Mavic open sport clincher rims

[[email protected]]

someone writes anonymously:

>>> Anyone have experience with or knowledge of these? Could they be
>>> the second coming of the MA2, or something close (he says
>>> optimistically)?

>> It looks like the MA3 with a new name. The MA3 is a cheap, bad rim,
>> which is prone to cracking around the eyelets with common spoke
>> tensions. Even Mavic admits this by specifying a lower rider weight
>> limit for the MA3 than for example Open Pro. The Open Pro is a much
>> better choice.

> What does rider weight have to do with eyelets cracking? Eyelets
> failure is a function of spoke tension not rider weight. Are you
> suggesting the Mavic spec lower spoke tension for the MA3?

The cracks are fatigue failures that develop from load cycles. Spoke
load is at its maximum in the unloaded wheel and drops closer to zero
the greater the wheel load becomes. Therefore, load is a major effect
in fatigue life.

Rim sockets distribute spoke loads to a 0.5" diameter on the inner
wall of the rim and a 3/8" diameter on the outer wall. For this
reason socketed rims seldom suffer cracks and high spoke tension is
not a fatigue failure consideration. In the days when all good rims
had sockets and eyelets, tension was limited primarily by compression
buckling (spontaneous pretzel) of the rim that defined the tension
limit. I have not seen any rims made today that work at that level
and that is why we need thread glue to keep spoke nipples from
unscrewing because they cannot be made tight enough to not become
slack without cracking rims.

Jobst Brandt

 

[Michael Press]

In article <[email protected]>,
[email protected] wrote:

> someone writes anonymously:
>
> >>> Anyone have experience with or knowledge of these? Could they be
> >>> the second coming of the MA2, or something close (he says
> >>> optimistically)?
>
> >> It looks like the MA3 with a new name. The MA3 is a cheap, bad rim,
> >> which is prone to cracking around the eyelets with common spoke
> >> tensions. Even Mavic admits this by specifying a lower rider weight
> >> limit for the MA3 than for example Open Pro. The Open Pro is a much
> >> better choice.
>
> > What does rider weight have to do with eyelets cracking? Eyelets
> > failure is a function of spoke tension not rider weight. Are you
> > suggesting the Mavic spec lower spoke tension for the MA3?
>
> The cracks are fatigue failures that develop from load cycles. Spoke
> load is at its maximum in the unloaded wheel and drops closer to zero
> the greater the wheel load becomes. Therefore, load is a major effect
> in fatigue life.
>
> Rim sockets distribute spoke loads to a 0.5" diameter on the inner
> wall of the rim and a 3/8" diameter on the outer wall. For this
> reason socketed rims seldom suffer cracks and high spoke tension is
> not a fatigue failure consideration. In the days when all good rims
> had sockets and eyelets, tension was limited primarily by compression
> buckling (spontaneous pretzel) of the rim that defined the tension
> limit. I have not seen any rims made today that work at that level
> and that is why we need thread glue to keep spoke nipples from
> unscrewing because they cannot be made tight enough to not become
> slack without cracking rims.

Sun CR-18. I tensioned one until it became a circle on a
surface of negative curvature. I reduced the tension to
bring it flat, and raised the tension to the maximum, then
trued, balanced, and stress-relieved. Two years later it
and its brother are true with no cracking. $20 US.
Eyelets, but no sockets.

--
Michael Press

 

[Chalo]

Michael Press wrote:
>
> Sun CR-18. I tensioned one until it became a circle on a
> surface of negative curvature. I reduced the tension to
> bring it flat, and raised the tension to the maximum, then
> trued, balanced, and stress-relieved. Two years later it
> and its brother are true with no cracking. $20 US.
> Eyelets, but no sockets.

Sun rims are made of _much_ more ductile material than Mavic rims.
Based on my experience with them, I would expect them to pucker at the
eyelets at a lower spoke tension than what would cause them to crack
there.

I find Sun rims to be much more reliable than recent Mavic rims. That
said, the CR18 is a significantly heavier rim than the MA3, Open Pro,
etc., and should be expected to display superior reliability on that
basis.

