Aerohead rim cracking

Hi

I recently bought a front wheel with a radially-laced, straight-pull 24h Aerohead rim on ebay, and
when it arrived, to my dismay, there were hairline cracks in the anodized layer - perhaps the rim
itself? - on at least one side of every spoke hole on the rim.

The seller has kindly offered compensation, but in order to reach agreement we agree on how
extensive it should be, he asked me to get a second opinion. So here I humbly seek all your second
opinions. If you have some time, check out the link below:

http://www.stanford.edu/~weisong/aerohead.htm

The wheel itself is very true, no hops, does not appear to have been abused. If you're an
experienced aerohead user or experienced with heat-treated rims in general, please tell me whether
this damage is strictly cosmetic, or is an omen of catastrophic things to come.

Note: blue Aerohead rims are supposed to be powder-coated, but this seems to be an older model and
sure looks like anodiztion to me. But perhaps you can tell?

thanks Song

Song wrote:

> Hi
>
> I recently bought a front wheel with a radially-laced, straight-pull 24h Aerohead rim on ebay, and
> when it arrived, to my dismay, there were hairline cracks in the anodized layer - perhaps the rim
> itself? - on at least one side of every spoke hole on the rim.
>
> The seller has kindly offered compensation, but in order to reach agreement we agree on how
> extensive it should be, he asked me to get a second opinion. So here I humbly seek all your second
> opinions. If you have some time, check out the link below:
>
> http://www.stanford.edu/~weisong/aerohead.htm
>
> The wheel itself is very true, no hops, does not appear to have been abused. If you're an
> experienced aerohead user or experienced with heat-treated rims in general, please tell me whether
> this damage is strictly cosmetic, or is an omen of catastrophic things to come.
>
> Note: blue Aerohead rims are supposed to be powder-coated, but this seems to be an older model and
> sure looks like anodiztion to me. But perhaps you can tell?

The sheen looks like anodising to me too. However, IME this type of anodising doesn't usually cause
a problem compared to the hard black stuff. Probably the rim is just underweight and underspecified
for this many spokes and this much spoke tension. In other words, it's a lemon.

On Sun, 15 Feb 2004 10:26:05 -0800, "Song" <weisong@stanford.edu>
wrote:

>Hi
>
>I recently bought a front wheel with a radially-laced, straight-pull 24h Aerohead rim on ebay, and
>when it arrived, to my dismay, there were hairline cracks in the anodized layer - perhaps the rim
>itself? - on at least one side of every spoke hole on the rim.
>
>The seller has kindly offered compensation, but in order to reach agreement we agree on how
>extensive it should be, he asked me to get a second opinion. So here I humbly seek all your second
>opinions. If you have some time, check out the link below:
>
>http://www.stanford.edu/~weisong/aerohead.htm
>
>The wheel itself is very true, no hops, does not appear to have been abused. If you're an
>experienced aerohead user or experienced with heat-treated rims in general, please tell me whether
>this damage is strictly cosmetic, or is an omen of catastrophic things to come.
>
>Note: blue Aerohead rims are supposed to be powder-coated, but this seems to be an older model and
> sure looks like anodiztion to me. But perhaps you can tell?
>
>thanks Song
>

All the Aeroheads I've seen have these cracks after a few weeks. In my experience they stop growing
and remain no problem for a long, long time (many years).

Yes, that blue looks anodized to me too. I wouldn't worry about it.

what's your spoke tension?

