Mavic introduces wheel with compression spokes

On Jun 20, 10:07 am, Jobst Brandt wrote:
...What is it a wheel must do in a race that
is different from non-race riding....

The racing wheel must look cool in the Velonews pictures. No cost
effective, reliable, boring 36-spoke wheels need apply.

--
Tom Sherman - Holstein-Friesland Bovinia
The weather is here, wish you were beautiful

On Jun 20, 11:00 am, Ron Ruff wrote:
steve wrote:
Mavic designers and engineers identified spoke stiffness
and flange spacing as the biggest contributors to a wheel's lateral
rigidity, while rim stiffness, spoke length, hub flange diameter, and
spoke lacing patterns all are said to offer little significant
influence.

When I modeled a wheel I got the same result. Flange spacing (or
actually bracing angle) has an exponential effect on lateral stiffness
and the spoke stiffness has almost a linear effect. The rim stiffness
effect was way below linear.

I was surprised to hear that rim
stiffness has such a small influence on lateral stiffness. I notice a
huge difference between a deepV rim and a open pro rim when it comes
to lateral stiffness, assuming the same hub and spokes are used in
both wheels.

Did you measure this? "Seat of the pants" measurements are unreliable
for these things... Mavic also built 2 sets of wheels that were
indentical except that one had 4 times the lateral stiffness of the
other. Riders could not accurately identify which was which.

Very interesting. I am basing my assumtion off of putting the hub on
the ground and appling a lateral load to both sides of the wheel.
Well you learn something new every day. I guess I don't have the
mathematical knowledge to be able to model a rim of different
stiffnesses to see how it would effect overall wheel stiffness.
On a different note you have to imagine that these new wheels will
have pretty poor aerodynamics with 4mm diameter round spokes.

Steve Sauter

On Jun 20, 11:07 am, wrote:
Steve Sauter writes:

http://thisjustin.bicycling.com/2007...vic_wheel.html

The description seems to me to be hopelessly confused, but there
is a photograph showing how the carbon-fiber spokes connect to the
hub.
well /this/

http://tinyurl.com/2m59r9

sure isn't a compression fitting!
According towww.cyclingnews.comthe carbon spokes are in tension
but are designed to handle compressive loads as well. This allows
them to make a wheel with lower spoke tension thus a lighter rim
since it doesn't have to handle as much stress from the spokes.
Mavic has also finally given in to the asymmetric rim design for
there new wheels in order to help balance spoke tension. The reason
for the aluminum spokes on the drive side in the rear wheel is so
that they could use thin bladed spokes and thus place them as far
away from the center of the hub as possible. It looks like the
front wheel uses 18 spokes and the rear uses 24.
It sounds like a decent racing wheel to me but I am a bit skeptical
about how it will hold up for the general public.

I don't understand what the difference between racing and other
bicycling has for wheels. What is it a wheel must do in a race that
is different from non-race riding. I seem to see differences implied
that one is a greater stress than the other but the more stressful one
changes depending on what point is being put forth.

From what I see cruising up and down the avenue here, the all look
like racing wheels, some costing as much as $4000 a pair, according to
our local bicycle shops.

Jobst Brandt

I guess I have always viewed a racing wheel as one that must have
great performance, i.e light weight, aerodynamic, or stiff, but not
necessarily durable or able to take varying amounts of stress for long
periods of time. Especially in the upper levels of racing were most
racers are sponsored and performance is all that matters. On the
other hand a wheel that is good for the general public would be one
that has a lot of the characteristics that a race wheel has but is
also durable and able to last a long time without needing to be
maintained. I consider the general public to be people that love to
ride and even compete but do not have disposable incomes or are
sponsored.

Steve Sauter

Steve Sauter writes:

http://thisjustin.bicycling.com/2007...vic_wheel.html

The description seems to me to be hopelessly confused, but there
is a photograph showing how the carbon-fiber spokes connect to the
hub.

well /this/

http://tinyurl.com/2m59r9

sure isn't a compression fitting!

