ideal clincher tire
dianne_1234
It would have:
Data proving low rolling resistance (easier to pedal)
Guaranteed not-to-exceed weight (or my money back)
Easy to mount (not tight fitting)
Smooth transition from tread to sidewall (better aerodynamics)
Data proving good lean traction (faster cornering)
It wouldn't have:
belts
anti-pinch bead
toughened sidewalls
tread pattern
It might have:
Carbon or Silica (or Kevlar or...) in the tread rubber?
Colors?
Dual hardness tread?
Folding?
What do you think?
Paolo Sant'Ambrogio
Record 10 hubs
DT Competition 14-18 & aluminum nips.
Mavic Open Pro "SUP" "CD" "Maxtral" one of these means black anodized 32
holes.
Lacing is 2 cross front 3 cross rear. Drive side nipples are brass.
Used The Book, and on the front wheel I got very high tension, to the point
that the nipples are difficult to turn. After stress reliving per book with
lather gloves on 4 parallel spokes I do not get the taco deformation. I am
unwilling to tension further as the nipples will strip at the squares. The
Park spoke wrench is difficult to turn.
The Open Pro is not an aero rim it has a cross sectional area bigger than
the MA2 but not as big as many aero rims.
Do I now have a over tensioned wheel that will taco when braking when
descending?
The Open Pro is common has anybody built a wheel and tensioned to taco per
The Book?
Paolo Sant'Ambrogio
Santa Monica, CA
John Henderson
> Drive side nipples are brass.
That's unbeatable as an answer to dianne_1234's original question
in this thread.
John
Harris
"Paolo Sant'Ambrogio" wrote:
> Building a set of wheels, components are:
> Record 10 hubs
> DT Competition 14-18 & aluminum nips.
14-18? Is there really such an animal? I wouldn't use that!
> Mavic Open Pro "SUP" "CD" "Maxtral" one of these means black anodized
32
> holes.
>
> Lacing is 2 cross front 3 cross rear. Drive side nipples are brass.
>
> Used The Book, and on the front wheel I got very high tension, to the
point
> that the nipples are difficult to turn. After stress reliving per book
with
> lather gloves on 4 parallel spokes I do not get the taco deformation. I
am
> unwilling to tension further as the nipples will strip at the squares.
The
> Park spoke wrench is difficult to turn.
Are the spoke threads well lubed? Also, you might want to try a "Spokey"
spoke wrench. The taco doesn't have to be extreme, but you should get a
definite wave that is easily seen.
If you read the book, I'm surprised that you're using anodized rims, and
aluminum nipples.
Art Harris
Harris
"dianne_1234" wrote:
> It wouldn't have:
> belts
> anti-pinch bead
Anti-pinch bead? That's a new one to me.
Art Harris
jim beam
statement. almost all rims are anodized, whether it be silver or any
other color. /all/ mavic rims are anodized. period. it is a
frequently repeated misconception that "black" = anodized, and "silver"
does not. the rim cracking flaws commonly attributed to "anodizing" on
this forum are typically due to extrusion defects and /not/
anodizing-induced fatigue. the faq's really need to be updated.
the truth of the matter is that anodized bike components have been the
norm for decades. brake calipers & brake levers, cranks & seat posts,
handlebars & stems, all are anodized and none have been excoriated on
this forum for their "anodizing induced fatigue", and for good reason!
jb
Chris Zacho The Wheelman
into the casing.
Smooth transition from sidewall to a slight "point" in the "tread"
center (cross section). Less rubber on road when upright, more rubber
when leaning (translation,- less rolling resistance straight, more
traction turning).
No tread, per se, but a slight "negative" siping in an otherwise slick
surface.
Oval design gave same rim protection for given tire size with narrower
actual profile = more aerodynamic(?)
Unfortunately, you missed out. Hutchinson stopped production sometime in
the late nineties. Nashbar had a close out recently (must have had some
hidden in storage). But not offering them any more.
May you have the wind at your back.
And a really low gear for the hills!
Chris
Chris'Z Corner
"The Website for the Common Bicyclist":
http://www.geocities.com/czcorner
jobst....@stanfordalumni.org
> Used The Book, and on the front wheel I got very high tension, to
> the point that the nipples are difficult to turn. After stress
> reliving per book with lather gloves on 4 parallel spokes I do not
> get the taco deformation. I am unwilling to tension further as the
> nipples will strip at the squares. The Park spoke wrench is
> difficult to turn.
I suspect you are not getting the spokes tight if you have come to a
point where you cannot turn the nipples. Properly lubricated nipples
will turn until the spoke snaps regardless of your spoke wrench (if it
has a reasonably close fit). My spoke wrench is a parallel, hardened
steel VAR tool and I can get spokes far tighter than the spokes like.
I see VAR has knuckled under and made a 4-corner (pseudo socket) end
on their trusty old flat jawed wrench. This is not necessary in my
experience. Every time I have been confronted with one of these
"can't turn the nipple any more" sessions, a drop of 30W oil made the
already partially rounded nipple perform as it should. 4-corner spoke
wrenches add a movement (complexity) to spoke nipple engagement that I
prefer to not have.
Oil those spokes as described in the book I assume you have. although
I'm not so sure you read all of what you needed... or we wouldn't be
talking about this here.
