Rim Failure

jim beam said:

of course. what interests me is that cracked fully socketed rims,
including ma2's, have been seen on this group many times, but the
the coincidence of brandt's immortal words of rim destruction
"tension as high as the rim will bear", highly dished rears with
8/9/10 speed hubs [which radically increases drive side spoke
tension on lateral loading - a loading mode that's also aggressively
denied due to inconvenience] and anodizing seem to conveniently
escape our "expert". <snip snide rant and character assassination>

Your obsession with Jobst is showing again, jim. It's unhealthy and
you really ought to consider getting a life.

As I said in my reply to Mike, I've cracked two Open Pros, silver
anodized, 32 spokes, laced to a Campy 9 speed hub. In both cases the
rims lasted under 2000 miles becore cracking. I replaced the Open
Pros with MA2 rims front and back, and those rims now have 15,000
miles on them with no sign of cracking or failure. I built all three
rear wheels, using the same Jobstian techniques and the same spoke
tension per my Wheelsmisth tensiometer, and DT 14/15 g spokes in all
cases. So, as far as I cvan manage it, the only variable changed is
the rim.

I've also got an MA2 laced to a Shimano 9 speed Ultegra hub, which has
been used for about 12,000 miles in brevets, over the Alps, in
Paris-Brest-Paris, and lots of training and general riding miles. No
cracks or signs of failure.

I've had about a dozen rims fail, all of them anodized and on 6, 7 and
9 speed wheels- always the rear wheel and often in no more than 1000
miles of riding. This has happened whether i built the wheels or
someone else did. I have had zero non-anodized rims fail, even those
without eyelets or sockets, in 40 years of riding bikes (although
that's unfair, as I rode steel rims for the first 11 years of bike
ownership). The one exception was a Mavic Cosmic rim what appeared to
be clear coated rather than anodized, and failed because the spoke
nipple carriers that inserted into the rim did not match the interior
profie of the rim, and thus all the tension was bearing on a very
small area.

I have one remaining anodized rim on a rear wheel, an MA3 laced to a
Bendix coaster brake hub. I think that wheel has about 3,500 to 4,000
miles on it and with 36 spokes and zero dish, it just may hold up. I
spent a lot of time searching through the bike shop's stock to find
the one with the least amount of crazing in the anodized layer around
the spoke holes.

jim beam said:

Wayne Pein said:

jim beam said:

1. the outside corners being thicker than the walls - bizarre.
2. wall thickness the same as braking surface thickness - modern
machined rims are usually /thicker/ at the brake surface.
3. the profile of the rim hook is less aggressive than say an open
pro. maybe there were tire blow-offs.

compare:
http://www.excelsports.com/new.asp?page=8&description=Open+Pro+Road+Rim&vendorCode=MAVIC&major=1&minor=25

I don't think one can conclude these things from the diagrams.

Interestingly, I've got both MA-2s and Open Pros, and the measured
distance between the rim hooks is 13.5 mm for the MA-2 and 14.5 mm for
the Open Pro.

what does measuring the distance between them tell you about the hook
profile?????????? that's like measuring the distance between the two
wheels and concluding that the saddle is at the correct height.

Nothing. I never said it mattered. You inferred meaning.

Wayne

Dans le message de news:[email hidden],
Tim McNamara <[email hidden]> a réfléchi, et puis a déclaré :

Quoted message said:

jim beam said:

Tim McNamara said:

jim beam <[email hidden]> writes:

> Chalo wrote:
>
>> jim beam wrote:
>>
>>
>>> no, i won't take your wheel because:
>>>
>>> 1. my wheel is better in cross winds. i commute across the
>>> golden gate bridge, and that's a real issue some days.
>>
>> I had to chew on this a while in case I discovered some hidden
>> meaning behind what you were saying here. But I have thought it
>> over to my satisfaction and this is my take on it: You must be
>> delirious if you thing that eight ordinary wire spokes have more
>> of an impact on stability in crosswinds than a deep section rim
>> does. (And we know that you approve of deep section rims.)
>> Suceptibility to crosswinds is not a shortcoming of high spoke
>> count wheels, full stop.
>
> chalo, with respect, you're simply repeating the usual r.b.t rant
> without bothering to test for yourself.