According towww.cyclingnews.comthe carbon spokes are in tension
but are designed to handle compressive loads as well. This allows
them to make a wheel with lower spoke tension thus a lighter rim
since it doesn't have to handle as much stress from the spokes.
Mavic has also finally given in to the asymmetric rim design for
there new wheels in order to help balance spoke tension. The reason
for the aluminum spokes on the drive side in the rear wheel is so
that they could use thin bladed spokes and thus place them as far
away from the center of the hub as possible. It looks like the
front wheel uses 18 spokes and the rear uses 24.
It sounds like a decent racing wheel to me but I am a bit skeptical
about how it will hold up for the general public.

I don't understand what the difference between racing and other
bicycling has for wheels. What is it a wheel must do in a race that
is different from non-race riding. I seem to see differences implied
that one is a greater stress than the other but the more stressful one
changes depending on what point is being put forth.

From what I see cruising up and down the avenue here, the all look
like racing wheels, some costing as much as $4000 a pair, according to
our local bicycle shops.

I guess I have always viewed a racing wheel as one that must have
great performance, i.e. light weight, aerodynamic, or stiff, but not
necessarily durable or able to take varying amounts of stress for long
periods of time. Especially in the upper levels of racing were most
racers are sponsored and performance is all that matters. On the
other hand a wheel that is good for the general public would be one
that has a lot of the characteristics that a race wheel has but is
also durable and able to last a long time without needing to be
maintained. I consider the general public to be people that love to
ride and even compete but do not have disposable incomes or are
sponsored.

I don't believe anyone can design close enough to the failure stress
to make a reliable wheel that will last only an average 500km. Either
the wheel can withstand a mountain stage of a major race or not, and
that can include heavy braking and rough pavement, no different from
what a athletic tourist would encounter. The fragile description
doesn't hold up for what I see as racing... or touring.

Jobst Brandt

wrote:
Steve Sauter writes:

http://thisjustin.bicycling.com/2007...vic_wheel.html

The description seems to me to be hopelessly confused, but there
is a photograph showing how the carbon-fiber spokes connect to the
hub.

well /this/

http://tinyurl.com/2m59r9

sure isn't a compression fitting!

According towww.cyclingnews.comthe carbon spokes are in tension
but are designed to handle compressive loads as well. This allows
them to make a wheel with lower spoke tension thus a lighter rim
since it doesn't have to handle as much stress from the spokes.
Mavic has also finally given in to the asymmetric rim design for
there new wheels in order to help balance spoke tension. The reason
for the aluminum spokes on the drive side in the rear wheel is so
that they could use thin bladed spokes and thus place them as far
away from the center of the hub as possible. It looks like the
front wheel uses 18 spokes and the rear uses 24.
It sounds like a decent racing wheel to me but I am a bit skeptical
about how it will hold up for the general public.

I don't understand what the difference between racing and other
bicycling has for wheels. What is it a wheel must do in a race that
is different from non-race riding. I seem to see differences implied
that one is a greater stress than the other but the more stressful one
changes depending on what point is being put forth.

From what I see cruising up and down the avenue here, the all look
like racing wheels, some costing as much as $4000 a pair, according to
our local bicycle shops.

I guess I have always viewed a racing wheel as one that must have
great performance, i.e. light weight, aerodynamic, or stiff, but not
necessarily durable or able to take varying amounts of stress for long
periods of time. Especially in the upper levels of racing were most
racers are sponsored and performance is all that matters. On the
other hand a wheel that is good for the general public would be one
that has a lot of the characteristics that a race wheel has but is
also durable and able to last a long time without needing to be
maintained. I consider the general public to be people that love to
ride and even compete but do not have disposable incomes or are
sponsored.

I don't believe anyone can design close enough to the failure stress
to make a reliable wheel that will last only an average 500km.

easy - spoke tension "as high as the rim can bear".

Either
the wheel can withstand a mountain stage of a major race or not, and
that can include heavy braking and rough pavement, no different from
what a athletic tourist would encounter. The fragile description
doesn't hold up for what I see as racing... or touring.

Jobst Brandt

Antti Salonen wrote:
Gary Young wrote:

It was more rigid and at 1355 grams they are one of the
lighter wheel sets on the market (hey - the spokes only way five grams
each - versus an aluminum at eight grams - and we know that every gram
counts)."

The really funny thing is that high-end flat steel spokes like Sapim
CX-Ray or DT Swiss Aerolite are also about five grams each, and they are
a lot more aerodynamic and less likely to break than at least Mavic's
aluminium spokes.

indeed! but it's not just weight, it's elasticity.