Chalo Colina

 

[Chalo]

I retract my previous comment, upon finding that the claimed weight of
the Sun CR18 is actually 20g less than that of the Mavic Open Sport.
This discovery compounds my disappointment with Mavic's recent
products. Hopefully the market will wise up soon enough; hype can only
carry you so far if there is no substance to back it up.

Chalo

 

[Antti Salonen]

[email protected] wrote:

> What does rider weight have to do with eyelets cracking? Eyelets failure is
> a function of spoke tension not rider weight.

Yes, but heavier riders need higher spoke tensions for the wheel to be
reliable, if everything else is equal.

> Are you suggesting the Mavic spec lower spoke tension for the MA3?

It was reported here that the specified rider weight limit is lower for
MA3, unless my memory fails. Perhaps by Peter Chisholm?

-as

 

[Peter Cole]

Zog The Undeniable wrote:
> Peter Cole wrote:
>
>> Since it's not a significant proportion of the ~0.5mm service wear
>> depth, it won't be a significant factor for the lifetime of the rim.
>> Kind of like a car feature that stops working after 5K miles -- IOW, a
>> scam.
>
>
> The original idea of machined sidewalls was to clean off the anodising,
> which plays havoc with wet braking. In the old days WTB actually sold
> abrasive pads to grind that expensive anodising off the brake tracks,
> after which you could switch to normal pads.
>
> So machined rims offer better braking than completely anodised rims, but
> not better than a plain alu rim. The rim manufacturers created a
> problem then invented something else to fix it. The consumer gets the
> bill for both.

I think you're right about that. I bought a pair of dark anodized Open
Pros (w/o machined brake track) that grabbed/chattered terribly until
the anodizing wore off (something that took a long time).

 

[Chalo]

jim beam wrote:
>
> Chalo wrote:
> >
> > Open Sports are heavier.
>
> than ma2's?

Claimed weight 490g.

> > So are most deep rims if I'm not mistaken.
>
> open pros are 420g. that's a good deal less shallow than a 460g ma2.

Still not a deep rim. I'd be surprised if it were more durable or more
resistant to any kind of damage than its predecessor.

> the flat wall of a new machines rim mates completely with the flat
> profile of a new pad. 100% braking, day 1. a curved rim, ma2, + new
> flat brake pad makes <50% contact day 1. your call on which is safer.

I think you've illustrated which one has more contact area on day 1.
In any case, frictional force is not proportional to surface contact
area, but to load and frictional coefficient. Kool Stop Continentals
(with a small area) work the same as Kool Stop Mountain pads (with a
large area) on the same brake. And just as you imply, after a few
miles they're all 100% conformal.

> >>8. welded joints offer better mechanical strength
> >
> > Not for Mavics, they don't.
>
> sorry, but welded joints are nearly as strong at the parent material.
> that's /not/ the case with a pinned joint.
>
> > Try to tension new welded Mavics up enough
> > to carry a good load, and they will bulge at the weld before they start
> > to squish at the valve hole.
>
> dude, if you're tensioning a rim that high, you're insane and have *NO*
> right to complain about equipment failure.

I haven't squished a valve hole in a long time. Most of the time, I
did so when I was tying to true up a tired rim without making any of
the spokes too loose.

When I squished a welded joint on a Mavic rim recently, it was at a
tension that wasn't high enough to keep the left side rear spokes from
loosening-- a lower tension than what I have on some of my other 700c
rims of equal or ligher weight without problems.

The fact that the rim pooched out at the welded joint, rather than at
the valve hole where the cross section is considerably less, is
conclusive proof that you are wrong about the welded joint being
"nearly as strong as the parent material". The _annealed_ version of
the parent material, maybe, but that's a completely different thing.

> But it's clear to me that the MA2 was not
> > seriously flawed in in any particular way,
>
> for those of us that have lived outside of palo alto, you know, where it
> might rain occasionally, sockets that rust are a big problem. rims that
> flat spot are a problem.

The MA2s I built for my sweetie see use in all kinds of weather here in
Seattle. No rust yet, but maybe one day; you never know.

> open pros are a great rim. light, strong, doesn't
> crack, doesn't rust, lasts. available in silver anodized, black
> anodized, cd anodized & ceramic. no reliability problems as far as i know.