Jobst Brandt
jobst....@stanfordalumni.org
Palo Alto CA
Paolo Sant'Ambrogio
same oil that goes in the car. I can see oil at the nipple - socket
circumference. The threads were lubed when the wheel was loosely laced and
the nipple threads were not taken up by the spoke. Each nipple was able to
receive a drop or more of oil.
I looked at the VAR and Spokey tools and like that they grab the soft alum.
nipples on all four corners. The Park grabs on two faces, like a box end
wrench instead of a socket. The Book describes tensioning smaller section
MA2's with brass nipples. The wheels discussed have softer nipples and
greater sectional area.
Apologies for starting this in the wrong thread, and stating the wrong gage,
spokes are DT *14-15* ga., 1.8-2.0 mm
I did experience a taco failure on a descent; truck made u turn, me going
30mph, brake hard, rear skids, bike sideways, I release rear brake, wheel
tacoes. This I'd prefer to avoid.
Steve Shapiro
> Paolo Sant'Ambrogio writes:
snip
> Oil those spokes as described in the book I assume you have. although
> I'm not so sure you read all of what you needed... or we wouldn't be
> talking about this here.
>
> Jobst Brandt
> jobst....@stanfordalumni.org
> Palo Alto CA
Definately oil the threads of the spokes. Also, I found that oiling
the eyelets on the tire side makes tensioning, especially with
aluminum nipples, go smoothly. I put some motor oil on a cotton swab
and lube each eyelet before lacing the wheel. It helps with brass
nipples too. This with Mavic wheels and DT spokes. The only
disadvantage I've found is that I have to clean the wheels thoroughly
after building so that the rim tape will stick.
Steve Shapiro sh...@thermacell.net
Art Harris
> sorry art, i feel compelled to take issue with the "anodized rim"
> statement. almost all rims are anodized, whether it be silver or any
> other color. /all/ mavic rims are anodized. period.
There is much confusion on this subject. Some silver rims have a clear
alodine finish, which is sometimes mistakenly called anodized. Other
rims have a cosmetic light anodized finished. To the best of my
knowledge, black/dark grey rims are hard anodized.
> the rim cracking flaws commonly attributed to "anodizing" on
> this forum are typically due to extrusion defects and /not/
> anodizing-induced fatigue. the faq's really need to be updated.
How do you explain that the MA-2 (polished silver) rim rarely cracked,
but the identical MA-40 (anodized) rim cracked very often? The failure
mechanism is as follows: Cracks form in the anodized layer due to rim
flexing. These cracks act as stress risers, and cause the cracks to
propagate into the rim itself.
Art Harris
Qui si parla Campagnolo
It would have:
Data proving low rolling resistance (easier to pedal)
Guaranteed not-to-exceed weight (or my money back)
Easy to mount (not tight fitting)
Smooth transition from tread to sidewall (better aerodynamics)
Data proving good lean traction (faster cornering) >><BR><BR>
Don't forget cheap...
If it has colors, it doesn't have carbon black..
Sounds like you want a tubular.
Peter Chisholm
Vecchio's Bicicletteria
1833 Pearl St.
Boulder, CO, 80302
(303)440-3535
http://www.vecchios.com
"Ruote convenzionali costruite eccezionalmente bene"
Qui si parla Campagnolo
>><BR><BR>
Gotta ask, why two cross front? It saves the equivalent of about 1 spoke.
<< Used The Book, and on the front wheel I got very high tension, to the point
that the nipples are difficult to turn. >><BR><BR>
Lube the nipps, between nipp and rim??
I doubt you have overtensioned the 14/18(17?)spokes. I wonder if these spokes
are a good choice for the rear as well.
Qui si parla Campagnolo
gage,
spokes are DT *14-15* ga., 1.8-2.0 mm >><BR><BR>
Better choice altho two cross front on a 32h still mystyfies.
David L. Johnson
> It would have:
(1) > Data proving low rolling resistance (easier to pedal)
(2) > Easy to mount (not tight
> fitting)
(3) > Don't forget cheap...
> Sounds like you want a tubular.
Not with (1), (2), and (3) above -- but Peter added (3).
--
David L. Johnson
__o | Become MicroSoft-free forever. Ask me how.
_`\(,_ |
(_)/ (_) |
jim beam
> mistakenly called anodized.
that /is/ anodizing. /all/ current mavic rims are anodized,
irrespective of color. just like campy brake calipers are /all/ anodized.
> knowledge, black/dark grey rims are hard anodized.
"CD" is hard anodized - dark grey color. black is just ordinary
anodizing, but stained or even painted. as you probably know, anodized
finishes are available in any color you care to name on other
components, and this /includes/ "unstained". there are almost /no/
components sold unanodized because while pure aluminum is strongly
corrosion resistant, a lot of it's alloys are not and subject to surface
defects, pitting, etc. anodizing is the lesser of these evils.
> How do you explain that the MA-2 (polished silver) rim rarely cracked,
just so we understand each other, the ma2 was available in silver
anodized and "bright" silver. both were available in the u.s., but from
all the ma2's i've seen, the silver anodized was by far the commonest
- it's the easiest to keep looking good.
