Flanged vs. flangeless hubs?

psycholist

I recently got a set of custom wheels built up with the new American Classic
hubs. The rear hub is "high flange" which, I gather, is a bit of a
throw-back to an older way of doing things. Seemed to make sense to me in
that you shorten the spokes and maybe you can increase the tension or
something.

So last night I was looking at an ad for the new Bontrager Race Lite wheels
and they're promoting their new "flangeless" hubs. So what would be the
benefit of that? IIRC, they just say something fluffy like "sleeker and
more aerodynamic." OK, they look nice, but so what?

So can anyone give me a Readers Digest on the pros and cons of high flange
vs. flangeless?

Bob C.

daveornee

Psycholist wrote:
> I recently got a set of custom wheels built up with the new American
> Classic hubs. The rear hub is "high flange" which, I gather, is a bit of
> a throw-back to an older way of doing things. Seemed to make sense to me
> in that you shorten the spokes and maybe you can increase the tension or
> something.
> So last night I was looking at an ad for the new Bontrager Race Lite
> wheels and they're promoting their new "flangeless" hubs. So what would
> be the benefit of that? IIRC, they just say something fluffy like
> "sleeker and more aerodynamic." OK, they look nice, but so what?
> So can anyone give me a Readers Digest on the pros and cons of
> high flange
> vs. flangeless?
> Bob C.



The larger the flange the more distance between spoke holes, if you keep
the number of spoke holes constant. You need space between the holes to
support the load. If you use aluminum alloy hubs the space between the
spoke hoes should be at least half again as wide as the spoke hole
diameter. The aluminum alloy is usually 1/4 the strength of quality
stainless spokes. The thickness of the flange at the spoke holes is
about twice the thickness of the spoke material. This covers the minimum
safety margins of material strength. The larger the hub flange the more
torsional stifness and lateral stiffness in the wheel (all other things
held constant). The result of a larger hub flange diameter is less spoke
stretch due to torsional loads. Most single riders don't need that
additional features of torsional and lateral stiffness, but it can help
in tandems and could extend fatigue life. The quality of the build makes
a difference because there will be differences in spoke support angles
and the spoke alignment at the nipple/rim interface is different from
small to large hub flange configurations. I will let other posters
handle the stories of flangeless hubs.



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Andrew Webster

"psycholist" <technico@wctel.net> wrote in message news:<c4rl2l$4avq$1@news3.infoave.net>...
<cut>
> So can anyone give me a Readers Digest on the pros and cons of high flange
> vs. flangeless?
>
> Bob C.

To summarise Jobst Brandt's section on High vs Low in the bicycle
wheel, high flanges give additional stiffness, but low flange hubs
give more than enough stiffness anyway.

High flange wheels are (a little bit) easier to lace (than low
flange), as the spokes are further apart at the flange, this is
particularly true for high spoke counts where the requisite number of
holes would be difficult to fit round a low flange - looking at my 48
spoke wheels high flange wheels I don't think this would be possible
with a low flange design.

Flangeless designs simply make it easier to replace spokes
(particularly drive side spokes, without removing sprockets) as they
can be fitted into place in the hub along their final alignment
without bending.

Andrew Webster

Jay Hill

daveornee wrote:
> Psycholist wrote:
> > I recently got a set of custom wheels built up with the new American
> > Classic hubs. The rear hub is "high flange" which, I gather, is a bit of
> > a throw-back to an older way of doing things. Seemed to make sense to me
> > in that you shorten the spokes and maybe you can increase the tension or
> > something.

> held constant). The result of a larger hub flange diameter is less spoke
> stretch due to torsional loads. Most single riders don't need that
> additional features of torsional and lateral stiffness, but it can help
> in tandems and could extend fatigue life.

That's why you also still see them on track bikes, justifiably or not.

dianne_1234

On Mon, 5 Apr 2004 08:56:50 -0400, "psycholist" <technico@wctel.net>
wrote:

>I recently got a set of custom wheels built up with the new American Classic
>hubs. The rear hub is "high flange" which, I gather, is a bit of a
>throw-back to an older way of doing things. Seemed to make sense to me in
>that you shorten the spokes and maybe you can increase the tension or
>something.
>
>So last night I was looking at an ad for the new Bontrager Race Lite wheels
>and they're promoting their new "flangeless" hubs. So what would be the
>benefit of that? IIRC, they just say something fluffy like "sleeker and
>more aerodynamic." OK, they look nice, but so what?
>
>So can anyone give me a Readers Digest on the pros and cons of high flange
>vs. flangeless?
>
>Bob C.
>

Would getting rid of the flange save weight?

Andrew Webster

dianne_1234 <dianne_1234@NOSPAMyahoo.com> wrote in message news:<me84705qrdfnise9oqu86i3vv59kbrggb0@4ax.com>...
> On Mon, 5 Apr 2004 08:56:50 -0400, "psycholist" <technico@wctel.net>
> wrote:
>
<cut>
>
> Would getting rid of the flange save weight?


Not necessarily. Indeed Shimano Deore flangeless (Shimano
FH-M555-S/L) weighs in at 485g compared with the Deore flanged version
(Shimano FH-M525-S/L) at 449g. Weights taken from
www.shimano-europe.com.

(the really weight conscious must also allow for the longer spokes
required to reach the spoke sockets of the flangeless hub).

I can't really see any compelling reason for going for a flangeless
design - perhaps others could suggest one? The only advantage seems to
be ease of spoke replacment.

Andrew Webster

scituatejohn

Andrew Webster wrote:
> I can't really see any compelling reason for going for a flangeless
> design - perhaps others could suggest one? The only advantage seems to
> be ease of spoke replacment.


You don't have to bend the spoke, and a bent section would be weaker
than a straight section of the same size. I don't know how frequently
spokes break at the bend, so this may or may not be an issue of consern.



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