New wheelset or just rims?



Originally posted by Jobst Brandt
Donald Gillies writes:

>> The Mavic 517's on my beloved Marin Team Issue won't stay
>> true anymore and the LBS says they are ready to go.

Well that's basically BS unless they showed you cracks or
kinks from crashing.

[snip]

Jobst Brandt [email protected]

Dear Jobst,

I was puzzled, too, until I read the original poster's
later explanation of the problem elsewhere in this
somewhat convoluted thread:

> The current rims are bulging where the spokes enter. The
> mechanic says more will start to bulge and then some of the
> spokes will start to pop out.
>
> KP

Carl Fogel
 
Carl Fogel writes:

>>> The Mavic 517's on my beloved Marin Team Issue won't
>>> stay true anymore and the LBS says they are ready to go.

>> Well that's basically BS unless they showed you cracks or
>> kinks from crashing.

> I was puzzled, too, until I read the original poster's
> later explanation of the problem elsewhere in this
> somewhat convoluted thread:

>>>> The current rims are bulging where the spokes enter.
>>>> The mechanic says more will start to bulge and then
>>>> some of the spokes will start to pop out.

That doesn't explain much. As has often been shown and
written about, dark anodized rims often show uneven
coloration on the brake surfaces from bulging at spoke
locations. I'm not sure that these rims have a problem from
what has been explained.

Jobst Brandt [email protected]
 
[email protected] wrote in message news:<[email protected]>...
> Carl Fogel writes:
>
> >>> The Mavic 517's on my beloved Marin Team Issue
> >>> won't stay true anymore and the LBS says they are
> >>> ready to go.
>
> >> Well that's basically BS unless they showed you cracks
> >> or kinks from crashing.
>
> > I was puzzled, too, until I read the original poster's
> > later explanation of the problem elsewhere in this
> > somewhat convoluted thread:
>
> >>>> The current rims are bulging where the spokes enter.
> >>>> The mechanic says more will start to bulge and then
> >>>> some of the spokes will start to pop out.
>
> That doesn't explain much. As has often been shown and
> written about, dark anodized rims often show uneven
> coloration on the brake surfaces from bulging at spoke
> locations. I'm not sure that these rims have a problem
> from what has been explained.
>
> Jobst Brandt [email protected]

Dear Jobst,

Ah, I see what you mean--cosmetic wear on the brake surface
on either side of the nipples, which wouldn't explain the
continuing truing problem.

I thought that the description meant that the rim was
bulging around the nipples themselves "where the
spokes enter" as it failed, which would explain its
going out of true.

Carl Fogel
 
Ken Prager <[email protected]> wrote in message news:<[email protected]>...
> The Mavic 517's on my beloved Marin Team Issue won't stay
> true anymore and the LBS says they are ready to go. One
> mechanic says to just use the old hubs (circa 1998 XTR)
> and another says buy a new wheelset.
>
> I'd appreciate it is some of you could offer advice. Also,
> opinions on rims/wheelsets are also welcome. (I'm 5'9",
> 145 lbs.)
>
> Thanks in advance,
>
> Ken P.

Dear Ken,

I may have mis-read your later explanation that your rim is
bulging where the spokes enter.

Is your rim bulging around the nipples themselves, as if the
spokes are pulling the metal toward the hub?

Or do you mean that the brake surfaces appear to be bulging
sideways on either side of the rim, with the bulges
coinciding with the spokes?

Carl Fogel
 
In article <[email protected]>,
[email protected] (Carl Fogel) wrote:

> Ken Prager <[email protected]> wrote in message
> news:<[email protected]>...
> > The Mavic 517's on my beloved Marin Team Issue won't
> > stay true anymore and the LBS says they are ready to go.
> > One mechanic says to just use the old hubs (circa 1998
> > XTR) and another says buy a new wheelset.
> >
> > I'd appreciate it is some of you could offer advice.
> > Also, opinions on rims/wheelsets are also welcome. (I'm
> > 5'9", 145 lbs.)
> >
> > Thanks in advance,
> >
> > Ken P.
>
> Dear Ken,
>
> I may have mis-read your later explanation that your rim
> is bulging where the spokes enter.
>
> Is your rim bulging around the nipples themselves, as if
> the spokes are pulling the metal toward the hub?

