black anodized hubs bad?

I've heard about anodized rims being more prone to failure, but what about hubs? Are black anodized
hubs more prone to spoke ripout or other failures?

-Eric B

 

> I've heard about anodized rims being more prone to failure, but what about hubs? Are black
> anodized hubs more prone to spoke ripout or other failures?

WTF? where did you hear this shit? I've never heard anything like that in my life, and I work at a
LBS. I've seen plenty of anodized bike componentry, I even run blue anodized Hope Big 'un hubs.
They're the strongest things I've ever bought for my bike. one year and some insane riding later,
they're not showing any signs of stressing or cracking round the eyelets. I think you just picked up
on some urban myth.

Small Black Dog

 

Small Black Dog wrote:
>>I've heard about anodized rims being more prone to failure, but what about hubs? Are black
>>anodized hubs more prone to spoke ripout or other failures?
>
>
> WTF? where did you hear this shit? I've never heard anything like that in my life, and I work at a
> LBS. I've seen plenty of anodized bike componentry, I even run blue anodized Hope Big 'un hubs.
> They're the strongest things I've ever bought for my bike. one year and some insane riding later,
> they're not showing any signs of stressing or cracking round the eyelets. I think you just picked
> up on some urban myth.
>
> Small Black Dog
>

Gee, you haven't been reading the group (or maybe it's alt.mountain-bike). Many have had problems
with black anodized rims stress cracking. Do a google search. Check MTBR for black Mavic rims.

I know that my problems were news to my LBS, but they also told me that I probably ride the most and
the hardest of their customers. They now hesitate to sell me anything that's light because I just
break it .

David

 

> Gee, you haven't been reading the group (or maybe it's alt.mountain-bike). Many have had problems
> with black anodized rims stress cracking. Do a google search. Check MTBR for black Mavic rims.
>
> I know that my problems were news to my LBS, but they also told me that I probably ride the most
> and the hardest of their customers. They now hesitate to sell me anything that's light because I
> just break it .

Surely thats just a problem with the quality of the rim, not the anodizing process? I wouldnt have
thought anodizing something would fck it up so much. I've heard of the lighter, more XC style mavic
rims being weak at the eyelets. My Dad owns the X517s which I think are one of the problematic
models. I havent noticed any stressing or cracks ... yet

Small Black Dog

 

On 18 Apr 2003 23:13:19 -0700, [email protected] (eric bazan) wrote:

>I've heard about anodized rims being more prone to failure, but what about hubs? Are black anodized
>hubs more prone to spoke ripout or other failures?

Its not the black ano that is the major problem, its the hard-ano that is prone to cracking more.
(the dark murky stuff, mavic calls it CD)

In my experience, the only rims I have had that developed cracks at the eyeleets were silver ano
(mavic 238) and a Matrix swami one.

Have some valiants, mustangs and 223's that so far are crack free.

G

 

> Its not the black ano that is the major problem, its the hard-ano that is prone to cracking more.
> (the dark murky stuff, mavic calls it CD)

The term they like to use is "Ceramic"

> In my experience, the only rims I have had that developed cracks at the eyeleets were silver ano
> (mavic 238) and a Matrix swami one.

The Mavic 238s are about 5 years old, manufacturing has (i hope) improved since then.

I run Mavic D321 Discs which are the best rims I've used to date. After almost 2 years of riding
they're still not showing any stresses. My friend bought my old Mavic D521 CDs (with the "Ceramic"
coating) from me when I upgraded to discs. They've been rolling for even longer, and again, no sign
of cracks or stressing.

Small Black Dog

 

Small Black Dog wrote:
>> I've heard about anodized rims being more prone to failure, but what about hubs? Are black
>> anodized hubs more prone to spoke ripout or other failures?
>
> WTF? where did you hear this shit?

Read this: http://draco.acs.uci.edu/rbfaq/FAQ/8c.2.html

Personally, I'm not sure how much of a difference they really make, but one thing I do know for sure
is that the only rim that I've ever had completely break apart was an MA40: a hard anodized model.

> I've never heard anything like that in my life, and I work at a LBS.

No wonder I avoid bike shops. Most know FA.

~PB

 

"Small Black Dog" <[email protected]> wrote in message
news:[email protected]...
>
> > Its not the black ano that is the major problem, its the hard-ano that is prone to cracking
> > more. (the dark murky stuff, mavic calls it CD)
>
> The term they like to use is "Ceramic"

>
> Small Black Dog

You work in a bike shop? CD rims are the hard anodized ones. Ceramic rims are CD with a ceramic
coating on the brake surface. Check out Jobst Brandt's posts via a Google search on hard anodizing
for details on the cracking issue.

Tim

 

> No wonder I avoid bike shops. Most know FA.

Customers know even less it all works out in the end.

Small Black Dog

 

> You work in a bike shop? CD rims are the hard anodized ones. Ceramic
rims
> are CD with a ceramic coating on the brake surface. Check out Jobst Brandt's posts via a Google
> search on hard anodizing for details on the cracking issue.
>
> Tim

Doh. Thats all I can say for not knowing there was infact a difference between the two.

