Spoke Question (butted vs. straight gauge)



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Terry Morse writes:

>> Maybe some day I can get someone to make labyrinth sealed hubs, seals like we find only on
>> Sturmey Archer gear hubs. You'll find that on disassembly these hubs are always clean inside even
>> though they are 50 years old.

> How much mileage do folks get out of Phil Wood hub bearings? I've never been inclined to try them,
> but I know some long distance riders who swear by them for wet conditions.

People swear by all sorts of things but a contact face lip seal is not reliable for that use.
Typically seals on automobiles are used to keep oil IN and are protected by a labyrinth from water.
There are two rules of seals that bicycle "sealed bearings" violate.

1. No two liquids can be reasonably separated by a single contact lip.

2. A contact lip seal that doesn't leak, leaks.

The second bears on the first. If the retained fluid does not seep under the lip, the seal lip will
go dry and burn away its preload for lack of lubrication, thereby becoming a capillary for external
water in the case of the bicycle. If there is water on one side and oil on the other, the two will
mix under the lip. Separating two fluids requires two lips with a vent between to make sure the
interstitial does not fill with one or the other fluid. Typically an automatic transmission oil on a
Corvair and its Hypoid oil required two seals.

Bicycle people do not come from a background of tribology and have no idea what that is all about. I
find it surprising that SA hubs were designed with labyrinth seals but then New Departure coaster
brakes also had such a seal. It seems there were still skilled engineers employed in the bicycle
business in the early 20th century.

The Phil Wood hub was a great disservice to bicycling when it introduced electric motor shaft
bearings with air flow seals posing as water seals. Unfortunately, the bicycle industry, not knowing
much about seals went head over heels to imitate this "great success."

Electric motors that are natural air pumps (that's how they cool themselves) use simple lip face
seals to prevent air being sucked through the shaft bearings, the natural low pressure zone, and gum
up the bearing grease with atmospheric dust. These seals were never intended to seal the bearing
against water although most people believe they can do that. This may be true for an occasional
splash, but hydrostatic water pressure will go into the bearing.

Jobst Brandt [email protected] Palo Alto CA
 
> Jobst Brandt wrote:
> > Maybe some day I can get someone to make labyrinth sealed hubs, seals like we find only on
> > Sturmey Archer gear hubs. You'll find that on disassembly these hubs are always clean inside
> > even though they are 50 years old.

"Terry Morse" <[email protected]> wrote in message
news:[email protected]...
> How much mileage do folks get out of Phil Wood hub bearings? I've never been inclined to try them,
> but I know some long distance riders who swear by them for wet conditions.

As was mentioned earlier, that class of bearing is commonly delivered with an oil rinse only. Phil
adds plenty of grease, which is good practice for cartridge bearings.

Some bicycle dealers replace hub bearing cartridges without adding lubricant. The unlubricated life
is abysmal. It's simple and quick to lift a shield, fill the bearing and reinstall the cover.
--
Andrew Muzi http://www.yellowjersey.org Open every day since 1 April 1971
 
> Terry Morse writes:
> >> Maybe some day I can get someone to make labyrinth sealed hubs, seals like we find only on
> >> Sturmey Archer gear hubs. You'll find that on disassembly these hubs are always clean inside
> >> even though they are 50 years old.
>
> > How much mileage do folks get out of Phil Wood hub bearings? I've never been inclined to try
> > them, but I know some long distance riders who swear by them for wet conditions.

<[email protected]> wrote in message news:[email protected]...
> People swear by all sorts of things but a contact face lip seal is not reliable for taht use.
> Typically seals on automobiles are used to keep oil IN and are protected by a labyrinth from
> water. There are two rules of seals that bicycle "sealed bearings" violate.
>
> 1. No two liquids can be reasonably separated by a single contact lip.
>
> 2. A contact lip seal that doesn't leak, leaks.
>
> The second bears on the first. If the retained fluid does not seep under the lip, the seal lip
> will go dry and burn away its preload for lack of lubrication, thereby becoming a capillary for
> external water in the case of the bicycle. If there is water on one side and oil on the other, the
> two will mix under the lip. Separating two fluids requires two lips with a vent between to make
> sure the interstitial does not fill with one or the other fluid. Typically an automatic
> transmission oil on a Corvair and its Hypoid oil required two seals.
>
> Bicycle people do not come from a background of tribology and have no idea what that is all about.
> I find it surprising that SA hubs were designed with labyrinth seals but then New Departure
> coaster brakes also had such a seal. It seems there were still skilled engineers employed in the
> bicycle business in the early 20th century.
>
> The Phil Wood hub was a great disservice to bicycling when it introduced electric motor shaft
> bearings with air flow seals posing as water seals. Unfortunately, the bicycle industry, not
> knowing much about seals went head over heels to imitate this "great success."
>
> Electric motors that are natural air pumps (that's how they cool themselves) use simple lip face
> seals to prevent air being sucked through the shaft bearings, the natural low pressure zone, and
> gum up the bearing grease with atmospheric dust. These seals were never intended to seal the
> bearing against water although most people believe they can do that. This may be true for an
> occasional splash, but hydrostatic water pressure will go into the bearing.