Yes, I'm sure Chalo has hardly ever ridden a bike.

> come down here to sf on a windy day. i'll lend you a pair of
> shimano r540's [DEEP rim, 16 spokes front & rear], a pair of mavic
> cosmos [rim like open pro, 24 spoke front, 28 spoke rear] and 3
> pairs of hand builts, with 32 or 36 spoke front & rear, open pro,
> differing spoke gauges. on the golden gate bridge in the spring or
> fall, we're not talking a balmy summer breeze, we're talking 30+
> mph cross winds.

And are you proposing that a 30 mph wind on the Golden Gate Bridge
is
different than a 30 mph wind in, say, Minnesota? That winds or
wheels somehow act differently where you live? I realize that some
things are a bit different in SF compared to the rest of America,
but I didn't think that included the laws of physics.

> the differences between wheels in this situation are easily
> distinguished because they are so large. and guess what, the deep
> rim shimanos are not the worst, in fact, they're pretty much even
> with the cosmos wheels as the best. the worst, by far, are the
> open pro/36 spoke wheels. don't believe it? dig back through the
> archive to when this was last discussed.

I don't believe it because it doesn't make sense.

translation: you don't /think/ it makes sense. truth is, i didn't
expect this result either, but it's what i've observed in practice.
you're welcome to disagree, but please don't do so without at least
testing for yourself.

Quoted message said:

Look at the wheel from the side, and the deep-section rims present
much more frontal area to the wind than the Open Pros do. A few
less spokes cannot make up for the vastly larger surface of the
rim.

You dodged this point, the one that explains why your claim doesn't
make sense.

Quoted message said:

Quoted message said:

And before you moan that I haven't tested it, I've owned and used
Mavic deep-section wheels as well as Open Pros.

you may have owned different rims, but you /still/ don't say you've
owned & ridden low spoke count wheels - which would allow you to
have opinion based on experience.

Jeez Louise, jim, are you really that desperate to "win" these
discussions? Yes, I have owned and ridden low count wheels, if 20 and
24 spokes qualify in your book as low spoke counts. The wheels in
question were Mavic Cosmics, from memory the rims being 5-6 cm tall.
I have owned and ridden wheels with 32, 36 and 48 spokes and standard
box-section rims, too. Does that clarify wherefrom I speak? Am I
permitted to have an opinion now? Sheesh.

You're certainly entitled to an opinion, but you're hardly as entertaining
as beam.
--
Sandy

The above is guaranteed 100% free of sarcasm,
denigration, snotty remarks, indifference, platitudes, fuming demands that
"you do the math", conceited visions of a better world on wheels according
to [insert NAME here].

Dans le message de news:[email hidden],
Tim McNamara <[email hidden]> a réfléchi, et puis a déclaré :

Quoted message said:

jim beam said:

of course. what interests me is that cracked fully socketed rims,
including ma2's, have been seen on this group many times, but the
the coincidence of brandt's immortal words of rim destruction
"tension as high as the rim will bear", highly dished rears with
8/9/10 speed hubs [which radically increases drive side spoke
tension on lateral loading - a loading mode that's also aggressively
denied due to inconvenience] and anodizing seem to conveniently
escape our "expert". <snip snide rant and character assassination>

Your obsession with Jobst is showing again, jim. It's unhealthy and
you really ought to consider getting a life.

Ever notice how terriers are really annoying, since they go after any bait
whatsoever.
Pay attention here !! Same goes for unrelenting idol worshipers.
--
Sandy

The above is guaranteed 100% free of sarcasm,
denigration, snotty remarks, indifference, platitudes, fuming demands that
"you do the math", conceited visions of a better world on wheels according
to [insert NAME here].