Song wrote:
> Hi
>
> I recently bought a front wheel with a radially-laced, straight-pull 24h Aerohead rim on ebay, and
> when it arrived, to my dismay, there were hairline cracks in the anodized layer - perhaps the rim
> itself? - on at least one side of every spoke hole on the rim.
>
> The seller has kindly offered compensation, but in order to reach agreement we agree on how
> extensive it should be, he asked me to get a second opinion. So here I humbly seek all your second
> opinions. If you have some time, check out the link below:
>
> http://www.stanford.edu/~weisong/aerohead.htm
>
> The wheel itself is very true, no hops, does not appear to have been abused. If you're an
> experienced aerohead user or experienced with heat-treated rims in general, please tell me whether
> this damage is strictly cosmetic, or is an omen of catastrophic things to come.
>
> Note: blue Aerohead rims are supposed to be powder-coated, but this seems to be an older model and
> sure looks like anodiztion to me. But perhaps you can tell?
>
> thanks Song

Well, radial spoking and 24 spokes doesn't start off on the best feet. Radial spoking is harder on hubs, spokes, and rims.
I have used Velocity Aeorhead rims down to 28 spokes with 2X spoking for fronts with no cracks after over 20,000 miles. I have also had very good results with their OCR 32 hole rim spoked 3X with DT Competition DB spokes for rears.
I use their powder coated rims.
I would call and ask Velocity USA their opinion. They are in Michigan. Phone616)243.3400
velocity@velocityusa.com
They may not be very interested in an eBay deal that is sour.

__________________
David Ornee, Western Springs, IL USA

On Sun, 15 Feb 2004 21:58:23 GMT, jim beam <uce@ftc.gov> wrote:

>Song wrote:
>> ...Aerohead rim ... hairline cracks ... on at least one side of every spoke hole on the rim.

>what's your spoke tension?
>

The Velocity Aerohead is an unusual rim. The space inside is slightly smaller than the width of many
common spoke nipples. So as the spokes are tensioned the nipple head acts like a wedge and puts high
lateral force on the inside rim wall. This often leads to deformation and almost always to very
early cracking, aided by the knife edge where the side of the spoke hole cuts through the thin side
wall of the rim.

So while excessive spoke tension in ordinary rims hastens cracking, in this rim merely assembling it
into a reasonable wheel hastens rim cracking.

But as I noted in another post, the cracks, once formed, take a very long time to grow beyond a few
millimeters. Speculating here, but maybe the nipple head wedges deeper and comes to rest against the
thick wall in nose of the rim?

I think Velocity might have redesigned the Aerohead rim since this one was made.

dianne_1234 <dianne_1234@NOSPAMyahoo.com> wrote in message news:<p6hv201t1ss8qck5k1n5q1bm4leddbbr46@4ax.com>...

>
>
> All the Aeroheads I've seen have these cracks after a few weeks. In my experience they stop
> growing and remain no problem for a long, long time (many years).
>
> Yes, that blue looks anodized to me too. I wouldn't worry about it.

Hi, are you talking about Velocity brand aerohead rims? If so, is this still a problem? And do they
have the same problem withe Deep V?

Any info will be appreciated. Jeff

jim beam <uce@ftc.gov> writes:

> what's your spoke tension?

What does it matter? This question is irrelevant.

It's clear from the photos, the rim is a goner and should be replaced. There is no such thing as a
"cosmetic" crack in an anodized rim, as the crack *will* propogate into the base metal and the rim
will fail.

> The Velocity Aerohead is an unusual rim. The space inside is slightly smaller than the width of
> many common spoke nipples. So as the spokes are tensioned the nipple head acts like a wedge and
> puts high lateral force on the inside rim wall.

I thought that is why it's recommended to use nipple washers on these rims.