Phil does fill the bearing case with grease, which is something not all hub vendors do, and so their
reputation, _by comparison_, is better. I grant you not among bearings with shields but just among
bicycle hubs. It's all a matter of degree in available equipment and although the shield used is
not, as you exhaustively note, the best one for the application, their product just isn't as
horrible as others.

--
Andrew Muzi http://www.yellowjersey.org Open every day since 1 April 1971
 
On Mon, 03 Mar 2003 21:13:56 -0600, Tim McNamara <[email protected]> wrote:

>ISTR that the "wind tunnel testing" used by Orville and Wilbur was models mounted on the handlebars
>of their bikes.

Actually, they built a small wind-tunnel where they tested airfoils. They used balance beams to
measure lift vs. drag for various airfoil shapes at differing angles of attack.

jeverett3<AT>earthlink<DOT>net http://home.earthlink.net/~jeverett3
 
Tim McTeague <[email protected]> wrote:
> I am sooo tired of this old canard. Urban myth I say. Exactly who are these engineers? This saying
> comes up when people don't like the facts.

>> When engineers scratched their heads and said that bumblebees can't fly,
> it
>> just proved that sometimes, the guys who have actually done the job know much, much more than
>> those engineers in the ivory towers.

It was actually done as an aerodynamic analysis to answer an entomological question. The question
wasn't "Can bumblebees fly?", since they obviously can. The question was "Do bumblebees change the
shape of their wings when they fly?". This was before high speed strobe photography could answer the
question directly. The analysis proved that bumblebees with rigid wings (i.e., constant shape)
couldn't fly, so the conclusion was that they did change the shape of their wings on each stroke.

mike

--
Mike Fischbein [email protected] Any opinions expressed are mine and not necessarily those of any other
entity. They may not even be mine.
 
On Tue, 4 Mar 2003 08:34:34 -0600, "Paul Butler" <[email protected]> wrote:
>
>These Shimano hubs claim to have labyrinth seals. How are they deficient?
>
>http://tinyurl.com/6txn http://tinyurl.com/6txu
>
>[email protected]

I don't know whether Campagnolo claims the same or not, but technically they also have labyrinth
seals. The problem with their is that they're far too small i.e. the spaces between the two cups are
too small - and therefore capilary action takes place and pulls water into the bearing assembly.

It seems to me that a labyrinth seal is not something that scales down well - they have to be big
with adequate space between the seal as well as have good drainage.

Johan Bornman
 
"Qui si parla Campagnolo" <[email protected]> wrote in message
news:[email protected]...
> << What's with that? We all know the image you're trying to conjure with
that
> title. That's way out of line.
>
> There's an Italian guy i know that I call 'Capo'.
>
> And a Irish guy I know I address as...oh never mind-

Oh, I see, it was a term of endearment, sorry, I missed that, my bad.
 
Tim McNamara wrote:
>
> So I'm not sure where the flex you say you experienced would be coming from. Grossly
> undertensioned wheels, I can see, but I'd doubt that you'd be riding those. Are the tires the same
> on all these wheels?

Could it be coming from the wheels resisting the resultant moment around a fore and aft axis from
pedaling hard?

--
Andy Morris

AndyAtJinkasDotFreeserve.Co.UK

Love this: Put an end to Outlook Express's messy quotes
http://home.in.tum.de/~jain/software/oe-quotefix/
 
It seems much of what was said earlier is lost to some readers. It might help to follow the course
of the thread as in this one.
-------------------------------------------------------------------

Mike Shaw writes:

>>>>> Is tying and soldering really worth the effort?

>>>> Yes, it certainly is. It improves the quality of the wheel. It extends its life expectancy
>>>> without influencing the spoke pre-tension.

>>>>> And so I ask: what (if anything) is wrong with this argument?

>>> Nope, When using aluminum rims and then the wheel is ridden, the aluminum rim WILL become
>>> deformed somehow. When it does, it changes the tension, has to. By tying and soldering, it helps
>>> to reduce spoke at the flange movement of a too loose spoke(due to the deformed rim),
>>> particularly on left side rear, making a broken spoke there much less likely.