Tim McNamara said:

jim beam said:

Tim McNamara said:

jim beam <[email hidden]> writes:

>Chalo wrote:
>
>
>>jim beam wrote:
>>
>>
>>
>>>no, i won't take your wheel because:
>>>
>>>1. my wheel is better in cross winds. i commute across the golden
>>>gate bridge, and that's a real issue some days.
>>
>>I had to chew on this a while in case I discovered some hidden
>>meaning behind what you were saying here. But I have thought it
>>over to my satisfaction and this is my take on it: You must be
>>delirious if you thing that eight ordinary wire spokes have more
>>of an impact on stability in crosswinds than a deep section rim
>>does. (And we know that you approve of deep section rims.)
>>Suceptibility to crosswinds is not a shortcoming of high spoke
>>count wheels, full stop.
>
>chalo, with respect, you're simply repeating the usual r.b.t rant
>without bothering to test for yourself.

Yes, I'm sure Chalo has hardly ever ridden a bike.

>come down here to sf on a windy day. i'll lend you a pair of
>shimano r540's [DEEP rim, 16 spokes front & rear], a pair of mavic
>cosmos [rim like open pro, 24 spoke front, 28 spoke rear] and 3
>pairs of hand builts, with 32 or 36 spoke front & rear, open pro,
>differing spoke gauges. on the golden gate bridge in the spring or
>fall, we're not talking a balmy summer breeze, we're talking 30+
>mph cross winds.

And are you proposing that a 30 mph wind on the Golden Gate Bridge
is
different than a 30 mph wind in, say, Minnesota? That winds or wheels
somehow act differently where you live? I realize that some things
are a bit different in SF compared to the rest of America, but I
didn't think that included the laws of physics.

>the differences between wheels in this situation are easily
>distinguished because they are so large. and guess what, the deep
>rim shimanos are not the worst, in fact, they're pretty much even
>with the cosmos wheels as the best. the worst, by far, are the open
>pro/36 spoke wheels. don't believe it? dig back through the
>archive to when this was last discussed.

I don't believe it because it doesn't make sense.

translation: you don't /think/ it makes sense. truth is, i didn't
expect this result either, but it's what i've observed in practice.
you're welcome to disagree, but please don't do so without at least
testing for yourself.

Quoted message said:

Look at the wheel from the side, and the deep-section rims present
much more frontal area to the wind than the Open Pros do. A few
less spokes cannot make up for the vastly larger surface of the
rim.

You dodged this point, the one that explains why your claim doesn't
make sense.

Quoted message said:

Quoted message said:

And before you moan that I haven't tested it, I've owned and used
Mavic deep-section wheels as well as Open Pros.

you may have owned different rims, but you /still/ don't say you've
owned & ridden low spoke count wheels - which would allow you to
have opinion based on experience.

Jeez Louise, jim, are you really that desperate to "win" these
discussions? Yes, I have owned and ridden low count wheels, if 20 and
24 spokes qualify in your book as low spoke counts. The wheels in
question were Mavic Cosmics, from memory the rims being 5-6 cm tall.
I have owned and ridden wheels with 32, 36 and 48 spokes and standard
box-section rims, too. Does that clarify wherefrom I speak? Am I
permitted to have an opinion now? Sheesh.

My Cosmics were very much more susceptible to crosswinds than my
standard wheels. Gusts of wind would push me laterally towards or
away from the edge of the road. It was unpleasant on really windy
days with unpredictable gusts, in particular. In fact I found no
benefit with these wheels and enough drawbacks that I got rid of them
to a time triallist.

I am suggesting that you are either (1) mistaken in your observations
or (2) misattributing cause and effect. I suggest at least one other
possible mechanism for your observations, if they are correct, which
is the greater mass of the deep section rims providing more of a
flywheel effect. There are other factors to be considered, including
tires, inflation, steering geometry, load on the bike, etc. You'd
have to be keeping all those things constant to be able to make a
meaningful comparison.

please read ron's post, and the archive on this subject. i want to see
your comment before we continue.