> mechanism is as follows: Cracks form in the anodized layer due to rim
> flexing. These cracks act as stress risers, and cause the cracks to
> propagate into the rim itself.
that would be true in the absence of other defects. but as you can see
in this pic,
http://technology.open.ac.uk/materials/mem/images/images_cc/ccf3.gif
the crack is not on the anodized surface and is not even following the
machining lines of the braking surface! it's a jagged intergranular
crack, as it says, following the plane of an extrusion defect. straight
fatigue is transgranular and would more closely follow a fatigue
initiator, such as you rightly say, an anodizing crack or a machining
stress riser.
http://bike-nomad.com/raw_images/p0000401.jpg
on this pic, you can argue that the crack on the left starts with the
anodizing cracks that radiate from the spoke hole where the eyelet gets
punched in. the right hand one however, is clearly tangential - /not/
in line with anodizing cracks but exactly in line with its extrusion
axis. both cracks are again jagged and intergranular - characteristic
of extrusion failure.
you /do/ see cracks in rim anodizing all the time. on a long enough
time frame, because aluminum has no fatigue endurance limit, agreed,
whese could become a problem, but it's not the reason for the rapid
cracking we saw with the ma40 or the examples above. iirc, the ma40 was
mavic's "maxtal" test rim and they badly screwed up it's extrusion
processing. mavic still do screw up from time to time, but they're not
as bad as they used to be.
jb
jobst....@stanfordalumni.org
> Spokes were lubed with the current equivalent of 30w, Mobil 1 5w-30,
> the same oil that goes in the car. I can see oil at the nipple -
> socket circumference. The threads were lubed when the wheel was
> loosely laced and the nipple threads were not taken up by the spoke.
> Each nipple was able to receive a drop or more of oil.
Something doesn't add up here. As I said, I use a straight slotted
spoke wrench with which I can over-tighten spokes without damage to
the flanks of brass nipples. If you cannot tighten the spokes
further, then it is a friction problem between rim and nipple, the
place where resistance to rotation occurs. High friction in spoke
threads would cause spokes to twist off. Spokes wire does not have
large twist resistance and this is a problem with thinner spokes,
especially 1.5mm diameter ones.
> I looked at the VAR and Spokey tools and like that they grab the
> soft alum. nipples on all four corners. The Park grabs on two
> faces, like an end wrench instead of a socket. The Book describes
> tensioning smaller section MA2's with brass nipples. The wheels
> discussed have softer nipples and greater sectional area.
Well?
> Apologies for starting this in the wrong thread, and stating the
> wrong gage, spokes are DT *14-15* ga., 1.8-2.0 mm
> I did experience a taco failure on a descent; truck made u turn, me
> going 30mph, brake hard, rear skids, bike sideways, I release rear
> brake, wheel tacoes. This I'd prefer to avoid.
In a crash, wheels are often the first to go.
jim beam
> spoke wrench with which I can over-tighten spokes without damage to
> the flanks of brass nipples. If you cannot tighten the spokes
> further, then it is a friction problem between rim and nipple
if he's properly lubed, and he says he is, he could be using spokes that
are slightly too long. once he runs out of pre-formed thread, he's then
trying to cut his own, and that will substantially resistance as the
threads bind. not an uncommon problem.
jb
David Damerell
>My ideal clincher tire.
>It would have:
> Data proving low rolling resistance (easier to pedal)
> Guaranteed not-to-exceed weight (or my money back)
> Easy to mount (not tight fitting)
> Smooth transition from tread to sidewall (better aerodynamics)
> Data proving good lean traction (faster cornering)
Ideally one would also like it to be cheap, long-lasting and the size it
claims to be.
--
David Damerell <dame...@chiark.greenend.org.uk> flcl?
jobst....@stanfordalumni.org
>> Some silver rims have a clear alodine finish, which is sometimes
>> mistakenly called anodized.
> that /is/ anodizing. /all/ current mavic rims are anodized,
> irrespective of color. just like campy brake calipers are /all/
> anodized.
Alodine finish is not anodizing. A good test for this is to see if
the surface is conductive, and with alodine it is electrically
conductive.
http://www.microsheencorporation.com/anodizing.htm
>> How do you explain that the MA-2 (polished silver) rim rarely cracked,
> just so we understand each other, the ma2 was available in silver
> anodized and "bright" silver. both were available in the u.s., but
> from all the ma2's i've seen, the silver anodized was by far the
> commonest - it's the easiest to keep looking good.
Those are not the ones that people are referring to. The MA-2 rims
that I have and have used have an electrically conductive mirror like
shiny finish. They are not anodized.
>> mechanism is as follows: Cracks form in the anodized layer due to
>> rim flexing. These cracks act as stress risers, and cause the
>> cracks to propagate into the rim itself.
> that would be true in the absence of other defects. but as you can
> see in this pic,
http://technology.open.ac.uk/materials/mem/images/images_cc/ccf3.gif
Your picture is of a machined sidewall, not an extruded form. The
profile was anodized in the extruded bar condition and is anodized
inside and out. When forming the hoop, the anodized surface crazes
being less elastic than the aluminum substrate that is yielding about
its neutral axis.