"dianne_1234" <dianne_1234@NOSPAMyahoo.com> wrote in message
news:gkvv20lf9u4umph8iagbdbuk75hbn4dcs8@4ax.com...
> On Sun, 15 Feb 2004 21:58:23 GMT, jim beam <uce@ftc.gov> wrote:
>
> >Song wrote:
> >> ...Aerohead rim ... hairline cracks ... on at least one side of every spoke hole on the rim.
>
> >what's your spoke tension?
> >
>
> The Velocity Aerohead is an unusual rim. The space inside is slightly smaller than the width of
> many common spoke nipples. So as the spokes are tensioned the nipple head acts like a wedge and
> puts high lateral force on the inside rim wall. This often leads to deformation and almost always
> to very early cracking, aided by the knife edge where the side of the spoke hole cuts through the
> thin side wall of the rim.
>
> So while excessive spoke tension in ordinary rims hastens cracking, in this rim merely assembling
> it into a reasonable wheel hastens rim cracking.
>
> But as I noted in another post, the cracks, once formed, take a very long time to grow beyond a
> few millimeters. Speculating here, but maybe the nipple head wedges deeper and comes to rest
> against the thick wall in nose of the rim?
>
> I think Velocity might have redesigned the Aerohead rim since this one was made.

On Sun, 15 Feb 2004 10:26:05 -0800, "Song" <weisong@stanford.edu> may
have said:

>Hi
>
>I recently bought a front wheel with a radially-laced, straight-pull 24h Aerohead rim on ebay, and
>when it arrived, to my dismay, there were hairline cracks in the anodized layer - perhaps the rim
>itself? - on at least one side of every spoke hole on the rim.
>
>The seller has kindly offered compensation, but in order to reach agreement we agree on how
>extensive it should be, he asked me to get a second opinion. So here I humbly seek all your second
>opinions. If you have some time, check out the link below:
>
>http://www.stanford.edu/~weisong/aerohead.htm

Anodizing is very brittle. It will crack easily when the underlying metal deforms. I'd only be
seriously worried myself if the crack actually goes through the metal. You may be able to determine
if this is the case by taling a couple of spokes out and examining the nipple hole with a magnifier.
A dye-check of the area would probably be misleading, unfortunately. If you can confirm that the
crack extends through, I would be underwhelmed with the concept of putting this rim into service. If
the cracks are in the anodization only, I'd say it's purely a judgement call. I'm not sure which way
I'd jump in that case.

Another poster's suggestion to call the manufacturer and ask about the issue seems well-founded.

--
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.
Words processed in a facility that contains nuts.

"Song" <weisong@stanford.edu> wrote in message news:<c0odl8$ge0$1@news.Stanford.EDU>...
> Hi
>
> I recently bought a front wheel with a radially-laced, straight-pull 24h Aerohead rim on ebay, and
> when it arrived, to my dismay, there were hairline cracks in the anodized layer - perhaps the rim
> itself? - on at least one side of every spoke hole on the rim.
>
> The seller has kindly offered compensation, but in order to reach agreement we agree on how
> extensive it should be, he asked me to get a second opinion. So here I humbly seek all your second
> opinions. If you have some time, check out the link below:
>
> http://www.stanford.edu/~weisong/aerohead.htm
>
> The wheel itself is very true, no hops, does not appear to have been abused. If you're an
> experienced aerohead user or experienced with heat-treated rims in general, please tell me whether
> this damage is strictly cosmetic, or is an omen of catastrophic things to come.
>
> Note: blue Aerohead rims are supposed to be powder-coated, but this seems to be an older model and
> sure looks like anodiztion to me. But perhaps you can tell?
>
> thanks Song

I have the old American Classic wheels built on Velocity Aero heads. Same issue with the micro-
cracks on the rear wheel. My Radial front has no signs of cracking. I replaced my rear with a CXP21
rim. The wheel is shot.

-a

On Sun, 15 Feb 2004 18:50:33 -0600, Tim McNamara
<timmcn@bitstream.net> wrote:

>jim beam <uce@ftc.gov> writes:
>
>> what's your spoke tension?
>
>What does it matter? This question is irrelevant.

In most rims higher tension leads to earlier fatigue cracking. Modified Goodman curve, etc.

>It's clear from the photos, the rim is a goner and should be replaced. There is no such thing as a
>"cosmetic" crack in an anodized rim, as the crack *will* propogate into the base metal and the rim
>will fail.