Tim McNamara said:

jim beam said:

of course. what interests me is that cracked fully socketed rims,
including ma2's, have been seen on this group many times, but the
the coincidence of brandt's immortal words of rim destruction
"tension as high as the rim will bear", highly dished rears with
8/9/10 speed hubs [which radically increases drive side spoke
tension on lateral loading - a loading mode that's also aggressively
denied due to inconvenience] and anodizing seem to conveniently
escape our "expert". <snip snide rant and character assassination>

Your obsession with Jobst is showing again, jim. It's unhealthy and
you really ought to consider getting a life.

if you have more tolerance for having smoke blown up your kilt than i
do, either you don't know it or you enjoy it. neither reason is my problem.

Quoted message said:

As I said in my reply to Mike, I've cracked two Open Pros, silver
anodized, 32 spokes, laced to a Campy 9 speed hub. In both cases the
rims lasted under 2000 miles becore cracking. I replaced the Open
Pros with MA2 rims front and back, and those rims now have 15,000
miles on them with no sign of cracking or failure. I built all three
rear wheels, using the same Jobstian techniques and the same spoke
tension per my Wheelsmisth tensiometer, and DT 14/15 g spokes in all
cases. So, as far as I cvan manage it, the only variable changed is
the rim.

so you say, but tim, seriously, of all the bile vented here at mavic
rims, how much of it is for open pros? the lemming mockery instinct so
commonly exhibited here would surely join in if there were corroborative
issues to report. as i recall, only you and one other in the whole time
i've read this group have reported open pro cracking problems. and both
of you have reported repeated failures at low mileage. the other
cracker admits to using excess spoke tension. why is that?

my experience of this rim is different. i've had open pros on wheels
with over 10k miles, ["cd" hard anodized], weigh #205 and have had no
cracking problems whatsoever. i've had the mavic tick, but that's
hardly a serious structural failing. in view of this, the question is,
how do /you/ have such consistent problems at such low mileage with a
rim with a good record? there /has/ to be a reason. if it were the rim
wouldn't this group would be swamped with reports?

Quoted message said:

I've also got an MA2 laced to a Shimano 9 speed Ultegra hub, which has
been used for about 12,000 miles in brevets, over the Alps, in
Paris-Brest-Paris, and lots of training and general riding miles. No
cracks or signs of failure.

I've had about a dozen rims fail, all of them anodized and on 6, 7 and
9 speed wheels- always the rear wheel and often in no more than 1000
miles of riding. This has happened whether i built the wheels or
someone else did. I have had zero non-anodized rims fail, even those
without eyelets or sockets,

tim, with respect, you refer to ma2's as non-anodized, when in fact they
are anodized. i therefore request that you differentiate between
"silver" and "non-anodized". i also ask, if these rims exhibit
intergranular cracking modes, as they appear to do, how can it be
anodizing initiated fatigue? pics of the two different fracture surface
types have been shown on this group many times, but i don't recall
anyone bothering to point out that the rim fracture surfaces exhibit
none of the surface features [transgranular cracking, beach marks,
cracking perpendicular to stress, not aligned with the extrusion axis,
etc.] seen in other fatigue failures. i know you like your arguments
cut & dried, but that's simply not possible here - there are too many
anomalies for rim cracking to be simply anodizing initiated fatigue.

Quoted message said:

in 40 years of riding bikes (although
that's unfair, as I rode steel rims for the first 11 years of bike
ownership). The one exception was a Mavic Cosmic rim what appeared to
be clear coated rather than anodized, and failed because the spoke
nipple carriers that inserted into the rim did not match the interior
profie of the rim, and thus all the tension was bearing on a very
small area.