> the crack is not on the anodized surface and is not even following
> the machining lines of the braking surface! it's a jagged
> intergranular crack, as it says, following the plane of an extrusion
> defect. straight fatigue is transgranular and would more closely
> follow a fatigue initiator, such as you rightly say, an anodizing
> crack or a machining stress riser.
I disagree with your analysis. This type of cracking was unknown
before the anodizing fad came to rims.
http://bike-nomad.com/raw_images/p0000401.jpg
> on this pic, you can argue that the crack on the left starts with
> the anodizing cracks that radiate from the spoke hole where the
> eyelet gets punched in. the right hand one however, is clearly
> tangential - /not/ in line with anodizing cracks but exactly in line
> with its extrusion axis. both cracks are again jagged and
> intergranular - characteristic of extrusion failure.
I think you ought to inspect some new rims under grazing incidence
light and see that there are myriad cracks in the anodized surface
before the wheel has been ridden. Some of these cracks are larger than
others and some lie on flaws or extrusion irregularities. Back when
hard anodizing was believed to strengthen rims, and thicker was
better, some rims cracked circumferentially into the hollow part of
the profile, leaving the tire secure on one half and the spokes
pulling on the inner half.
> you /do/ see cracks in rim anodizing all the time. on a long enough
> time frame, because aluminum has no fatigue endurance limit, agreed,
> whese could become a problem, but it's not the reason for the rapid
> cracking we saw with the ma40 or the examples above. iirc, the ma40
> was mavic's "maxtal" test rim and they badly screwed up it's
> extrusion processing. mavic still do screw up from time to time,
> but they're not as bad as they used to be.
These cracks are already there when the rim is completed, unused.
Chalo
> I doubt you have overtensioned the 14/18(17?)spokes. I wonder if these spokes
> are a good choice for the rear as well.
He mentioned that his spokes were DT Competition, which are made in
14/15ga. or 15/16ga. S.W.G. 18ga. is equal to 1.22mm, which is not
sufficiently thick for use as spokes.
I would question the use of aluminum nipples as I believe they have a
more pronounced effect on the quality of the build than either lacing
pattern or spoke gauge.
Chalo Colina
Chalo
> My ideal clincher tire.
...
> What do you think?
Black sidewalls. Too many tires with tan sidewalls develop UV-damaged
casings before the tread is used up. Black skinwalls do not seem to
weigh extra, but do prevent sun rot.
Chalo Colina
Werehatrack
have said:
>vecc...@aol.com (Qui si parla Campagnolo) wrote:
>
>> I doubt you have overtensioned the 14/18(17?)spokes. I wonder if these spokes
>> are a good choice for the rear as well.
>
>He mentioned that his spokes were DT Competition, which are made in
>14/15ga. or 15/16ga. S.W.G. 18ga. is equal to 1.22mm, which is not
>sufficiently thick for use as spokes.
Maybe the label on the package was printed sloppily enough for 14/15
to look like 14/18. You're right, 18ga would be way too thin unless
it was a fairly exotic material; more exotic than is likely to be used
for spokes, anyway.
As for the rest...it's been a long time since I laced a whole wheel,
but I recall that aluminum nipples were available then, maybe as a New
Thing...and they were detested by the guys at my lbs of those days. I
didn't ask why, I just followed their advice and stayed with brass.
(Later, as I became more familiar with the many ways that aluminum can
do things that are not exactly welcome, some of the probable reasons
for their dislike of the item became apparent. Along the way, I
became a firm believer in the application of Never-Sieze to steel
threads that had to go into a tapped aluminum hole. And I built a
helicoil and timesert tool collection that covers far too much
territory.)
--
My email address is antispammed;
pull WEEDS if replying via e-mail.
Yes, I have a killfile. If I don't respond to something,
it's also possible that I'm busy.
Rick Onanian
> My ideal clincher tire.
> It might have:
> Colors?
In a shallow but harmless way, colors are cool.
> Dual hardness tread?
Don't know if that makes a difference.
> Folding?
Absolutely. How else are you supposed to carry
an extra one?
> What do you think?
My ideal tire:
-- Leaps onto the rim and mounts itself
-- Inflates the tube, automatically patching any leaks
-- Spins the wheels for me, so I don't have to pedal
-- Can be commanded to fly the bike above the stratosphere
-- Can encase me in a safety shell and work under the ocean
-- Will replace 30 or 40 pounds of my fat with as much muscle
-- Will include side-effect-free automatic birth control
-- Will prevent me from getting in an accident
-- Predicts the winning powerball number for me
...etc.
I think yours was more realistic, though. ;)
--
Rick Onanian
Werehatrack
said:
>jim beam wrote:
>
>> sorry art, i feel compelled to take issue with the "anodized rim"
>> statement. almost all rims are anodized, whether it be silver or any
>> other color. /all/ mavic rims are anodized. period.
>
>There is much confusion on this subject. Some silver rims have a clear
>alodine finish, which is sometimes mistakenly called anodized. Other
>rims have a cosmetic light anodized finished. To the best of my
>knowledge, black/dark grey rims are hard anodized.
Black would likely be a dye in the anodizing, and its presence would
indicate that the finish is not a hardcoat. Hardcoat anodizing, of
the opaque, nonglossy grey variety, generally won't take a dye.