I'll have to take your word for it. Their reputation among cycle
messengers here is not stellar, but a lot of them use tham anyway. The
T519 and A719 rims I have tried recently have been utter junk-- heavy
touring/commuting rims that couldn't withstand heavy touring/commuting
conditions.

Chalo

 

Yes I agree. Heavier riders need more spoke tension, or more spokes than
lighter riders, all else being equal. So as Jobst stated the rim may be too
weak for the spoke tension required to maintain a true wheel without
fatiguing. If you laced with a lower tension the eyelets would not crack;
however the rims would not stay true. If this is the case with the ma3, then
they are not suitable for all but the lightest riders and there are better
choices.

cel


"Antti Salonen" <[email protected]> wrote in message
news:[email protected]...
> [email protected] wrote:
>
> > What does rider weight have to do with eyelets cracking? Eyelets failure
is
> > a function of spoke tension not rider weight.
>
> Yes, but heavier riders need higher spoke tensions for the wheel to be
> reliable, if everything else is equal.
>
> > Are you suggesting the Mavic spec lower spoke tension for the MA3?
>
> It was reported here that the specified rider weight limit is lower for
> MA3, unless my memory fails. Perhaps by Peter Chisholm?
>
> -as

 

[dvt]

Chalo wrote:
> Mark Hickey wrote:
>>"Chalo" <[email protected]> wrote:

>>>Besides, aren't you the guy who says spoke gauge has an effect on ride
>>>quality? If you can feel that, then I don't know why you wouldn't
>>>prefer shallow rims since they have a much more pronounced effect on
>>>radial deflection. (Not that I can feel any.)

>>It seems to me that if Chalo
>>can't feel vertical deflection on his rims / spokes / frame - the rest
>>of us don't stand a chance of doing so. He's going to get (at least)
>>2.5x as much deflection out of his equipment as I can (and a LOT more
>>than all but the very biggest of us).

> You know, it could just be that I'm grossly insensitive.

Chalo rides much larger tyres than the rest of us, too. If the rest of
the bike is as stiff as my bike, but Chalo has larger and softer tyres,
I think he'd be *less* prone to sense any changes in the bike.

--
Dave
dvt at psu dot edu

 

[Chalo]

dvt wrote:
>
>
> Chalo rides much larger tyres than the rest of us, too. If the rest of
> the bike is as stiff as my bike, but Chalo has larger and softer tyres,
> I think he'd be *less* prone to sense any changes in the bike.

That's an interesting notion, and I'm sure it it may be relevant for
tires like my favorite 700x60 Schwalbe Big Apples, which I run at a
modest 50psi or so. However, it's a fact that a fatter tire is
"harder" (that is, it displays less vertical travel on a given bump)
than a skinny tire at the same pressure. So my 700x32 tires at 105psi
give a harder ride than 700x23 tires at the same pressure.

In the basis of footprint size, my Big Apples should be yielding a
harder ride than skinny road bike tires too, but they don't seem to do
that in practice. I suspect that it has to do with the rim's
deflection into the tire casing rather than the tire's deflection at
its contact patch.

Chalo Colina

 

[[email protected]]

The next rim up the line, the Mavic Open Pro, might be OK. The Open Pro
is a lightweight rim with sockets.

 

[Qui si parla Campagnolo]

[email protected] wrote:
> someone writes anonymously:
>
> >>> Anyone have experience with or knowledge of these? Could they be
> >>> the second coming of the MA2, or something close (he says
> >>> optimistically)?
>
> >> It looks like the MA3 with a new name. The MA3 is a cheap, bad rim,
> >> which is prone to cracking around the eyelets with common spoke
> >> tensions. Even Mavic admits this by specifying a lower rider weight
> >> limit for the MA3 than for example Open Pro. The Open Pro is a much
> >> better choice.
>
> > What does rider weight have to do with eyelets cracking? Eyelets
> > failure is a function of spoke tension not rider weight. Are you
> > suggesting the Mavic spec lower spoke tension for the MA3?
>
> The cracks are fatigue failures that develop from load cycles. Spoke
> load is at its maximum in the unloaded wheel and drops closer to zero
> the greater the wheel load becomes. Therefore, load is a major effect
> in fatigue life.
>
> Rim sockets distribute spoke loads to a 0.5" diameter on the inner
> wall of the rim and a 3/8" diameter on the outer wall. For this
> reason socketed rims seldom suffer cracks and high spoke tension is
> not a fatigue failure consideration. In the days when all good rims
> had sockets and eyelets, tension was limited primarily by compression
> buckling (spontaneous pretzel) of the rim that defined the tension
> limit. I have not seen any rims made today that work at that level
> and that is why we need thread glue to keep spoke nipples from
> unscrewing because they cannot be made tight enough to not become
> slack without cracking rims.