I really can't understand why Mavic insists on using aluminium in
spokes, or carbon for that matter, and why anybody would be stupid
enough to buy them at that price. In the wheel tests perfomed in a wind
tunnel Mavic Ksyrium SL or Ksyrium ES have shown to be about as slow as
wheels get. Mavic Ksyrium Elite or Mavic Aksium ($150 a pair or so) are
faster unless you only ride uphill.

Antti

and that's the reason i've not bought any fat-spoke wheels. the skinny
spoke ones are great though.

Kinky Cowboy wrote:
On Tue, 19 Jun 2007 20:42:09 -0700, jim beam
wrote:

Gary Young wrote:
Road Mag's blog had this item today:

" The carbon tubes act like a combination old fashion
wooden spokes, which supported the wheel by compression (like a stiff
wooden spoke on an ox cart) and traditional aluminum spokes that support
the wheel via tension
this was posted yesterday evening, but in the course of nearly 24 hours,
none of our "engineers" have picked up on the most, er, "interesting"
feature in the commentary:

"The carbon tubes act like a combination old fashion wooden spokes,
which supported the wheel by compression (like a stiff wooden spoke on
an ox cart) and traditional aluminum spokes that support the wheel via
tension."

this in the context of a rear wheel with drive side aluminum spokes and
non-drive side carbon i.e. supposedly tension one side, compression the
other.

now, if we know [and understand] our wheel theory, one could ask oneself
how it's possible to have tension on one side of a wheel and compression
on the other, right? any takers? come on, since this comes from an
anonymous and therefore non-credible liar, it should be easy to prove
this is a baseless and inflammatory question...

We all knew that it was so blindingly obvious that either a: something
got lost in the translation or b: Mavic were demonstrating their
ignorance all over again that we wouldn't have to point it out even to
you.


you'da thunk, but judging by the other "blindingly obvious" things that
seem to be accepted without question, [tensiometer math, increasing
tension increases strength, etc.], you gotta wonder. especially as
another day passes without question of this thread's title.

steve wrote:
On Jun 20, 8:51 am, jim beam wrote:
Gary Young wrote:
Another blog posting on the wheel:
http://thisjustin.bicycling.com/2007...vic_wheel.html
The description seems to me to be hopelessly confused, but there is a
photograph showing how the carbon-fiber spokes connect to the hub.
well /this/http://rodale.typepad.com/.shared/image.html?/photos/uncategorized/20...
sure isn't a compression fitting!

According to www.cyclingnews.com the carbon spokes are in tension but
are designed to handle compressive loads as well.

that's what the journalists write, but it's clearly not possible from
that picture.

This allows them to
make a wheel with lower spoke tension thus a lighter rim since it
doesn't have to handle as much stress from the spokes. Mavic has also
finally given in to the asymetric rim design for there new wheels in
order to help balance spoke tension.

asymmetry in what? it's only the rim that really matters for asymmetry,
[since you're stuck with the hub being off center anyway] and that rim
looks symmetric to me.

The reason for the aluminum
spokes on the drive side in the rear wheel is so that they could use
thin bladed spokes and thus place them as far away from the center of
the hub as possible.

that might be true. but then again, the carbon spokes should be less
elastic, so that would mitigate their use...

It lookes like the front wheel uses 18 spokes
and the rear uses 24.
It sounds like a decent racing wheel to me but I am a bit sceptical
about how it will hold up for the general public. I did find this
claim by mavic to be interesting, "In seeking that elusive "third
generation", Mavic designers and engineers identified spoke stiffness
and flange spacing as the biggest contributors to a wheel's lateral
rigidity, while rim stiffness, spoke length, hub flange diameter, and
spoke lacing patterns all are said to offer little significant
influence.

well, bracing angle is the largest factor, but the other points contribute.

More surprisingly, Mavic also claims that spoke tension has
a negligible influence,

of course - tension does not affect stiffness. only if you read certain
books that are unclear on the concept could you get that impression.

and increasing the spoke tension actually
reduces overall lateral rigidity (although it does delay the onset of
complete spoke detensioning)."

in that increasing tension brings the rim closer to buckling, that's true.