"Decorative" anodizing can be anywhere from a few ten thousandths of
an inch to about .003" in thickness. At the lower end of that range,
it would be hard to believe that the coating could have a bearing on
the failures. At the upper end, I'm now inclined to lean in favor of
there being a relationship, but I don't agree about the mechanism.
>> the rim cracking flaws commonly attributed to "anodizing" on
>> this forum are typically due to extrusion defects and /not/
>> anodizing-induced fatigue. the faq's really need to be updated.
>
>How do you explain that the MA-2 (polished silver) rim rarely cracked,
>but the identical MA-40 (anodized) rim cracked very often? The failure
>mechanism is as follows: Cracks form in the anodized layer due to rim
>flexing. These cracks act as stress risers, and cause the cracks to
>propagate into the rim itself.
Some of this is speculative, but it's based on sound concepts,
presented as an alternative (or perhaps expanded?) explanation; I
think that the mechanism is not what you have stated, although I
suspect that if the anodizing is really at fault, it may be because
they're using a thicker coating than the part can safely accept.
Consider: The anodizing process itself effectively etches the
aluminum, and if they've engineered the part's thickness to be as thin
as possible *before* the process, the anodized part could be just
enough thinner to make a difference. Anodizing which thickens the
part by .002" has scavenged .001" from the metal in the process. One
thousandth of an inch may not seem like much, but if the wheel wall's
thickness is just .020" to begin with, that's a 5% loss of
material...and it's a *uniform* loss from a part which, due to the
shaping and forming of the manufacturing process, most likely *isn't*
of terribly uniform thickness at that point. So, in some places the
loss will be higher than 5%, and in other places it will be lower,
thus aggravating the stress distribution problems that might have been
present. A hardcoated part would typically have a much thicker
coating, and the same 50/50 ratio still applies; a coating of
thickness x scavenges x/2 metal. Additionally, the metal loss would
likely highlight the inherent flaws in the material and accelerate the
failure process. Aluminum oxide has little tensile strength; it would
hardly be able to concentrate strain by its own flexure cracks. (It
has good compression strength, but in this case, the flexing of the
surface is not likely to be in the direction in which that would come
into play.) Instead of focusing the flex stresses, the presence of
those cracks would just be an indicator of where the flexing was
taking place. To get an apples-to-apples comparison, then, it would
be necessary to anodize a wheel that was engineered to have the same
thickness of metal *after* the anodizing process as the other one had
without it.
In other words, I think that you may be right about the reason for the
failures (the anodizing itself), but mistaking the effect (coating
cracks) for the cause (material etching which produces a heightened
degree of stress concentration along existing fold and stretch lines).
Martyn Aldis
jobst....@stanfordalumni.org writes
>> that would be true in the absence of other defects. but as you can
>> see in this pic,
>
>http://technology.open.ac.uk/materials/mem/images/images_cc/ccf3.gif
>
>Your picture is of a machined sidewall, not an extruded form. The
>profile was anodized in the extruded bar condition and is anodized
>inside and out. When forming the hoop, the anodized surface crazes
>being less elastic than the aluminum substrate that is yielding about
I'm interested to know how you can tell that the process took place
before the hoop was formed in this case. On rims with welded joints it
looks like the weld is made and tidied up before the surface finishing
process.
Martyn Aldis, e-mail martyn...@syntagma.co.uk
==============================================================================
David Damerell
>On 17 Aug 2003 12:08:34 -0700, dianne_1234 <diann...@yahoo.com> wrote:
>>Folding?
>Absolutely. How else are you supposed to carry an extra one?
A steel bead tyre rolled into three will fit into even a moderately sized
saddlebag, so unless you abhor luggage that's not a problem.
--
David Damerell <dame...@chiark.greenend.org.uk> Kill the tomato!
Qui si parla Campagnolo
Kinda like 'light, durable and cheap...pick two'...
John Albergo
jim beam wrote:
>
>
> you /do/ see cracks in rim anodizing all the time. on a long enough
> time frame, because aluminum has no fatigue endurance limit, agreed,
> whese could become a problem, but it's not the reason for the rapid
> cracking we saw with the ma40 or the examples above. iirc, the ma40
> was mavic's "maxtal" test rim and they badly screwed up it's extrusion
> processing. mavic still do screw up from time to time, but they're
> not as bad as they used to be.
Weren't ma40 and ma2 produced from the same extrusion?
jobst....@stanfordalumni.org
>>> that would be true in the absence of other defects. but as you can
>>> see in this pic,
http://technology.open.ac.uk/materials/mem/images/images_cc/ccf3.gif
>> Your picture is of a machined sidewall, not an extruded form. The
>> profile was anodized in the extruded bar condition and is anodized
>> inside and out. When forming the hoop, the anodized surface crazes
>> being less elastic than the aluminum substrate that is yielding
>> about
> I'm interested to know how you can tell that the process took place
> before the hoop was formed in this case. On rims with welded joints
> it looks like the weld is made and tidied up before the surface
> finishing process.
You're right, welded joint rims are anodized after forming. I was
thinking of the butt-joint-with-filler-piece rims that were formed
after anodising. That process was probably a reason for more failures
when that was the mainstay than now.