Yes. Slight bulge coupled with whitish discoloration.

> Or do you mean that the brake surfaces appear to be
> bulging sideways on either side of the rim, with the
> bulges coinciding with the spokes?

No.

Also, what I meant in the OP by "won't stay true" is that
they become wobbly again after one ride (with some mild
rocks, drops and bumps--but nothing that anyone would
consider extreme).

TIA,

Ken P.

--
Remove _me_ for e-mail address
 
Ken Prager <[email protected]> wrote in message news:<[email protected]>...
> In article
> <[email protected]>,
> [email protected] (Carl Fogel) wrote:
>
> > Ken Prager <[email protected]> wrote in message
> > news:<[email protected]>...
> > > The Mavic 517's on my beloved Marin Team Issue won't
> > > stay true anymore and the LBS says they are ready to
> > > go. One mechanic says to just use the old hubs (circa
> > > 1998 XTR) and another says buy a new wheelset.
> > >
> > > I'd appreciate it is some of you could offer advice.
> > > Also, opinions on rims/wheelsets are also welcome.
> > > (I'm 5'9", 145 lbs.)
> > >
> > > Thanks in advance,
> > >
> > > Ken P.
> >
> > Dear Ken,
> >
> > I may have mis-read your later explanation that your rim
> > is bulging where the spokes enter.
> >
> > Is your rim bulging around the nipples themselves, as if
> > the spokes are pulling the metal toward the hub?
>
> Yes. Slight bulge coupled with whitish discoloration.
>
>
> > Or do you mean that the brake surfaces appear to be
> > bulging sideways on either side of the rim, with the
> > bulges coinciding with the spokes?
>
> No.
>
>
> Also, what I meant in the OP by "won't stay true" is that
> they become wobbly again after one ride (with some mild
> rocks, drops and bumps--but nothing that anyone would
> consider extreme).
>
> TIA,
>
> Ken P.

Dear Ken,

It sounds as if your rims are hopelessly ruined.

With each round of truing and riding, the spokes are pulling
further through the rim, so you end up re-tensioning them,
and they just pull through again after a few miles.

I expect that most of the well-meant advice that you
received assumed either that there was no such damage or
that you meant a strobe-like wear pattern on the brake
surfaces on either side of the spoke.

Your mechanic would have seen the hideous bulging instantly,
unlike the rest of us theorizing at keyboards.

To be fair, I think that usually the rim actually cracks
around the spoke instead of bulging. The whitish
discoloration is likely corrosion. If you haven't already
peeked under the rim tape, you might do so and see if
there's lots of hidden corrosion.

The hubs are probably fine, so your decision is whether to
buy a whole new wheel set or to build them using your old
spokes, hub, and so forth.

Sorry about your troubles.

Carl Fogel
 
In article <[email protected]>,
[email protected] (Carl Fogel) wrote:

> Ken Prager <[email protected]> wrote in message
> news:<[email protected]>...
> > In article
> > <[email protected]>,
> > [email protected] (Carl Fogel) wrote:
> >
> > > Ken Prager <[email protected]> wrote in message
> > > news:<[email protected]>...
> > > > The Mavic 517's on my beloved Marin Team Issue won't
> > > > stay true anymore and the LBS says they are ready to
> > > > go. One mechanic says to just use the old hubs
> > > > (circa 1998 XTR) and another says buy a new
> > > > wheelset.
> > > >
> > > > I'd appreciate it is some of you could offer advice.
> > > > Also, opinions on rims/wheelsets are also welcome.
> > > > (I'm 5'9", 145 lbs.)
> > > >
> > > > Thanks in advance,
> > > >
> > > > Ken P.
> > >
> > > Dear Ken,
> > >
> > > I may have mis-read your later explanation that your
> > > rim is bulging where the spokes enter.
> > >
> > > Is your rim bulging around the nipples themselves, as
> > > if the spokes are pulling the metal toward the hub?
> >
> > Yes. Slight bulge coupled with whitish discoloration.
> >
> >
> > > Or do you mean that the brake surfaces appear to be
> > > bulging sideways on either side of the rim, with the
> > > bulges coinciding with the spokes?
> >
> > No.
> >
> >
> > Also, what I meant in the OP by "won't stay true" is
> > that they become wobbly again after one ride (with some
> > mild rocks, drops and bumps--but nothing that anyone
> > would consider extreme).
> >
> > TIA,
> >
> > Ken P.
>
> Dear Ken,
>
> It sounds as if your rims are hopelessly ruined.
>
> With each round of truing and riding, the spokes are
> pulling further through the rim, so you end up re-
> tensioning them, and they just pull through again after a
> few miles.
>
> I expect that most of the well-meant advice that you
> received assumed either that there was no such damage or
> that you meant a strobe-like wear pattern on the brake
> surfaces on either side of the spoke.
>
> Your mechanic would have seen the hideous bulging
> instantly, unlike the rest of us theorizing at keyboards.
>
> To be fair, I think that usually the rim actually cracks
> around the spoke instead of bulging. The whitish
> discoloration is likely corrosion. If you haven't already
> peeked under the rim tape, you might do so and see if
> there's lots of hidden corrosion.
>
> The hubs are probably fine, so your decision is whether to
> buy a whole new wheel set or to build them using your old
> spokes, hub, and so forth.
>
> Sorry about your troubles.