???_ I think ya need to build a few wheels Jobst. Use a CXP-33, An
OpenPro, A Velocity Fusion, Aerohead, Deep V(no eyelets!!!). The wheels
we build don't have nipples loosen, don't crack and none have thread
'glue'.

yes, yes, yes, the MA-2 was a wonderful rim but it's gone now......


>
> Jobst Brandt

 

[Qui si parla Campagnolo]

Antti Salonen wrote:
> [email protected] wrote:
>
> > What does rider weight have to do with eyelets cracking? Eyelets failure is
> > a function of spoke tension not rider weight.
>
> Yes, but heavier riders need higher spoke tensions for the wheel to be
> reliable, if everything else is equal.
>
> > Are you suggesting the Mavic spec lower spoke tension for the MA3?
>
> It was reported here that the specified rider weight limit is lower for
> MA3, unless my memory fails. Perhaps by Peter Chisholm?

Early in it's life, we saw so many MA-3s crack and fail, with little
riders, big riders, no riders, that we stopped selling them and sent
the dozen or so we had back to mavic. We then used the Velocity Aero as
our low end rim and had great results with those. Not 'sexy', but a
good rim for not a lot of $-the Velocity Aero.
>
> -as

 

[Sandy]

Dans le message de news:[email protected],
Qui si parla Campagnolo <[email protected]> a réfléchi, et puis a déclaré :
> Antti Salonen wrote:
>> [email protected] wrote:
>>
>>> What does rider weight have to do with eyelets cracking? Eyelets
>>> failure is a function of spoke tension not rider weight.
>>
>> Yes, but heavier riders need higher spoke tensions for the wheel to
>> be reliable, if everything else is equal.
>>
>>> Are you suggesting the Mavic spec lower spoke tension for the MA3?
>>
>> It was reported here that the specified rider weight limit is lower
>> for MA3, unless my memory fails. Perhaps by Peter Chisholm?
>
> Early in it's life, we saw so many MA-3s crack and fail, with little
> riders, big riders, no riders, that we stopped selling them and sent
> the dozen or so we had back to mavic. We then used the Velocity Aero
> as our low end rim and had great results with those. Not 'sexy', but a
> good rim for not a lot of $-the Velocity Aero.
>>
You often mention this rim, but I didn't know you consider it low end. What
are the other rims, in some sort of ascending order that you like to build
with ?
--
Sandy

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

 

[Nate Knutson]

[email protected] wrote:

> In the days when all good rims
> had sockets and eyelets, tension was limited primarily by compression
> buckling (spontaneous pretzel) of the rim that defined the tension
> limit. I have not seen any rims made today that work at that level
> and that is why we need thread glue to keep spoke nipples from
> unscrewing because they cannot be made tight enough to not become
> slack without cracking rims.
>
> Jobst Brandt

Jobst,
I think there are some rims today that more or less work at this level
of tension, the one you describe and advocate in your book. (Of course
it's beyond mediocre that all we have is "some" rims that "more or
less" work, and that even this is debatable).

But if you feel this way about all current rims, shouldn't you update
"The Bicycle Wheel" accordingly? It does warn against anodization,
single eyelets, etc, but it doesn't say "don't use this method of
determing proper tension on anodized or single-eyeleted rims." Since a
lot of people get pointed to your book, and they're not exactly all
buying MA-2's off ebay, wouldn't something like this be appropriate?