>> I think you would be more credible if you showed some evidence for this contention and explain
>> what happens if the same wheel is used without this treatment. Repeating this claim may let it
>> live a while longer but it does not hold up to any analysis. How do you explain that wheels that
>> are not tied and soldered (most wheels) survive all manner of loading without problems? I am
>> curious about what you think of measurements made on the same wheels before and after tying and
>> soldering that show no measurable change in rigidity to side loads and rear wheel torque.

So Mike, what do you find unbelievable about this statement and why would you prefer to believe the
one to which it responds. That is what you seem to be saying.

>>> Of course Jobst will slam me for this, but, so what else is new???

>> That is not a good defense of your hypothesis and it does not deter me from presenting the facts
>> as they were measured. I'm not sure what you mean by "slam."

>>> I choose to believe Gerd on this... who has built more wheels than Jobst and me put together...

>> I know a man who has poured more cubic yards of concrete into prestressed concrete structures
>> than you and I, but he does not understand the stresses in these structures. From what you say, I
>> detect an anti-intellectual tone, a complaint that was broadly heard when "the Bicycle Wheel"
>> came off the press, especially the one of: "Hey! Who's built more wheels, me or this guy from the
>> ivory tower?"

> I'm not an anti-intellectualist, but some of the stuff that engineers try and pass off directly
> flies in the face of personal experience. eg: frame materials all riding alike because they have
> the same stiffness factors, aero wheels not being faster than "normal" wheels, its not the frame,
> its the wheels, dummy, etc.

Let's not get into platitudes. What precisely do you find should be otherwise in this thread? I
responded to an unsupported claim that ignores that the subject has been studied and measured. You
chime in with you doubt what engineers report. I suggest you not drive a car or fly in an aircraft,
these things being designed by engineers, many of whom have never flown an airplane or driven a race
car (such as I who designed a large part of an F1 car that won a Grand Prix.)

> I have no experience whether tied and soldered wheels are indeed stronger/safer/etc. now, but they
> probably were at some point, otherwise why bother? Is there a need to tie and solder wheels now?
> Probably not, but it shows that someone really cares about what they're doing to spend the time
> and effort to do it right.

So why are you complaining... or are you complaining? What is doing it right in your estimation? I
suspect you haven't seen "the Bicycle Wheel" or you wouldn't say that most likely. Wheel builders
who speak out most adamantly against the book have not read it.

> When engineers scratched their heads and said that bumblebees can't fly, it just proved that
> sometimes, the guys who have actually done the job know much, much more than those engineers in
> the ivory towers.

I guess we'll have to hear that old saw, a typical mainstay of anti-intellectuals, for another
century or so. That's such a weak crutch you should be embarrassed to repeat it. You probably
believe that someone actually said that. In fact it was uttered in conjunction with a superficial
flight analysis of that was out of scale and not serious, the engineer knowing full well that such
insects can fly.

http://www.sciencenews.org/sn_arc97/3_29_97/mathland.htm

> Your statistical sample of a few wheels, under your riding conditions: weight, ability, etc. is
> woefully inadequate when compared to the professional mechanic that has built wheels for thousands
> of customers.

I am not citing a statistical sample. You sound like a bumblebee-ist looking for an equation.

> So, while I'm not an anti-intellectualist, I reserve the right to think for myself. If what the
> intellectualist flies in the face of personal observation, I'm going to go with what I've actually
> seen, felt, experienced rather than believe everything blindly.

The implication is that engineers are blind and lacking practical experience while mechanics are
savant and perceptive.

> So, that's my $0.02, next?

You don't get any change for such a negative contribution. Go to school.

Jobst Brandt [email protected] Palo Alto CA
 
"Qui si parla Campagnolo" <[email protected]> wrote in message
news:[email protected]...
> PeterCole-<< What's with that? We all know the image you're trying to
conjure
> with that
> > title.
>
>
> << Oh, I see, it was a term of endearment, sorry, I missed that, my bad.
>
> 'We all know', all but me I guess...

Well, I'll apologize again. I jumped to the conclusion the term might have something to do with
stereotypes. All that engineer bashing "got my Irish up", if you know what I mean.
 
On Mon, 03 Mar 2003 21:25:44 -0600 Tim McNamara <[email protected]> wrote:

>In article <[email protected]>, Terry Morse <[email protected]> wrote:

>> How much mileage do folks get out of Phil Wood hub bearings? I've never been inclined to try
>> them, but I know some long distance riders who swear by them for wet conditions.
>
>I've got 18-20,000 miles on my set and they spin between the fingers smoothly just like new. But
>they have not had a lot of rain exposure and I would expect some problems if I did.

Mine are 30+ years old and I have no idea how many miles are on them. I commuted on them for many
summers, and still do.

-
-----------------------------------------------
Jim Adney [email protected] Madison, WI 53711 USA
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