I have one remaining anodized rim on a rear wheel, an MA3 laced to a
Bendix coaster brake hub. I think that wheel has about 3,500 to 4,000
miles on it and with 36 spokes and zero dish, it just may hold up. I
spent a lot of time searching through the bike shop's stock to find
the one with the least amount of crazing in the anodized layer around
the spoke holes.

i have a wheel with a "cd" ma3 rim, ~9k miles. no cracks.

Ron Sonic writes:

If you changes your ISP to Sonic.net your sig would look even wackier.

Quoted message said:

Here in Tampa, this time of year, the wind will grab 32s Opens and
try to just rip them out from under me.

Quoted message said:

The deep rim has the same drag to side wind across its diameter.
The drag of a spoke is not the same all the way around the spinning
wheel. The ones at the greatest airspeed from forward motion will
be the ones most affected by a side wind. This is a whole nother
thing from a stability standpoint.

Let's get to the bottom of this. How does rotation of the wheel
increase the effective (lateral) steering force from side winds. I
think there is a mix of drag, work, and power confusing this issue.
Please explain.

Jobst Brandt

"Sandy" <[email hidden]> wrote in
news:[email hidden]:

Quoted message said:

Dans le message de news:[email hidden],
Tim McNamara <[email hidden]> a réfléchi, et puis a déclaré
:
You're certainly entitled to an opinion, but you're hardly as
entertaining as beam.

Right, it is really going to be interesting to see how jim tries to
wiggle his way out of this one.

Tim McNamara said:

jim beam said:

of course. what interests me is that cracked fully socketed rims,
including ma2's, have been seen on this group many times, but the
the coincidence of brandt's immortal words of rim destruction
"tension as high as the rim will bear", highly dished rears with
8/9/10 speed hubs [which radically increases drive side spoke
tension on lateral loading - a loading mode that's also aggressively
denied due to inconvenience] and anodizing seem to conveniently
escape our "expert". <snip snide rant and character assassination>

Your obsession with Jobst is showing again, jim. It's unhealthy and
you really ought to consider getting a life....

"jim beam" is actually an AI program designed to harass and annoy Jobst
Brandt. A bug in the program prevents it from using capital letters. 😉

--
Tom Sherman - Fox River Valley (For a bit)

In article <[email hidden]>,

Johnny Sunset said:

Quoted message said:

Your obsession with Jobst is showing again, jim. It's unhealthy and
you really ought to consider getting a life....

"jim beam" is actually an AI program designed to harass and annoy Jobst
Brandt. A bug in the program prevents it from using capital letters. 😉

If jb - as opposed to JB! - is representative of the state of AI,
scientists need to apply themselves more.

Luke

Sandy said:

You're certainly entitled to an opinion, but you're hardly as
entertaining as beam.

Thank you!

jim beam said:

ah, the wise words of an individual that's prepared to think for them
self and bother to do their own testing, not regurgitate the mindless
drivel of the hopelessly inexpert that they read on usenet.

Or the made-up rantings of a "used-to-be-mettalurgist" who makes up
things for the sole purpose of being the avenging angel of
rec.bicycles.tech, the hard man who rails against everything in the
newsgroup so as to be seen as the radical genius of everything bikes and
metals....

Quoted message said:

3. my wheel is fine!

i don't care or endorse any one wheel or product. but i /do/ care when
mindless garbage gets repeated here as fact when it's blatantly untrue.
what's true is that the wheel i'm using has withstood service as
described, contrary to "theory" here on rbt.

You really ought to stop making up things, jimbo. Take up the
suggestion and prove to others that you are in fact stating truth.

there's a waggonload of

Quoted message said:

other myths on similar topics repeated here, all with a common source.

Make that "sources". Include yourself on that one, beamboy.

Quoted message said:

i'd repeat a few of them, but it gets so very very dull to replicate
what google will reveal to you in just a few seconds.

Indeed. Try "jim beam".

Tim McNamara said:

jim beam <[email hidden]> writes:

Huh? Mavic made my favorite rims. I have had poor results with a
number of Mavic products. Is telling the trouth about that somehow
bilious in the world you live in?

