Plain, Anodized or ceramic coated rims???
joe
or are the plain rims the way to go?
LYDDANS
several responses saying that the ceramic coating is not worth the extra money
and to stay away from it. Some said it tended to flake off. I got the Reflex
Blue wheels and have enjoyed them. Good luck. Jeff.
ILitig8
>or are the plain rims the way to go?
the biggest benifit from ceramic is its increased braking
performance.....especially in the wet
which is probably of more concern to us lowly MTBers....
Ride hard, fall HARDER!
Vandy
Greg F
is why Mavic stopped putting it on the sides. I have the Reflex in blue and
I am happy with them. I have a set of velocity rims that I paid half as
much for that I like just as well.
Best of luck
Greg
joe <m...@here.com> wrote in message
news:36fe28bf...@nntp.interaccess.com...
Paul Grammens
>
> Are the benefits of the coatings on Mavic rims significant?
> or are the plain rims the way to go?
One very important point on the hard gray annodizing: it is prone to
cracking. I'm a big guy, and I replaced one MA-40 after another until
Jobst Brandt kindly explained that the hard anodizing has no benefit and
actually causes cracks to form. Since switching to plain aluminum, no
problems.
-Paul
Sean Bragstad
Actually, Mavic has not stopped anodizing the braking surface of their rims.
The blue Reflex rims that you have were machined *after* anodization.
Current Mavic rims (Open Pro, Reflex tubular) are machined (SUP/Soude usine
process!?) prior to anodization- if you look at a current rim the braking
surface is also dark.
HA rims are really for appearance only, and they do have a tendency to fail
at the eyelet (although my personal experience with properly built HA rims
is that they will "expend" themselves naturally before any eyelets
fail/crack; but I am a relatively puny 145 lbs and ride smoothly)
I have never used a ceramic rim, but at the shop we see that they eat
through brake pads quickly, and are quite expensive.
Thanks and good luck, Sean*******
**** Posted from RemarQ - http://www.remarq.com - Discussions Start Here (tm) ****
tom...@my-dejanews.com
non- ceramic rims if you ride in muddy conditions a lot. The ceramic coating
is supposed to extend the life of the sidewall, but you will go through a lot
more brake pads.
I wore through the rim sidewalls on a pair of Bontrager Mustangs in about 8
months last year, 6 of which were very muddy. I went to ceramic Mustangs last
fall and they're holding up really well so far.
-Tom
In article <19990328121811...@ng-cd1.aol.com>,
ili...@aol.com (ILitig8) wrote:
> >Are the benefits of the coatings on Mavic rims significant?
> >or are the plain rims the way to go?
>
> the biggest benifit from ceramic is its increased braking
> performance.....especially in the wet
> which is probably of more concern to us lowly MTBers....
>
> Ride hard, fall HARDER!
> Vandy
>
-----------== Posted via Deja News, The Discussion Network ==----------
http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own
Jobst Brandt
> Anodized rims quickly loose the color on the braking suface. I
> guess that is why Mavic stopped putting it on the sides. I have the
> Reflex in blue and I am happy with them. I have a set of velocity
> rims that I paid half as much for that I like just as well.
Don't worry, they still anodize them for the fashionable look and then
machine the sides to give the user less material on the braking
surface to wear the rim to death faster and at greater expense. How
about just leaving the material alone and selling the rim... That
won't though work with the fashion industry of bicycling. Helium is IN!
Jobst Brandt <jbr...@hpl.hp.com>
Rick Denney
>Are the benefits of the coatings on Mavic rims significant?
>or are the plain rims the way to go?
The plainer the better. The anodizing causes two problems: It provides
a brittle surface that is a breeding ground for fatigue cracks, and it
ruins braking. Both machined sidewalls and ceramic coatings are
expensive work-arounds for the braking issue, and both create other
problems of their own.
The best rims are plain, non-anodized aluminum like the Mavic MA-2's
that I have on my commuter. As I wear out my other rims, those will be
my replacements.
Rick "You don't always get what you pay for" Denney
Timothy J. Lee
|>Are the benefits of the coatings on Mavic rims significant?
|>or are the plain rims the way to go?
|
|performance.....especially in the wet
Wouldn't ceramic, as an insulator, worsen dry braking performance,
since it reduces heat dissipation through the rim?
--
------------------------------------------------------------------------
Timothy J. Lee timlee@
Unsolicited bulk or commercial email is not welcome. netcom.com
No warranty of any kind is provided with this message.
Kama & John
for all.
Joshua_Putnam
>Don't worry, they still anodize them for the fashionable look and then
>machine the sides to give the user less material on the braking
>surface to wear the rim to death faster and at greater expense. How
>about just leaving the material alone and selling the rim... That
>won't though work with the fashion industry of bicycling. Helium is IN!
There are other brands that have moved to powder coating the rim,
then wire brushing the coating off the brake tracks. You get the
fashion colors without the brittleness of anodizing or the need
to machine the sidewalls. The down side is that these rims are
less expensive, and thus less fashionable.
--
Jo...@WolfeNet.com is Joshua Putnam / P.O. Box 13220 / Burton, WA 98013
http://www.wolfenet.com/~josh/
John Carrier
>machine the sides to give the user less material on the braking
>surface to wear the rim to death faster and at greater expense.
Not so sure about that. The rims start out heavier and then they're
machined down to spec (the new Open Pros are slightly heavier than the old
Open 4CD's). It does provide a more uniform braking surface ... something
Mavic never got quite right until they started machining their rims.