In my experience, this rim (Velocity Aerohead) has been durable with cracks exactly like the ones in
the photo. I think this might be so because I imagine the stress might decrease for two reasons:
1. the wall gets thicker away from the edge of the spoke hole, and
2. the spoke nipple comes to rest on the inside of the rim.

Even if my guesses 1 and 2 are wrong, my experience is still real.

Wei Song writes:

> I recently bought a front wheel with a radially-laced, straight-pull 24h Aerohead rim on eBay,
> and when it arrived, to my dismay, there were hairline cracks in the anodized layer - perhaps the
> rim itself?
> - on at least one side of every spoke hole on the rim.

> The seller has kindly offered compensation, but in order to reach agreement we agree on how
> extensive it should be, he asked me to get a second opinion. So here I humbly seek all your second
> opinions. If you have some time, check out the link below:

http://www.stanford.edu/~weisong/aerohead.htm

> The wheel itself is very true, no hops, does not appear to have been abused. If you're an
> experienced Aerohead user or experienced with heat-treated rims in general, please tell me whether
> this damage is strictly cosmetic, or is an omen of catastrophic things to come.

> Note: blue Aerohead rims are supposed to be powder-coated, but this seems to be an older model and
> sure looks like anodiztion to me. But perhaps you can tell?

This rim is anodized and the crack is IN the aluminum, anodized coatings seldom being more than
0.001" thick. This problem cannot be solved with washers, there being no space to fit a washer
inside this rim. It is possible that the inside of the rim has a counterbore that is too small for
the spoke nipple head and that it has wedged itself into a splitting position but that doesn't hold
much hope because such a nipple could not be readily turned to tension spokes. Therefore, I believe
the cracks are on the way to getting larger with use.

One should wonder why sockets and eyelets were used with success on 300g rims of old. The claim is
that we have better materials today but the cracks don't support that claim.

Jobst Brandt jobst.brandt@stanfordalumni.org

On Tue, 17 Feb 2004 05:35:59 GMT, jobst.brandt@stanfordalumni.org may
have said:

>One should wonder why sockets and eyelets were used with success on 300g rims of old. The claim is
>that we have better materials today but the cracks don't support that claim.

I have no doubt the answer to that is simple: profit.

(Not that the presence of eyelets and sockets alone will keep certain vexatious rims from
cracking...)

--
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Typoes are not a bug, they're a feature.
Words processed in a facility that contains nuts.

> Wei Song writes:
>
>
>>I recently bought a front wheel with a radially-laced, straight-pull 24h Aerohead rim on eBay, and
>>when it arrived, to my dismay, there were hairline cracks in the anodized layer
-snip-
>>The seller has kindly offered compensation
-snip-
> http://www.stanford.edu/~weisong/aerohead.htm
-snip-
>>Note: blue Aerohead rims are supposed to be powder-coated, but this seems to be an older model and
>> sure looks like anodiztion to me. But perhaps you can tell?

jobst.brandt@stanfordalumni.org wrote:
> This rim is anodized and the crack is IN the aluminum, anodized coatings seldom being more than
> 0.001" thick. This problem cannot be solved with washers, there being no space to fit a washer
> inside this rim. It is possible that the inside of the rim has a counterbore that is too small for
> the spoke nipple head and that it has wedged itself into a splitting position but that doesn't
> hold much hope because such a nipple could not be readily turned to tension spokes. Therefore, I
> believe the cracks are on the way to getting larger with use.
>
> One should wonder why sockets and eyelets were used with success on 300g rims of old. The claim is
> that we have better materials today but the cracks don't support that claim.
>
> Jobst Brandt jobst.brandt@stanfordalumni.org

I'm pretty sure that's the older discontinueed Aerohead. It got a cross-section change a couple of
years ago and is now offered without cut sides in silver or black anodize finish. Colors are painted
with cut sides

I'm with Jobst - return this wheel.

--
Andrew Muzi www.yellowjersey.org Open every day since 1 April, 1971