I used to buy nothing but Mavic, I was a very loyal customer, figured
they knew their stuff and wouldn't mislead their customers. But now
that I've experienced major cracks around eyelets and splits down the
spoke bed I've opened my rim searches to all the other companies.

Greg

--
"All my time I spent in heaven
Revelries of dance and wine
Waking to the sound of laughter
Up I'd rise and kiss the sky" - The Mekons

jim beam said:

so, do you accept everything else at face value? for instance:

do you accept that anodizing is responsible for rim cracking even though
anodizing cracks are not aligned with the fracture surface and the
fracture has an intergranular appearance?

Appearance of inter-granular or trans-granular fracture surfaces don't
indicate the cause of brittle fracture (whether it be anodizing or
chips); the material property and the load dictate the type of fracture,
and saying whether intergranular or transgranular appearances are
present say nothing against anodizing as being the cause of brittle
failure. No wonder you're an 'ex-mattalurgist".

Quoted message said:

do you accept that stainless steel, a material with no fatigue endurance
limit, can be made fatigue proof?

Stainless steel does have fatigue limits, and these depend on the type
of stainless steel:

http://www.outokumpu.com/files/Group/HR/Documents/Fatigueproperties.pdf

Doesn't take long to Google that.

Quoted message said:

do you accept that bike bearings are elasto-hydrodynamically separated?

Pick up any text book when you go to your "library", beamboy.
Elastohydrodynamics define ball-race contact with lubrication in ball
bearings. Obviously you didn't use to be a tribologist as well.

Quoted message said:

etc. [it's a long and very boring list.]

if so, you might be disappointed by reality.

No, just disappointed by _your_ reality, jimbo. Go for another shot,
won't you?

jim beam said:

Tim McNamara wrote:

Quoted message said:

Quoted message said:

Your obsession with Jobst is showing again, jim. It's unhealthy and
you really ought to consider getting a life.

if you have more tolerance for having smoke blown up your kilt than i
do, either you don't know it or you enjoy it. neither reason is my
problem.

The only smoke and bile I see are coming from your rants, jimbo.
Whether or not you just wrote them, or whether we "dig through the
archives".

Quoted message said:

As I said, double walled rims with sockets were not idly introduced.
You and I rode tubulars on them and never heard of cracked rims.
Those wheels are gathering dust but are still as good as new with
their epoxied insulators on which to glue tubulars.

Jobst Brandt

But how could a tubular rim of reasonable weight *not* be one heck of a lot
stronger than what we ride on today? When you think about how much less
there is to a tubular rim- no sidewalls to support the tire- and the weights
weren't that much less (350-360 grams for most moderately-light rims; 300
grams for the stupid-light stuff that you & I couldn't get away with,
although I confess I tried) than modern clinchers.

-- Mike-- Chain Reaction Bicycles
www.ChainReactionBicycles.com

<[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Mike Jacoubowsky said:

Quoted message said:

> I'm somewhat cynical that it was the fully-"socketed" feature that
> made the difference. Why? Because it seemed that the top flange of
> the "socket" often wasn't entirely flush with the upper surface of
> the rim, plus I don't recall seeing rims where the upper (inside)
> surface had been deformed when a spoke attempted to pull through
> the bottom. But could be that I never saw this because the
> fully-socketed feature nearly eliminated the possibility of such
> damage?

Quoted message said:

Quoted message said:

> Guess I should take an old rim and cut a cross-section out, right
> at a socket, and see how the fit really is.

Quoted message said:

Quoted message said:

I have piles of used up and some new MA-2 rims as well as Fiamme
tubular tire rims equipped with sockets. These are well seated and
show no gaps under them. On the other hand, if it's not lack of
sockets, to what do you attribute rims cracking around spokes,
something unknown in earlier times when according to some, the
aluminum alloys were inferior although rims could withstand more
tension?