Yes, that is my situation. However, after reading all of the
advice and comments, I decided to keep my hubs and ordered a
new pair of Mavic 717 rims.

Thanks,

Ken P.

--
Remove _me_ for e-mail address
 
[email protected] writes:

>Donald Gillies writes:

>>> The Mavic 517's on my beloved Marin Team Issue won't
>>> stay true anymore and the LBS says they are ready to go.

>Well that's basically BS unless they showed you cracks or
>kinks from crashing.

>> What the heck does he mean "They won't stay true
>> anymore". I have only had a single pair of rims that
>> wouldn't stay true, and these were heat-treated rims.
>> Once they bent, they NEVER got true again, because they
>> were just too darned stiff.

>No matter how much you heat treat aluminum or work harden
>it, it's elasticity does not change. I suspect the
>wheelbuilder who made the assessment you express had no
>idea of how to true a wobbly wheel, or for that matter,
>what to do if a rim gets a non-fatal wow in it. This has
>nothing to do with heat treatment.

Jobst, sometimes you are just so full of so much arrogant
B.S. I have bent early heat-treated rim, circa 1985, from a
TREK 500, look up the rim if you are ignorant of the history
of these cycle parts, they are on www.vintage-trek.com.
Today's rims do not have the same stiffness properties. My
local bike shop, the most experienced one in town, said they
could not bring the rim fully back into true, which I did
not believe because I had never seen such a problem before,
so i verified the problem myself on a truing stand before I
discarded the rim.

I was stupid enough to buy a second rim of the same type and
have them install it, and after another big pothole it
happened again, the rim would come back into round but would
not true-up side-side, and at that point, I bought a whole
new set of unanodized cheapo wheels from Nashbar for $60,
and never had another problem with them.

Are you denying both incidencts, Jobst, Baby ??

Jobst, sometimes you are just so full of so much
arrogance and B.S.

- Don Gillies San Diego, CA
 
[email protected] writes:

>Donald Gillies writes:

>>> The Mavic 517's on my beloved Marin Team Issue won't
>>> stay true anymore and the LBS says they are ready to go.

>Well that's basically BS unless they showed you cracks or
>kinks from crashing.

>> What the heck does he mean "They won't stay true
>> anymore". I have only had a single pair of rims that
>> wouldn't stay true, and these were heat-treated rims.
>> Once they bent, they NEVER got true again, because they
>> were just too darned stiff.

>No matter how much you heat treat aluminum or work harden
>it, it's elasticity does not change. I suspect the
>wheelbuilder who made the assessment you express had no
>idea of how to true a wobbly wheel, or for that matter,
>what to do if a rim gets a non-fatal wow in it. This has
>nothing to do with heat treatment.

irrelevant.

My rims experienced plastic deformation. the yield strength
can be increased by heat treating. therefore, if the rims
had not been heat treated, plastic deformation might have
been less, or alternately, the higher yield strength meant
that my spokes could no longer pull the rim straight by
exceeding the now-increased yield-strength, now that the
rims had been bent.

check your facts, jobst.

- Don Gillies San Diego, CA
 
Donald Gillies writes:

>>>> The Mavic 517's on my beloved Marin Team Issue
>>>> won't stay true anymore and the LBS says they are
>>>> ready to go.