Regards,
Nate Knutson

 

[Nate Knutson]

Qui si parla Campagnolo wrote:

> Early in it's life, we saw so many MA-3s crack and fail, with little
> riders, big riders, no riders, that we stopped selling them and sent
> the dozen or so we had back to mavic. We then used the Velocity Aero as
> our low end rim and had great results with those. Not 'sexy', but a
> good rim for not a lot of $-the Velocity Aero.

Hm... does this mean there was a time when they were less than just a
bit under the cost of the other Velocity rims? Because if the current
price is your definition of low end then... well, lucky you.

 

[[email protected]]

Nate Knutson writes:

>> In the days when all good rims had sockets and eyelets, tension was
>> limited primarily by compression buckling (spontaneous pretzel) of
>> the rim that defined the tension limit. I have not seen any rims
>> made today that work at that level and that is why we need thread
>> glue to keep spoke nipples from unscrewing because they cannot be
>> made tight enough to not become slack without cracking rims.

> I think there are some rims today that more or less work at this
> level of tension, the one you describe and advocate in your
> book. (Of course it's beyond mediocre that all we have is "some"
> rims that "more or less" work, and that even this is debatable).

> But if you feel this way about all current rims, shouldn't you
> update "The Bicycle Wheel" accordingly? It does warn against
> anodization, single eyelets, etc, but it doesn't say "don't use this
> method of determining proper tension on anodized or single-eyeleted
> rims." Since a lot of people get pointed to your book, and they're
> not exactly all buying MA-2's off eBay, wouldn't something like this
> be appropriate?

There is a problem with that because the book is a product of its
time, when practically everything in it was new and counter to myth
and lore of that time. I think it best to leave it as a classic,
because a patch here and there is like letting the camel's nose into
the tent. Although there are still folks in the bicycle business who
keep old beliefs alive, most have moved on. Defining effective rim
diameter was a novelty while today ERD is used by most everyone as
common jargon. Should those things also be deleted?

The main change in the book was replacing tubular tire rims with
clincher rims. The rest is ageless and will not change. Spinergy
four blade spokes are not part of this, nor are TriSpoke. These are
passing fads and to try to keep up with them is fruitless. The
36-spoke wheel is still as valid as always, except that the number of
riders who expect durable wheels has greatly diminished. As you see
here, people have racing and training wheels (most of whom NEVER race)
but what is the difference in these wheels?

On out local Foothill Expressway, that is straight and with less than
3% maximum grade, you can see the latest equipment roll by in droves.
In fact it's hard to find a fad bicycle with wheels more than a year
old, the fashion participants always having the latest.

Jobst Brandt

 

[jim beam]

[email protected] wrote:
> Nate Knutson writes:
>
>
>>>In the days when all good rims had sockets and eyelets, tension was
>>>limited primarily by compression buckling (spontaneous pretzel) of
>>>the rim that defined the tension limit. I have not seen any rims
>>>made today that work at that level and that is why we need thread
>>>glue to keep spoke nipples from unscrewing because they cannot be
>>>made tight enough to not become slack without cracking rims.
>
>
>>I think there are some rims today that more or less work at this
>>level of tension, the one you describe and advocate in your
>>book. (Of course it's beyond mediocre that all we have is "some"
>>rims that "more or less" work, and that even this is debatable).
>
>
>>But if you feel this way about all current rims, shouldn't you
>>update "The Bicycle Wheel" accordingly? It does warn against
>>anodization, single eyelets, etc, but it doesn't say "don't use this
>>method of determining proper tension on anodized or single-eyeleted
>>rims." Since a lot of people get pointed to your book, and they're
>>not exactly all buying MA-2's off eBay, wouldn't something like this
>>be appropriate?
>
>
> There is a problem with that because the book is a product of its
> time, when practically everything in it was new and counter to myth
> and lore of that time. I think it best to leave it as a classic,

eh? so why the previous revisions??? why did you leave in such howlers
as the confusion between strain aging & non-strain aging materials? if
you fixed that and some of your other fundamental mistakes, you might
find more consulting work coming your way, but as things stand, anyone
that knows what they're looking at wouldn't hire you because "the book"
makes you look, er, "underinformed".

