wheelbuilding question(s)-rim sources?



the blur

New Member
Apr 15, 2004
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hi-
i'm looking to build up a set of fast 700c road wheels (aero) that i'll use every day in fast group rides. i think i'll use aero bladed spokes like DT aerolights or sapim cx- ray. i can find hubs with 20/24 drilling (front/rear) but where do i find some aero rims that are drilled that way? all i can find are mavic cxp33's with 28 holes. any suggestions for sources, or other rims to recommend? how about non-proprietary paired spoke rims? also, any opinions on bearing drag for different hubsets? i'm looking at some american classic hubs. opinions? how about white industries? thanks for opinions
(trying not to spend $800 for rolf prima vigors)

extra questions: the concept of an aero wheel-is it low spoke counts/bladed spokes that make the difference, or the deep rim-or both? are the rims deep and stiff so you can use less spokes, or is the deep rim important in a slipstream/turbulence decreasing effect? or is the main effect low spoke number?
why is there no data on wheel efficiency? taking into account bearing seal drag, wind efficiency, weight distribution (hub vs rim) etc. has anyone taken different wheels and just "rolled them down an incline" and tabulated that?
 
"the blur" <[email protected]> wrote
in message news:[email protected]...
>
> hi-
> i'm looking to build up a set of fast 700c road wheels (aero)

that i'll
> use every day in fast group rides. i think i'll use aero

bladed spokes
> like DT aerolights or sapim cx- ray. i can find hubs with

20/24
> drilling (front/rear) but where do i find some aero rims that

are
> drilled that way? all i can find are mavic cxp33's with 28

holes. any
> suggestions for sources, or other rims to recommend? how about
> non-proprietary paired spoke rims? also, any opinions on

bearing drag
> for different hubsets? i'm looking at some american classic

hubs.
> opinions? how about white industries? thanks for opinions
> (trying not to spend $800 for rolf prima vigors)
>
> extra questions: the concept of an aero wheel-is it low spoke
> counts/bladed spokes that make the difference, or the deep

rim-or both?
> are the rims deep and stiff so you can use less spokes, or is

the deep
> rim important in a slipstream/turbulence decreasing effect? or

is the
> main effect low spoke number?
> why is there no data on wheel efficiency? taking into account

bearing
> seal drag, wind efficiency, weight distribution (hub vs rim)

etc. has
> anyone taken different wheels and just "rolled them down an

incline"
> and tabulated that?
>
>
> --
> the blur


Dear Mr. The Blur,

Putting aside for the moment the prudence of a 20/24 spoke wheel,
one choice is the Velocity Deep V.
http://velocityusa.com/rims/road-rims.php . If I were building a
semi-aero, ultra-light wheel with bladed spokes, however, I would
use an Aerohead OC 28 hole rim for the rear. By the way, there
is plent of data bearing on your questions, which Carl Fogel will
undoubtedly dredge up from the bowels of the internet. -- Jay
Beattie.
 
the blur wrote:
> hi-
> i'm looking to build up a set of fast 700c road wheels (aero)

---8<--
> i can find hubs with 20/24
> drilling (front/rear) but where do i find some aero rims that are
> drilled that way?

---8<---

Just answering the bit above, try www.corima.fr for some fine carbon
rims in a number of drillings. You might want to confirm what spokes
you have to use, before buying. /Robert
 
On Wed, 8 Jun 2005 10:15:11 -0700, "Jay Beattie"
<[email protected]> wrote:

>
>"the blur" <[email protected]> wrote
>in message news:[email protected]...
>>
>> hi-
>> i'm looking to build up a set of fast 700c road wheels (aero)

>that i'll
>> use every day in fast group rides. i think i'll use aero

>bladed spokes
>> like DT aerolights or sapim cx- ray. i can find hubs with

>20/24
>> drilling (front/rear) but where do i find some aero rims that

>are
>> drilled that way? all i can find are mavic cxp33's with 28

>holes. any
>> suggestions for sources, or other rims to recommend? how about
>> non-proprietary paired spoke rims? also, any opinions on

>bearing drag
>> for different hubsets? i'm looking at some american classic

>hubs.
>> opinions? how about white industries? thanks for opinions
>> (trying not to spend $800 for rolf prima vigors)
>>
>> extra questions: the concept of an aero wheel-is it low spoke
>> counts/bladed spokes that make the difference, or the deep

>rim-or both?
>> are the rims deep and stiff so you can use less spokes, or is

>the deep
>> rim important in a slipstream/turbulence decreasing effect? or

>is the
>> main effect low spoke number?
>> why is there no data on wheel efficiency? taking into account

>bearing
>> seal drag, wind efficiency, weight distribution (hub vs rim)

>etc. has
>> anyone taken different wheels and just "rolled them down an

>incline"
>> and tabulated that?
>>
>>
>> --
>> the blur

>
>Dear Mr. The Blur,
>
>Putting aside for the moment the prudence of a 20/24 spoke wheel,
>one choice is the Velocity Deep V.
>http://velocityusa.com/rims/road-rims.php . If I were building a
>semi-aero, ultra-light wheel with bladed spokes, however, I would
>use an Aerohead OC 28 hole rim for the rear. By the way, there
>is plent of data bearing on your questions, which Carl Fogel will
>undoubtedly dredge up from the bowels of the internet. -- Jay
>Beattie.


Dear Jay,

[Bullfrog sees red flannel waving, bullfrog's tongue lashes
out.]

http://damonrinard.com/aero/aerodynamics.htm

The link above to an article by Rainer Pivit has a nice
table of potential aerodynamic improvements due to taping
shoelaces, shaving legs, and so forth.

It indicates that switching to one particular front aero-rim
might save 44 seconds in a 65-minute 40km ride, while a
similar rear aero-rim might save another 18 seconds.

Such small improvements are probably visible only in
predictions, not in averaged test runs, since the wind (and
the rider's breakfast) will normally cause more variation
than 1 minute out of 65 on an outdoor ride:

Out of curiosity, I put 37 km/h for a 65-minute 40 km ride
into this calculator, using a default rider on a triathlon
bike:

http://www.kreuzotter.de/english/espeed.htm

With no wind, the prediction is 213 watts, 64:51.9.

With a 1 mph headwind, the same 213 watts takes 65:56.0.

That's about 63 seconds longer--roughly the 66 seconds that
the other page predicts might be saved by an aero rim.

Carl Fogel