This is an additional expense since rims in the circular form require
more space than extruded bars for the anodizing process. In any case,
the sidewalls are machined to have the "record groove" surface after
anodizing, another intermediate step that makes rims more than twice
as expensive as they need be.
Kraig Willett
http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&oe=UTF-8&q=willett+bulk+o
rder+%2460+along
and my skepticism of alodine usage by mavic "back in the day"
http://groups.google.com/groups?q=willett+alodine&ie=UTF-8&oe=UTF-8&hl=en&bt
nG=Google+Search
--
==================
Kraig Willett
www.biketechreview.com
==================
Martyn Aldis
Willett <kdubent...@adelphia.net.remove> writes
> regarding rim pricing:
Perhaps the move to anodized rims is not just a way of charging more. It
could go with the move to alloys that are stronger (with the appropriate
heat treatment) but are also less corrosion resistant. I think this lack
of corrosion resistance could be the cause of the cracking problems not
the surface finish but I have no solid evidence. I do not have
information on what goes into the modern alloys for a start, let alone
what heat treatment they get.
I've had a go to in this NG to see if anyone has anything to offer on
stress corrosion cracking but it looks like nobody has.
>
>and my skepticism of alodine usage by mavic "back in the day"
>
>http://groups.google.com/groups?q=willett+alodine&ie=UTF-8&oe=UTF-8&hl=en&bt
>nG=Google+Search
>--
Yes alodine is a trade name for a particular conversion coating solution
that has become generalised to mean dip or brush on conversion coatings
in general. Although there are applications where conversion coatings
are used as a final finish, rather than pre-paint, such as electrical
shielding, as you say it does not appear to be an obvious choice for
rims. Perhaps there is a rugged type that Mavic used.
However, isn't this alodine thing a bit of a red herring?
The rims being sold now are anodized and they are said to crack more
than the good old sort. Is the finish the cause?
I've tried Google but I just get the same recycled stuff from this NG
and other bicycle talk. What's needed are some solid references from
materials science.
Martyn Aldis,e-mail martyn...@syntagma.co.uk
==============================================================================
jobst....@stanfordalumni.org
> Perhaps the move to anodized rims is not just a way of charging
> more. It could go with the move to alloys that are stronger (with
> the appropriate heat treatment) but are also less corrosion
> resistant. I think this lack of corrosion resistance could be the
> cause of the cracking problems not the surface finish but I have no
> solid evidence. I do not have information on what goes into the
> modern alloys for a start, let alone what heat treatment they get.
That doesn't make sense because rim failures began as a general plague
with the advent of anodizing and there is no doubt that the rim makers
were totally in the dark about the effects as they showed by their
promotional literature. They emphasized "Hard anodizing" giving the
relative hardness of the coating to aluminum and claiming that it made
stronger stiffer rims. Instead we got spoke pull-outs and
circumferential cracking.
After hefty debate here on wreck.bike the tone gradually changed and
anodizing got thinner. They couldn't just stop doing that because
then it would be an admission of guilt. So now we have occasional
failures and smartly colored rims. Ksyrium being the latest
escalation of expense without function. It has ALL the rave features:
Welded, anodized, sidewall machining, back side relief, and heavy.
> I've had a go to in this NG to see if anyone has anything to offer
> on stress corrosion cracking but it looks like nobody has.
>> and my skepticism of alodine usage by Mavic "back in the day"
>> http://groups.google.com/groups?q=willett+alodine&ie=UTF-8&oe=UTF-8&hl=en&btnG=Google+Search
> Yes alodine is a trade name for a particular conversion coating
> solution that has become generalised to mean dip or brush on
> conversion coatings in general. Although there are applications
> where conversion coatings are used as a final finish, rather than
> pre-paint, such as electrical shielding, as you say it does not
> appear to be an obvious choice for rims. Perhaps there is a rugged
> type that Mavic used.
> However, isn't this alodine thing a bit of a red herring?
Yes of course it is. We've been there before.
> The rims being sold now are anodized and they are said to crack more
> than the good old sort. Is the finish the cause?
Yes and it isn't a change in alloy that causes it. As I explained in
a simple but directly related analogy close to the flesh, bending a
scab on the knee will crack it and cause bleeding while softening it in
water and washing it off will allow even the new pink skin to withstand
the bending stress. A ceramic hard-coat (anodizing) works the same way.
> I've tried Google but I just get the same recycled stuff from this NG
> and other bicycle talk. What's needed are some solid references from
> materials science.
List papers on the subject but does not display them.
http://www.poeton.co.uk/w1/a300.htm
Read under "Mechanical Strength/Fatigue Strength" and find:
"Hard anodising also reduces the fatigue strength of the base material by approximately 47%."
I find that information on the web dodges around the issue and doesn't
even explain what causes the reduction in fatigue endurance if at all.
http://www.ase4anodising.co.uk/Hard.htm
http://www.acorn-nisil.com.au/anodising.html
http://www.hard-anodising.co.uk/tap_ha.asp
http://www.reactivesuspension.com/services.html
http://www.magnesiumcoating.com/w1/default.asp?page=design.htm
jim beam
you never seem bleat about all the other anodized rims from other
manufacturers, but hey, maybe you don't use them. and stop going on
about something that's 10+ years old. you still fly in planes don't
you? there have been countless fatigue failures in that arena. doesn't
give sufficient reason never to fly does it?