I was surprised to hear that rim
stiffness has such a small influence on lateral stiffness. I notice a
huge difference between a deepV rim and a open pro rim when it comes
to lateral stiffness, assuming the same hub and spokes are used in
both wheels.


a stiffer rim makes a wheel stiffer for sure, but the effect is indeed
small compared to the effect of spoke bracing angle.

On Jun 20, 8:26 am, steve wrote:
On Jun 20, 8:51 am, jim beam wrote:

Gary Young wrote:
Another blog posting on the wheel:

http://thisjustin.bicycling.com/2007...vic_wheel.html

The description seems to me to be hopelessly confused, but there is a
photograph showing how the carbon-fiber spokes connect to the hub.

well /this/http://rodale.typepad.com/.shared/image.html?/photos/uncategorized/20...
sure isn't a compression fitting!

According towww.cyclingnews.comthe carbon spokes are in tension but
are designed to handle compressive loads as well. This allows them to
make a wheel with lower spoke tension thus a lighter rim since it
doesn't have to handle as much stress from the spokes. Mavic has also
finally given in to the asymetric rim design for there new wheels in
order to help balance spoke tension. The reason for the aluminum
spokes on the drive side in the rear wheel is so that they could use
thin bladed spokes and thus place them as far away from the center of
the hub as possible. It lookes like the front wheel uses 18 spokes
and the rear uses 24.
It sounds like a decent racing wheel to me but I am a bit sceptical
about how it will hold up for the general public. I did find this
claim by mavic to be interesting, "In seeking that elusive "third
generation", Mavic designers and engineers identified spoke stiffness
and flange spacing as the biggest contributors to a wheel's lateral
rigidity, while rim stiffness, spoke length, hub flange diameter, and
spoke lacing patterns all are said to offer little significant
influence. More surprisingly, Mavic also claims that spoke tension has
a negligible influence, and increasing the spoke tension actually
reduces overall lateral rigidity (although it does delay the onset of
complete spoke detensioning)." I was surprised to hear that rim
stiffness has such a small influence on lateral stiffness.

It's true when said in French.



I notice a
huge difference between a deepV rim and a open pro rim when it comes
to lateral stiffness, assuming the same hub and spokes are used in
both wheels.

Steve Sauter

Dans le message de
oups.com,
Qui si parla Campagnolo a réfléchi, et puis a déclaré :
On Jun 20, 8:26 am, steve wrote:
On Jun 20, 8:51 am, jim beam wrote:

Gary Young wrote:
Another blog posting on the wheel:

http://thisjustin.bicycling.com/2007...vic_wheel.html

The description seems to me to be hopelessly confused, but there
is a photograph showing how the carbon-fiber spokes connect to the
hub.

well
/this/http://rodale.typepad.com/.shared/image.html?/photos/uncategorized/20...
sure isn't a compression fitting!

According towww.cyclingnews.comthe carbon spokes are in tension but
are designed to handle compressive loads as well. This allows them
to make a wheel with lower spoke tension thus a lighter rim since it
doesn't have to handle as much stress from the spokes. Mavic has
also finally given in to the asymetric rim design for there new
wheels in order to help balance spoke tension. The reason for the
aluminum spokes on the drive side in the rear wheel is so that they
could use thin bladed spokes and thus place them as far away from
the center of the hub as possible. It lookes like the front wheel
uses 18 spokes and the rear uses 24.
It sounds like a decent racing wheel to me but I am a bit sceptical
about how it will hold up for the general public. I did find this
claim by mavic to be interesting, "In seeking that elusive "third
generation", Mavic designers and engineers identified spoke stiffness
and flange spacing as the biggest contributors to a wheel's lateral
rigidity, while rim stiffness, spoke length, hub flange diameter, and
spoke lacing patterns all are said to offer little significant
influence. More surprisingly, Mavic also claims that spoke tension
has a negligible influence, and increasing the spoke tension actually
reduces overall lateral rigidity (although it does delay the onset of
complete spoke detensioning)." I was surprised to hear that rim
stiffness has such a small influence on lateral stiffness.

It's true when said in French.

Mercy, Peter! You DO love us!! :-)


--
Sandy
--
S'endormir au volant, c'est très dangereux.
S'endormir à vélo, c'est très rare.
S'endormir à pied, c'est très con.
- Geluck, P.