>> Well that's basically BS unless they showed you cracks or
>> kinks from crashing.

>>> What the heck does he mean "They won't stay true
>>> anymore". I have only had a single pair of rims that
>>> wouldn't stay true, and these were heat-treated rims.
>>> Once they bent, they NEVER got true again, because they
>>> were just too darned stiff.

>> No matter how much you heat treat aluminum or work harden
>> it, it's elasticity does not change. I suspect the
>> wheelbuilder who made the assessment you express had no
>> idea of how to true a wobbly wheel, or for that matter,
>> what to do if a rim gets a non-fatal wow in it. This has
>> nothing to do with heat treatment.

> irrelevant.

> My rims experienced plastic deformation. the yield
> strength can be increased by heat treating. therefore, if
> the rims had not been heat treated, plastic deformation
> might have been less, or alternately, the higher yield
> strength meant that my spokes could no longer pull the rim
> straight by exceeding the now-increased yield-strength,
> now that the rims had been bent.

That's a different story but a higher yield strength still
does not effect truing the wheel. Besides, I am not the
least convinced that these rims have a higher yield strength
than others, having straightened many wheels with rims of
different designs. If the wheel is bent it cannot readily be
plastically deformed back into alignment with spoke
adjustments. That must be done by first carefully bending
the rim manually until the it is near planar before
beginning with spoke adjustments.

Recently at a coastal hangout, the San Gregorio store, where
an assortment of motorcyclists often stop, one of them
knocked down my friends bicycle and roared away, riding over
the rear wheel and leaving it a pretzel. That was a classic
bend and re-bend exercise after which the re-trued wheel has
survived a few hundred miles. Without careful inspection it
does not reveal its trauma.

> check your facts, jobst.

Those are my facts. I think either your wheel was worse off
than described or you need a better wheel builder. In any
case, when I hear that heat treatment is the culprit, I
doubt the assessment.

Jobst Brandt [email protected]
 
Originally posted by Donald Gillies
[email protected] writes:

>Donald Gillies writes:

>>> The Mavic 517's on my beloved Marin Team Issue won't
>>> stay true anymore and the LBS says they are ready to go.

>Well that's basically BS unless they showed you cracks or
>kinks from crashing.

>> What the heck does he mean "They won't stay true
>> anymore". I have only had a single pair of rims that
>> wouldn't stay true, and these were heat-treated rims.
>> Once they bent, they NEVER got true again, because they
>> were just too darned stiff.

>No matter how much you heat treat aluminum or work harden
>it, it's elasticity does not change. I suspect the
>wheelbuilder who made the assessment you express had no
>idea of how to true a wobbly wheel, or for that matter,
>what to do if a rim gets a non-fatal wow in it. This has
>nothing to do with heat treatment.

Jobst, sometimes you are just so full of so much arrogant
B.S. I have bent early heat-treated rim, circa 1985, from a
TREK 500, look up the rim if you are ignorant of the history
of these cycle parts, they are on www.vintage-trek.com.
Today's rims do not have the same stiffness properties. My
local bike shop, the most experienced one in town, said they
could not bring the rim fully back into true, which I did
not believe because I had never seen such a problem before,
so i verified the problem myself on a truing stand before I
discarded the rim.

I was stupid enough to buy a second rim of the same type and
have them install it, and after another big pothole it
happened again, the rim would come back into round but would
not true-up side-side, and at that point, I bought a whole
new set of unanodized cheapo wheels from Nashbar for $60,
and never had another problem with them.

Are you denying both incidencts, Jobst, Baby ??

Jobst, sometimes you are just so full of so much
arrogance and B.S.

- Don Gillies San Diego, CA

Dear Don and Jobst,

Don, I've looked at the site that you mention:

www.vintage-trek.com

I couldn't find any search function. The pdf file for
the 1985 (sport section) mentions nothing about
the Trek 500 model's rims, nor could I find any mention
of odd rims on the site. Can you provide a link to the
actual page about these rims that you have in mind?

If I follow you, you're saying that your 1985 Trek 500
had unusual heat-treated aluminum rims that, when
bent, work-hardened so much that they resisted being
pulled back into shape by spoke tension? But until
bent by an accident, they could be trued by normal
means?