2. tell campy to stop anodizing critical components like brake levers
and calipers. and perhaps you'd best talk to your friends at alcoa too.
they're making anodized aluminum truck wheels these days. i'd hate to
have a big rig find it's way into my living room beacuse it had split a rim.
3. aluminum has no fatigue endurance limit. period. the rim is going
to break one way or another. it's simply a matter of when and how. all
a manufacturer is doing is walking the line between something that is
usably light, lasts a reasonably long period if time for in the markets
to which it's sold and makes price point. if a rims doesn't fail
because if it's natural fatigue life, the braking surfaces will wear
out. if it's not that, it'll be a pot-hole. it's all a matter of what
lasts an acceptably long time [i.e. does *not* fall apart at low milage
because there was crud in the extrusion], is light enough for the job,
and doesn't break the bank.
just because you never wear your rims out, never crash, never pot-hole,
never have your bike driven into by cars while it's parked outside the
donut shop, just because you're outside the 3 sigma, is /absolutely no
reason/ for a manufacturer do drop everything and set their
technological clock back 10+ years!
honestly, you just don't want to hear anything/anyone that does not
agree with you, regardless of merit.
jb
David Damerell
>1. jobst, stop using mavic rims. then you can't complain about them.
>you never seem bleat about all the other anodized rims from other
>manufacturers,
This is not true, of course.
>2. tell campy to stop anodizing critical components like brake levers
>and calipers.
I don't know about you, but I don't have spoke eyelets set into _my_ brake
levers...
>3. aluminum has no fatigue endurance limit. period. the rim is going
>to break one way or another. it's simply a matter of when and how. all
>a manufacturer is doing is walking the line between something that is
>usably light, lasts a reasonably long period if time for in the markets
>to which it's sold and makes price point.
Which of these properties do you suppose anodization helps with?
>donut shop, just because you're outside the 3 sigma, is /absolutely no
>reason/ for a manufacturer do drop everything and set their
>technological clock back 10+ years!
Why would abandoning a useless process be setting the clock back?
BTW, for God's sake, find the Shift key!
--
David Damerell <dame...@chiark.greenend.org.uk> Distortion Field!
Stella Hackell
> 1. jobst . . .
>
> just because you never wear your rims out, never crash, never pot-hole,
> never have your bike driven into by cars while it's parked outside the
> donut shop,
Wow, is the annual Jobst-baiting contest starting already?
Stella
Martyn Aldis
Hackell <ste...@lmi.net> writes
normal use is an interesting and legitimate one for a technical group.
Jobst has given some useful links in this thread about anodization and
reduced fatigue life (reduced by up to 47 percent if you anodize but do
not use a suitable sealing process). He does not appear to give much
credit to the technical people at Mavic or other rim makers. They can
read anodization process specifications too and are well qualified to
apply what they mean to the product as they will know what alloys and
treatments they are using. He also has an idea about how the cracks in
anodization could spread into the metal. There have been intelligent
questions raised about limitations to this idea. There is a useful
layman's introduction to crack propagation in the classic book:
The New Science of Strong Materials or Why You Don't Fall Through the
Floor by James Edward Gordon.
http://www.amazon.com/exec/obidos/tg/detail/-/0691023808/qid=1062060018/s
r=1-1/ref=sr_1_1/102-2458197-9842507?v=glance&s=books
I tried in another thread to raise the question of very high strength
alloys and stress corrosion cracking. I think that is interesting
because it does not involve large numbers of stress cycles and may
indicate that high static stress could be part of the problem. (That is
why I suggested Brandt's law of spoke tension could be limited.) I had
an idea some of these rims use 7000 series alloys that are more prone to
corrosion problems than the 6000 series but I now see Mavic say Maxtal
is a 6000 alloy so that may be a dead end. As far as this group goes
that thread disappeared into a discussion of motor industry politics at
once while this thread turned into personal bickering. If anyone who
follows this group actually knows anything about the technical details
of these failures they do not seem to want to show their hand. They may
be right that some views have become so entrenched that no progress will
be made.
Usual newsgroup problems.
Questioning assumptions and asking for justification is not baiting but
I agree that the stuff you quoted is not going to encourage intelligent
debate.
Martyn Aldis e-mail martyn...@syntagma.co.uk
==============================================================================
jobst....@stanfordalumni.org
> I think the question of why some rims crack after fairly modest and
> normal use is an interesting and legitimate one for a technical
> group. Jobst has given some useful links in this thread about
> anodization and reduced fatigue life (reduced by up to 47 percent if
> you anodize but do not use a suitable sealing process). He does not
> appear to give much credit to the technical people at Mavic or other
> rim makers. They can read anodization process specifications too
> and are well qualified to apply what they mean to the product as
> they will know what alloys and treatments they are using. He also
> has an idea about how the cracks in anodization could spread into
> the metal. There have been intelligent questions raised about
> limitations to this idea. There is a useful layman's introduction
> to crack propagation in the classic book:
> The New Science of Strong Materials or Why You Don't Fall Through the
> Floor by James Edward Gordon.