Small Black Dog

 

Small Black Dog wrote:
>>I've heard about anodized rims being more prone to failure, but what about hubs? Are black
>>anodized hubs more prone to spoke ripout or other failures?
>
>
> WTF? where did you hear this shit? I've never heard anything like that in my life, and I work at a
> LBS. I've seen plenty of anodized bike componentry, I even run blue anodized Hope Big 'un hubs.
> They're the strongest things I've ever bought for my bike. one year and some insane riding later,
> they're not showing any signs of stressing or cracking round the eyelets. I think you just picked
> up on some urban myth.
>
> Small Black Dog

dude, I'd wait a little longer after 4:20 before you post next time

Jon Bond

 

Small Black Dog wrote:

>> No wonder I avoid bike shops. Most know FA.
>
> Customers know even less it all works out in the end.

Most do, yeah, but not the ones reading this newsgroup

~PB

 

Small Black Dog wrote:
>>Gee, you haven't been reading the group (or maybe it's alt.mountain-bike). Many have had problems
>>with black anodized rims stress cracking. Do a google search. Check MTBR for black Mavic rims.
>>
>>I know that my problems were news to my LBS, but they also told me that I probably ride the most
>>and the hardest of their customers. They now hesitate to sell me anything that's light because I
>>just break it .
>
>
> Surely thats just a problem with the quality of the rim, not the anodizing process? I wouldnt have
> thought anodizing something would fck it up so much. I've heard of the lighter, more XC style
> mavic rims being weak at the eyelets. My Dad owns the X517s which I think are one of the
> problematic models. I havent noticed any stressing or cracks ... yet
>
> Small Black Dog
>

Mavic XC rims. x519 -- supposed to be strong. (Also 223, and x219). All black anodized. I don't KNOW
it's the anodization, but I've been told that it's likely.

David

 

i'm new to this group, and i'm amazed at some of the misconceptions about rim cracking. a story gets
repeated frequently does not make it truthful.

yes, some cracks can be caused by fatigue, and yes, some fatigue cracks can be caused by cracked
anodizing. but by far the most common cause of failure is defective extrusions from which the
rim is made.

example: http://technology.open.ac.uk/materials/mem/mem-ccf-rims.html

this is /not/ an anodizing failure.

nor is this: http://tandem-fahren.de/Mitglieder/Christoph_Timm/imm032a.jpg

so, to answer your question about hubs, go ahead and enjoy whatever color you want. theoretically,
they will fatigue eventually, but i seriously doubt you'll /ever/ be able to discern the difference
between a hub that's clear anodized, and one where the anodizing has been dyed.

jim

ps. if you /really/ want to see how fatigue cracks start, read this:
http://rugth30.phys.rug.nl/msc_micromat/fatigue_crack.htm

eric bazan wrote:
> I've heard about anodized rims being more prone to failure, but what about hubs? Are black
> anodized hubs more prone to spoke ripout or other failures?
>
> -Eric B

 

Anodizing is a controlled oxidation of the surface of the aluminum (.001"-.002" for standard,
.003"-.005" thick for "hard"). It is primarily for scratch resistance (Al O is very scratch
resistant, same as corundum, ruby or sapphire). But it offers or detract's almost nothing
structurally, that is just hype to sell components at a higher price.

The color is a dye added to the anodizing bath. Plain anodizing is clear (silver).

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

 

> >> No wonder I avoid bike shops. Most know FA.
> >
> > Customers know even less it all works out in the end.
>
> Most do, yeah, but not the ones reading this newsgroup

Damn, gonna have to think a bit more before I post then, eh?

Small Black Dog

 

>yes, some cracks can be caused by fatigue, and yes, some fatigue cracks can be caused by cracked
>anodizing. but by far the most common cause of failure is defective extrusions from which the
>rim is made.

I think most of us have had anodized rims fail at the spoke hole, I dont think that an
extrusion defect.

Also, the example that is a "rim extrusion defect" looks like a rim with severe brake wear and the
sidewall was just too thin.

Jon Isaacs

 

Mark McMaster wrote:

> But, it should also be kept in mind that the cracks form from fatigue, and fatigue only occurs in
> tension.

That's true for rims (fatigue failure caused by tension), but not for bearings (fatigue failure
caused by surface compression). Most, but not all, fatigue failure is caused by cyclic tension.
--
terry morse Palo Alto, CA http://www.terrymorse.com/bike/

 

Terry Morse wrote:
> Mark McMaster wrote:
>
>
>>But, it should also be kept in mind that the cracks form from fatigue, and fatigue only occurs in
>>tension.
>
>
> That's true for rims (fatigue failure caused by tension), but not for bearings (fatigue failure
> caused by surface compression).

Are you sure? Contact stresses with rolling elements can produce larger shear stresses under the
surface of the race. A shear stress has components of both tension and compression.

Mark McMaster [email protected]

 

Mark McMaster wrote:

> Terry Morse wrote:
> >
> > That's true for rims (fatigue failure caused by tension), but not for bearings (fatigue failure
> > caused by surface compression).
>
> Are you sure? Contact stresses with rolling elements can produce larger shear stresses under the
> surface of the race. A shear stress has components of both tension and compression.

Um, well...okay. A bearing race fatigues from shear (I was thinking more of the external compression
force than the internal shear stresses).
--
terry morse Palo Alto, CA http://www.terrymorse.com/bike/