom A.
Aug 28, 08 22:25
Post #38 of 71 (702 views)
Re: New wheel concept [steve lubanski]
[
In reply to
]
Can't Post
In Reply To
The tubular compression spokes come from the center of the hub and are therfore hidden by the rim, making them very very aero
Steve SMp
Only when the apparent wind is exactly straight ahead...
steve lubanski
Aug 28, 08 22:27
Post #39 of 71 (700 views)
Re: New wheel concept [Tom A.]
[
In reply to
]
Can't Post
Remember all compression spokes do a pretty good job at tension. but tension spokes do little or no work in compression. You could and I did ride this wheel down a straight rode and not turn or lean the bike in any way, in other words. coast, and the wheel would hold up. The compression spokes do the majority of the work and the tension ones are there only for lateral support.
Steve SMp
steve lubanski
Aug 28, 08 22:29
Post #40 of 71 (699 views)
Re: New wheel concept [Tom A.]
[
In reply to
]
Can't Post
And like I said earlier, in a strong side wind I am able to take my hands off the bar. Try that with a normal aero wheel.
Steve SMp
steve lubanski
Aug 28, 08 22:35
Post #41 of 71 (693 views)
Re: New wheel concept [Tom A.]
[
In reply to
]
Can't Post
The reason why I put up a cad model of the wheel is that I am so non computer literate that I had to get my wife to put up the picture for me. I Dont even have a computer at my bike shop. Dont have the time. One man 12,000 sq ft. That is why my posts are always at night when I finally get home. By the way I do have an appt in mid Dec. at the wind tunnel in San Diego
Steve SMp
quellish
Aug 28, 08 22:38
Post #42 of 71 (690 views)
Re: New wheel concept [steve lubanski]
[
In reply to
]
Can't Post
In Reply To
I have developed a new wheel design which uses four spokes and eight cables. I beleive it is very aero especially in dealing with side winds. My question to anybody is who, or which wind tunnel would be the best to test a wheel design at different yaw angles.
Steve
SMp
I would say take it over to Rich at Wheelbuilder. If you can get him to buy into the concept, that's a major feather in your cap (and he's close). At the very least he can probably recommend people who could help with aero and structural testing.
"Motivation is the key to success in whatever you're doing in life. It comes a lot easier when you're doing something you love and have passion for. My goal is to have a good time and a hot run. And I'm not afraid of disappointment - it only makes me work harder."
--Missy Giove
steve lubanski
Aug 28, 08 22:46
Post #43 of 71 (688 views)
Re: New wheel concept [quellish]
[
In reply to
]
Can't Post
Thank you for the suggestion.
Steve SMp
Tom A.
Aug 28, 08 23:47
Post #44 of 71 (671 views)
Re: New wheel concept [steve lubanski]
[
In reply to
]
Can't Post
In Reply To
Remember all compression spokes do a pretty good job at tension. but tension spokes do little or no work in compression. You could and I did ride this wheel down a straight rode and not turn or lean the bike in any way, in other words. coast, and the wheel would hold up. The compression spokes do the majority of the work and the tension ones are there only for lateral support.
Steve SMp
Hmmm...I think you might want to review the concept of a prestressed structure. Believe it or not, just like in a regular wheel, the spokes in tension DO support part of the load.
Tom A.
Aug 28, 08 23:51
Post #45 of 71 (668 views)
Re: New wheel concept [steve lubanski]
[
In reply to
]
Can't Post
In Reply To
And like I said earlier, in a strong side wind I am able to take my hands off the bar. Try that with a normal aero wheel.
Steve SMp
So...I can do that with my 16 spoke Performance Titan front wheel. It weighs 750 grams and was part of a wheelset I only paid ~$120 for new. Show me data from a simple field test with a power meter that your wheel concept is lower drag. Call me a naysayer if you like, but I'm not betting it will be.
steve lubanski
Aug 29, 08 7:24
Post #46 of 71 (598 views)
Re: New wheel concept [Tom A.]
[
In reply to
]
Can't Post
A test with a powermeter may satisfy you, but not everyone. I will wait untill Dec when I take the wheel down to San Diego and have it independtly tested by the experts. Also I did not say that tension spokes do nothing. but there compression stength cannot even be compared to a true compression spoke.
Steve
SMp
DuGuy
Aug 29, 08 7:49
Post #47 of 71 (574 views)
Re: New wheel concept [steve lubanski]
[
In reply to
]
Can't Post
Man, I was disappointed. I thought it would be something awesome like this!
http://www.vimeo.com/...mbed&sec=1021081
Good work! Glad to see people challenging the mainstream. Don't worry about the negative nancys on here...they're just hella jealous ;)
"I consider myself blinding fast. I am like a gazelle on methamphetamines that has been shocked by a taser. That fast." - unclerico
paul_tx
Aug 29, 08 8:01
Post #48 of 71 (559 views)
Re: New wheel concept [steve lubanski]
[
In reply to
]
Can't Post
Here's a link to Texas A&M's low speed wind tunnel.
http://lswt.tamu.edu/
out
Aug 29, 08 8:10
Post #49 of 71 (542 views)
Re: New wheel concept [steve lubanski]
[
In reply to
]
Can't Post
Good choice of testing facility.
May I make the following suggestions:
1. Test your wheel first, with a variety of tires to find out what works best.
2. Test your competitors wheels with the same tire that you find works best on your wheel.
3. Test your competitors wheels with the manufacturers recommended tire. (i.e. Hed 3 - Bontrager aerowing, Zipp - Tangente, etc.)
4. Yaw both ways.
5. Try testing in a fork or two
6. Should you bring the wheel to the market, show people the unaltered data straight from the horses mouth.
Best of luck. I am curious about the spoke width, rim width, hub size and a lot of the specifics. It seems you are shooting for the "narrow" wheel from days of old, whereas the current market trend among Zipp and Hed is to make things wide. I think there is a reason to believe in the low FA scheme but it always begs the question, what tire should I run, and how much is the rolling resistance costing me?
Tom A.
Aug 29, 08 8:35
Post #50 of 71 (514 views)
Re: New wheel concept [steve lubanski]
[
In reply to
]
Can't Post
In Reply To
A test with a powermeter may satisfy you, but not everyone. I will wait untill Dec when I take the wheel down to San Diego and have it independtly tested by the experts.
Oh c'mon Steve, that's a copout. A simple test with a powermeter would tell YOU if what you're doing is worth pursuing BEFORE you potentially waste money on it testing it out in a wind tunnel. But hey, it's your money...
I can't believe you're not going to try to quantify any gains BEFORE going into the tunnel? Especially since it would be so easy...wow...
In Reply To
Also I did not say that tension spokes do nothing.
but there compression stength cannot even be compared to a true compression spoke.
Steve
SMp
Sure they can, just so long as they don't be come detensioned. A tension spoke can handle a compressive load as long as it's less than the tensile force in it. How do you think a wheel with NO "compression members" works (i.e. the vast majority of all bicycle wheels). Like I said earlier, you might want to brush up on your knowledge of prestressed structures.
Let me give you something to ponder. Concrete as a material is excellent in compression but horrible in tension...yet, there are structures all over the place that use concrete to support a tensile load. Gee, how do they do that??
1
2
3
View All
Print Thread
The Pro Effect
Which male pro is most likely to influence your buying decisions
Al Sultan
Alexander
Andersson
DeBoom
Frodeno
Gomez
Kemper
Lieto
Lovato
McCormack
Other
Potts
Rapp
Reid
Sindballe
Stadler
Whitfield
MAIN
RULES &
LOG