> because a patch here and there is like letting the camel's nose into
> the tent. Although there are still folks in the bicycle business who
> keep old beliefs alive, most have moved on. Defining effective rim
> diameter was a novelty while today ERD is used by most everyone as
> common jargon. Should those things also be deleted?

eh? you invented erd??? so how did anyone calculate spoke length
before you came along? sounds just like your story about inventing
"stress relief" [otherwise known as bedding the spokes in], even though
the practice predates your birth.

>
> The main change in the book was replacing tubular tire rims with
> clincher rims. The rest is ageless and will not change. Spinergy
> four blade spokes are not part of this, nor are TriSpoke. These are
> passing fads and to try to keep up with them is fruitless. The
> 36-spoke wheel is still as valid as always, except that the number of
> riders who expect durable wheels has greatly diminished. As you see
> here, people have racing and training wheels (most of whom NEVER race)
> but what is the difference in these wheels?
>
> On out local Foothill Expressway, that is straight and with less than
> 3% maximum grade, you can see the latest equipment roll by in droves.
> In fact it's hard to find a fad bicycle with wheels more than a year
> old, the fashion participants always having the latest.
>
> Jobst Brandt

 

[Qui si parla Campagnolo]

Sandy wrote:
> Dans le message de news:[email protected],
> Qui si parla Campagnolo <[email protected]> a réfléchi, et puis a déclaré :
> > Antti Salonen wrote:
> >> [email protected] wrote:
> >>
> >>> What does rider weight have to do with eyelets cracking? Eyelets
> >>> failure is a function of spoke tension not rider weight.
> >>
> >> Yes, but heavier riders need higher spoke tensions for the wheel to
> >> be reliable, if everything else is equal.
> >>
> >>> Are you suggesting the Mavic spec lower spoke tension for the MA3?
> >>
> >> It was reported here that the specified rider weight limit is lower
> >> for MA3, unless my memory fails. Perhaps by Peter Chisholm?
> >
> > Early in it's life, we saw so many MA-3s crack and fail, with little
> > riders, big riders, no riders, that we stopped selling them and sent
> > the dozen or so we had back to mavic. We then used the Velocity Aero
> > as our low end rim and had great results with those. Not 'sexy', but a
> > good rim for not a lot of $-the Velocity Aero.
> >>
> You often mention this rim, but I didn't know you consider it low end. What
> are the other rims, in some sort of ascending order that you like to build
> with ?
> --
> Sandy

All the rims we sell make for good wheels. Their hierarchy really is
based on price rather than weight but
-least expensive-Velocity Aero and Mavic OpenSport(we'll see)-both in
the $35-$40 range
-For light riders-Velocity Aerohead with the OC rear-$65
-For heavier-Mavic OpenPro and Velocity Fusion-same prices but a wee
bit heavier than Aerohead
-Beefiest rims-Velocity Deep V and Mavic CXP-33-aero-ish but for big
riders
-Mavic T-719 and Velocity Dyad for tourers.

AND-Velocity Escape and Mavic Reflex for tubular rims. Velocity VERY
light..Reflex ala the OpenPro weight.

Of all these rims and we build 'successful' wheels about 400 times or
so each year, only one is 'socketed'(OpenPro). Contrary to what some
say, no eyelet rims work fine, no need to glue nipps to spokes, can
take the tension and be reliable. 'Some' need to update their knowledge
of current rims and not rely on some info in a web site.

 

[Qui si parla Campagnolo]

Nate Knutson wrote:
> Qui si parla Campagnolo wrote:
>
> > Early in it's life, we saw so many MA-3s crack and fail, with little
> > riders, big riders, no riders, that we stopped selling them and sent
> > the dozen or so we had back to mavic. We then used the Velocity Aero as
> > our low end rim and had great results with those. Not 'sexy', but a
> > good rim for not a lot of $-the Velocity Aero.
>
> Hm... does this mean there was a time when they were less than just a
> bit under the cost of the other Velocity rims? Because if the current
> price is your definition of low end then... well, lucky you.

MA-3 was about $30 I think, Velocity Aeros(not AeroHEAD) are about the
same.