Jobst, you're handling the abuse admirably. It can't
be easy.

Carl Fogel
 
[email protected] wrote:
> ... If the wheel is bent it cannot readily be plastically
> deformed back into alignment with spoke adjustments. That
> must be done by first carefully bending the rim manually
> until the it is near planar before beginning with spoke
> adjustments.

> Recently at a coastal hangout, the San Gregorio store,
> where an assortment of motorcyclists often stop, one of
> them knocked down my friends bicycle and roared away,
> riding over the rear wheel and leaving it a pretzel. That
> was a classic bend and re-bend exercise after which the
> re-trued wheel has survived a few hundred miles. Without
> careful inspection it does not reveal its trauma.

Ouch. Sportbike, or Harley? My experience is that the
sportbike riders are on average more annoying to share the
road with. So what is the recommended procedure for fixing a
taco - loosen spokes somewhat, attempt to bend the rim back
closer to true, make adjustments with spoke tension? I had
to do this a couple of days ago. Jobst, you would know the
spot - it was descending Highland Way in Santa Cruz County,
shortly after climbing Eureka Canyon:

http://www.topozone.com/map.asp?z=10&n=4103555&e=603442&s=1-
00&size=l&datum=nad83&layer=DRG25

The road is quite rough and I hit a pothole hard a few miles
from nowhere. It was a little odd as the wheel was severely
tacoed yet I didn't even pinch-flat. Fortunately, a local
gave me a ride to the Summit store where I could have used
the phone, though in fact I was able to straighten the wheel
enough to ride home before dark.

So, once safely home and reinforced with hot tea or cold
beer as applicable, what is the best long term fix?
Detension all spokes and straighten the rim by bending?
 
[email protected] wrote:
> Donald Gillies writes:
>
>
>>>The Mavic 517's on my beloved Marin Team Issue won't stay
>>>true anymore and the LBS says they are ready to go.
>
>
> Well that's basically BS unless they showed you cracks or
> kinks from crashing.
>
>
>>What the heck does he mean "They won't stay true anymore".
>>I have only had a single pair of rims that wouldn't stay
>>true, and these were heat-treated rims. Once they bent,
>>they NEVER got true again, because they were just too
>>darned stiff.
>
>
> No matter how much you heat treat aluminum or work harden
> it, it's elasticity does not change.

eh? jobst, you really need to go back & revise materials
101. spokes deform without work hardening? work hardening
rims don't lose ductility? honestly, you've been abandoning
all basic materials fundamentals recently.

> I suspect the wheelbuilder who made the assessment you
> express had no idea of how to true a wobbly wheel, or for
> that matter, what to do if a rim gets a non-fatal wow in
> it. This has nothing to do with heat treatment.

heat treatment would /definitely/ affect yield and
ductility, and therefore your ability to repair.

>
>
>>Assuming your rims are normal raw aluminum or anodized
>>aluminum, it should always be possible to pull them true.
>>If not, you can always cut off all the spokes and jump on
>>the rim till it's flat (don't laugh, i've done this
>>before.)
>
>
> Ooooh! That hurts. I see you don't understand wheel
> truing. THAT is not the way it is done to any reasonable
> effect and it's a huge waste of good spokes. Where do you
> get these notions. It sounds so macho however.
>
>
>>I'm thinking that maybe you need either
>
>
>> 1. new spoke prep, plus re-true
>> 2. new set of nipples + spoke prep, plus re-true.
>
>
>>Since option #2 is probably about $3 more expensive than
>>option #1, i'd go with option #2.
>
>
> Both suggestions should go into the trash bin.
>
> Jobst Brandt [email protected]
 
Donald Gillies wrote:
> [email protected] writes:
>
>
>>Donald Gillies writes:
>
>
>>>>The Mavic 517's on my beloved Marin Team Issue won't
>>>>stay true anymore and the LBS says they are ready to go.
>
>
>>Well that's basically BS unless they showed you cracks or
>>kinks from crashing.
>
>
>>>What the heck does he mean "They won't stay true
>>>anymore". I have only had a single pair of rims that
>>>wouldn't stay true, and these were heat-treated rims.
>>>Once they bent, they NEVER got true again, because they
>>>were just too darned stiff.
>
>
>>No matter how much you heat treat aluminum or work harden
>>it, it's elasticity does not change. I suspect the
>>wheelbuilder who made the assessment you express had no
>>idea of how to true a wobbly wheel, or for that matter,
>>what to do if a rim gets a non-fatal wow in it. This has
>>nothing to do with heat treatment.
>
>
> irrelevant.
>
> My rims experienced plastic deformation.

yes

> the yield strength can be
> increased by heat treating.

yes

> therefore, if the rims had not been heat treated, plastic
> deformation might have been less,

no, the reverse.