Quoted message said:

But I have seen cracked, fully-socketed rims in the past.
Specifically Mavics. I'll admit it was a much-less-common thing
than now, but I'm not sure whether that's the different
eyelet/socket/none-of-the-above differences, or the anodized
finishes on current rims.

Memories are short, and besides many readers of this newsgroup did not
experience Mavic introducing hard anodizing on their rims, advertising
how much harder than aluminum this coating was and that rims were
therefore stronger. These rims, early MA-40's, where cracking
failures first appeared on what was merely a hard anodized MA-2, the
most popular and widely used rim in the western world.

As I said, double walled rims with sockets were not idly introduced.
You and I rode tubulars on them and never heard of cracked rims.
Those wheels are gathering dust but are still as good as new with
their epoxied insulators on which to glue tubulars.

Jobst Brandt

Mike Jacoubowsky said:

Quoted message said:

As I said, double walled rims with sockets were not idly
introduced. You and I rode tubulars on them and never heard of
cracked rims. Those wheels are gathering dust but are still as
good as new with their epoxied insulators on which to glue
tubulars.

Quoted message said:

But how could a tubular rim of reasonable weight *not* be one heck
of a lot stronger than what we ride on today? When you think about
how much less there is to a tubular rim- no sidewalls to support the
tire- and the weights weren't that much less (350-360 grams for most
moderately-light rims; 300 grams for the stupid-light stuff that you
& I couldn't get away with, although I confess I tried) than modern
clinchers.

The wall thicknesses were similar and those that didn't have sockets
failed. Recall Nisi and Martano rims that had only washers and not
even eyelets. They didn't work any better than the stuff we see now.

Jobst Brandt

Luke said:

In article <[email hidden]>,

Johnny Sunset said:

Quoted message said:

Your obsession with Jobst is showing again, jim. It's unhealthy and
you really ought to consider getting a life....

"jim beam" is actually an AI program designed to harass and annoy Jobst
Brandt. A bug in the program prevents it from using capital letters. 😉

If jb - as opposed to JB! - is representative of the state of AI,
scientists need to apply themselves more.

The next version is almost ready, it's developmental codename is "Racter."

Ron

RonSonic said:

The deep rim has the same drag to sidewind across its diameter. The drag of a
spoke is not the same all the way around the spinning wheel. The ones at the
greatest airspeed from forward motion will be the ones most affected by a side
wind.

True, but why would that matter? That is, if most of the lateral force is
due to the rim---and that seems to be the case--why be concerned whether a
fraction of the lateral force is not constant around the hub?

Joe

Quoted message said:

Quoted message said:

Quoted message said:

As I said, double walled rims with sockets were not idly
introduced. You and I rode tubulars on them and never heard of
cracked rims. Those wheels are gathering dust but are still as
good as new with their epoxied insulators on which to glue
tubulars.

Quoted message said:

But how could a tubular rim of reasonable weight *not* be one heck
of a lot stronger than what we ride on today? When you think about
how much less there is to a tubular rim- no sidewalls to support the
tire- and the weights weren't that much less (350-360 grams for most
moderately-light rims; 300 grams for the stupid-light stuff that you
& I couldn't get away with, although I confess I tried) than modern
clinchers.

The wall thicknesses were similar and those that didn't have sockets
failed. Recall Nisi and Martano rims that had only washers and not
even eyelets. They didn't work any better than the stuff we see now.

Jobst Brandt

But the failure mode for both Nisi and Martano was "flattening" (they'd
simply get squished a bit, with the sidewalls bowing outward). I don't
recall issues with failures from cracking at the spoke/rim junction. Just
darned soft rims, near as I could tell.

Martano rims, in particular, were the most absurdly-overrated pieces of junk
I ever came across. Lots of hype about how they were supposed to be so
great, but yikes, all I ever saw were squished and flattened versions after
a short time on the road. Mine included.

--Mike-- Chain Reaction Bicycles
www.ChainReactionBicycles.com