> http://www.amazon.com/exec/obidos/tg/detail/-/0691023808/qid=1062060018/s
> r=1-1/ref=sr_1_1/102-2458197-9842507?v=glance&s=books
What seems overlooked in the assessment of rim cracks is that my book
was written in the days when rims did not crack. Rims made by such
companies as Fiamme, Ambrosio, Mavic, Super Champion, Martano, Nisi,
Scheeren, and others. Wheels were built and tensioned as described in
the book, and lasted until they wore thin from braking or were
crashed. Cracked rims were practically unknown.
From what we have read in this thread, one might get the notion that
skills of extruding aluminum and choosing the alloy were lost at about
the time that Mavic introduce anodizing to rims. Those of us who
consciously witnessed that time, noticed that while great claims of
superior strength through hard anodizing were made rims began cracking
left and right, some cracking circumferentially through the side walls
into the hollow chamber leaving the tire on one half and the spokes in
the other. What's more is that at that time there was a shiny MA-2
and an anodized MA-40 of which only the MA-40 cracked.
Manufacturers weren't entirely blind to this but were not ready to
admit an error. Besides, they did not want to give up the
non-metallic (non-silver) aluminum rim. So now we have colored rims
that are anodized but not hard anodized, which reduces the tendency to
crack but does not get us back to polished rims, something that is
more durable and less expensive than anodizing.
> I tried in another thread to raise the question of very high
> strength alloys and stress corrosion cracking. I think that is
> interesting because it does not involve large numbers of stress
> cycles and may indicate that high static stress could be part of the
> problem. (That is why I suggested Brandt's law of spoke tension
> could be limited.) I had an idea some of these rims use 7000 series
> alloys that are more prone to corrosion problems than the 6000
> series but I now see Mavic say Maxtal is a 6000 alloy so that may be
> a dead end. As far as this group goes that thread disappeared into
> a discussion of motor industry politics at once while this thread
> turned into personal bickering. If anyone who follows this group
> actually knows anything about the technical details of these
> failures they do not seem to want to show their hand. They may be
> right that some views have become so entrenched that no progress
> will be made.
Why should one use an alloy that does not perform as well as a lesser
one in the face of proven reliability of the so called lesser alloy?
I suppose we could investigate stress corrosion and all sorts of other
diversions, but it remains that rims did not crack before all this
"material enhancement" came on the scene.
So what was the secret of all the shiny rims that did not crack in the
days of yore? Are we to believe that today's riders are all heavier
and stronger than those of, say Eddy Merckx's day and that they are
more demanding of their wheels? I don't believe a word of it.
Tom Nakashima
problem" why haven't they gone back to the non-anodized sturdy rims like
Mavic MA-2s?
-tom
<jobst....@stanfordalumni.org> wrote in message
news:ymq3b.16146$dk4.5...@typhoon.sonic.net...
jim beam
> skills of extruding aluminum and choosing the alloy were lost at about
> the time that Mavic introduce anodizing to rims.
now /that's/ a good point.
> Why should one use an alloy that does not perform as well as a lesser
> one in the face of proven reliability of the so called lesser alloy?
so is that.
> I suppose we could investigate stress corrosion and all sorts of other
> diversions, but it remains that rims did not crack before all this
> "material enhancement" came on the scene.
i think a lot of it, as you have rightly pointed out in the past, is
manufacturers knowing that the market [tacitly] supports "inferior" product.
there are two things in my view that are relevant:
1. anodizing /is/ beneficial for the majority of the market. not so
much here in california, but in places where it rains a lot, unanodized
rims can stain & pit badly if they're not wiped off after every wet ride.
2. modern alloys are slightly better than the older in terms of yield
strength. for a wheel that's expertly built, the older alloys were [and
still are] absolutely fine. but if you have a mediocre/bad wheel
builder [the majority of the market it seems] and one hoop has say 5%
better yield than before, it's going to be a little bit truer for a
little bit longer. long enough to survive the test ride and make the
sale at any rate, and that's important!
we can argue that "the old days were better" endlessly, and it's good to
point out that manufacurers screw up, but it's not /all/ evil. i
inherited an old cut-throat razor a while back. the steel is quite
superb and it takes an edge like you wouldn't believe! but the fact
still remains that i much prefer a modern disposable because it /keeps/
its edge and is instantly ready to go. and yes, i have to replace them
all the time and have doubtless spent considerably more on disposables
than i ever would have on a quality cut-throat, but the advantages of
one out-weigh the other.
in my view, that's exactly the situation we have with rims.
j
Tim McNamara
jim beam <u...@ftc.gov> wrote:
> 1. anodizing /is/ beneficial for the majority of the market. not
> so much here in california, but in places where it rains a lot,
> unanodized rims can stain & pit badly if they're not wiped off
> after every wet ride.
Rains here in Minnesota. My MA2s never pit or stain. But on the
other hand, the potholes and crappy road surfaces we contend with
limit the life span of rims.
jim beam
me right now, but i have a mavic catalog with the ma2 range on it.
iirc, there are 5 variants including "bright" and "silver anodized" as
well as the colored anodized. i even have a silver anodized one myself.
jb