> or alternately, the higher yield strength meant that my
> spokes could no longer pull the rim straight by exceeding
> the now-increased yield-strength, now that the rims had
> been bent.

that's correct, but you can't arrive at that conclusion from
the statement above!

>
> check your facts, jobst.
>
> - Don Gillies San Diego, CA
 
jim beam <[email protected]> wrote:
> [email protected] wrote:

> > No matter how much you heat treat aluminum or work
> > harden it, it's elasticity does not change.

> eh? jobst, you really need to go back & revise materials
> 101. spokes deform without work hardening? work hardening
> rims don't lose ductility? honestly, you've been
> abandoning all basic materials fundamentals recently.

He said elasticity (Young's modulus), not strength or
ductility. Elasticity doesn't change significantly with
treatment, hardening, or voodoo.

I think Jobst's point is that the rim moves X mm sideways
for Y tension on the spoke and that this number is dependent
on the stiffness of the rim, which is related to cross-
section and modulus. But it's not so closely related to
ultimate tensile strength or ductility (which are affected
by treatment, alloy etc).
 
Benjamin Weiner wrote:
> jim beam <[email protected]> wrote:
>
>>[email protected] wrote:
>
>
>>>No matter how much you heat treat aluminum or work harden
>>>it, it's elasticity does not change.
>
>
>>eh? jobst, you really need to go back & revise materials
>>101. spokes deform without work hardening? work hardening
>>rims don't lose ductility? honestly, you've been
>>abandoning all basic materials fundamentals recently.
>
>
> He said elasticity (Young's modulus), not strength or
> ductility. Elasticity doesn't change significantly with
> treatment, hardening, or voodoo.

oops! misread it... you're absloutely correct. sorry to
jobst on that one too.

>
> I think Jobst's point is that the rim moves X mm sideways
> for Y tension on the spoke and that this number is
> dependent on the stiffness of the rim, which is related to
> cross-section and modulus. But it's not so closely related
> to ultimate tensile strength or ductility (which are
> affected by treatment, alloy etc).
>

right, but to straighten a rim, it does need to yield, and
that can be affected by any work hardening a rim may have
experienced in deformation.
 
> [email protected] writes:
>>No matter how much you heat treat aluminum or work harden
>>it, it's elasticity does not change.

Donald Gillies wrote:
> Today's rims do not have the same stiffness properties.

Elasticity <> stiffness. Jobst is right, most aluminum
alloys and hardening and heat treating does not change the
elasticity. Stiffness is a function of elasticity *and*
shape. Modern rims may have a different shape than your 1985
Trek, and the stiffness might be different. But I'm not
conviced you could tell other than perhaps your brakes might
rub with a more flexible rim.

> I have bent early heat-treated rim, circa 1985.... My
> local bike shop, the most experienced one in town, said
> they could not bring the rim fully back into true, which I
> did not believe because I had never seen such a problem
> before, so i verified the problem myself on a truing stand
> before I discarded the rim.
>
> I was stupid enough to buy a second rim of the same type
> and have them install it, and after another big pothole it
> happened again, the rim would come back into round but
> would not true-up side-side...

Neither of these experiences has anything to do with
elasticity or stiffness. It appears that your rims went
beyond the yield point, and when you get beyond yield in a
material, it doesn't fully recover its original shape. That
is true whether your material is aluminum, steel, plastic,
ceramic, whatever.

--
Dave dvt at psu dot edu
 
dvt wrote:

> ... Neither of these experiences has anything to do with
> elasticity or stiffness. It appears that your rims went
> beyond the yield point, and when you get beyond yield in a
> material, it doesn't fully recover its original shape.
> That is true whether your material is aluminum, steel,
> plastic, ceramic, whatever.

All plastic material has yielded. ;)

--
Tom Sherman - Quad Cities (Illinois Side)
 

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