R/ John
Rick Denney
wrote:
>Not so sure about that. The rims start out heavier and then they're
>machined down to spec (the new Open Pros are slightly heavier than the old
>Open 4CD's). It does provide a more uniform braking surface ... something
>Mavic never got quite right until they started machining their rims.
>
Huh? You can't have it both ways. Either the extrusion is uniform, or
it isn't. If the extrusion is uniform, then machining it cannot make
it moreso, and therefore it won't have a "smoother braking surface".
Or the extrusion is not uniform, in which case machining it will
create thin and thick spots. If such is the case and the rim starts
out light, then the thin spots provide early death opportunities. If
the rim starts out heavy to overcome that problem, then the thick
spots add weight unnecessarily.
I have some Reflex rims (machined) on my road bike and some MA-2's
(not machined) on my commuter. I can't tell the difference in
smoothness. When the Reflex rims die, I'll replace them with MA-2's.
Rick "Extrusions are uniform" Denney
Jobst Brandt
> The rims start out heavier and then they're machined down to spec
> (the new Open Pros are slightly heavier than the old Open 4CD's).
> It does provide a more uniform braking surface ... something Mavic
> never got quite right until they started machining their rims.
I don't know what advantage is gained by machining rims other than
expense, making the side walls variably thin and leaving little wear
margin. I have used more rims than I'd like to think of and have
never had any problem with the smoothness or continuity of the side
walls.
Jobst Brandt <jbr...@hpl.hp.com>
Matt O'Toole
Jobst Brandt <jbr...@hpl.hp.com> wrote in message
news:7dqsm9$3gb$1...@hplms2.hpl.hp.com...
You've been lucky. Many rims have sloppy joints. This causes the brake pad
to hang up slightly, which is rarely a real problem, but it is annoying. I
have such a rim on my bike right now. I would say that most cheaper rims
I've used have been this way. Many people probably started riding on a
cheaper bike with such rims. When finally buying a "good" bike, or "good"
wheels, they want assurance that they won't have this problem. So, in come
the machined rim salesmen, "You won't find any ripply joints here, our rims
are *machined* smooth!"
Of course, it would be better if they had just sawed the joints square and
pinned them straight, then left the sidewalls alone. But, their marketing
goons aren't smart enough to communicate that, so they fall back on the
machined rim crutch.
Matt O.
Jobst Brandt
>> I don't know what advantage is gained by machining rims other than
>> expense, making the side walls variably thin and leaving little wear
>> margin. I have used more rims than I'd like to think of and have
>> never had any problem with the smoothness or continuity of the side
>> walls.
> You've been lucky. Many rims have sloppy joints. This causes the
> brake pad to hang up slightly, which is rarely a real problem, but
> it is annoying. I have such a rim on my bike right now. I would
> say that most cheaper rims I've used have been this way.
I suppose we shouldn't compare low class rims to good ones. There's
no benefit in fixing up a poorly made rim any more than upgrading a
Walmart bicycle with top of the line equipment. The bicycle's
value rises minimally while the value of the components goes to near
nothing.
> Many people probably started riding on a cheaper bike with such
> rims. When finally buying a "good" bike, or "good" wheels, they
> want assurance that they won't have this problem. So, in come the
> machined rim salesmen, "You won't find any ripply joints here, our
> rims are *machined* smooth!"
This is similar to the popularity of the air cooled car in the 1950's
when people remembered boiling radiators of pre WWII vintage. What
they didn't notice is that the military perfected the water pump seal
during the war and post war cars didn't boil over anymore, yet one of
the main sales points was originally "-air cooling-",... something no
car should have anyway.
> Of course, it would be better if they had just sawed the joints
> square and pinned them straight, then left the sidewalls alone.
> But, their marketing goons aren't smart enough to communicate that,
> so they fall back on the machined rim crutch.
Rims do not need to be pinned, the joint never being stressed in any
direction but compression. You probably meant the alignment insert
that is pressed in firmly and guarantees a good fit. You'll notice
that no intelligent rims have weld or rivets to "hold them together".
Jobst Brandt <jbr...@hpl.hp.com>
Razoreye
RW- Rep of Tx
Jobst Brandt
> How does chroming the rims affect the brakes..... ETC?
Makes the rim as slick as snot in the rain. This produces the worst
brake surface one can imagine for a bicycle rim. Of course you could
sand blast the aluminum and mat finish chrome it, but that wears
smooth too, after a while.
Jobst Brandt <jbr...@hpl.hp.com>
Tim Smith
>This is similar to the popularity of the air cooled car in the 1950's
>when people remembered boiling radiators of pre WWII vintage. What
>they didn't notice is that the military perfected the water pump seal
>during the war and post war cars didn't boil over anymore, yet one of
>the main sales points was originally "-air cooling-",... something no
>car should have anyway.
Popularity? So how many air-ccoled cars were ever on-sale in the US?
Three, maybe? VW, Porsche, and the car-that-never-should-have-been:
the Corvair. Don't remember that VW ever tried to make a
marketing/advertising point of the lack of liquid--perhaps they did. I
always thought that it was "not there" as a simplicity/cost-cutting
measure in the peoples' car (water pumps, radiators, liquid, weight).
Interesting that the other European rear engine cars of the 50s (Fiat
600s, Renault 4CVs, and their ilk) were water-cooled (barely, in the
4CV case).
But you've been there, and would know the reason for it. I'm not so
sure it was marketing, but enlighten those of us who suffered 1950s
cars with more info.
--Tim (tss...@best.com)
CV2572
>You'll notice
>that no intelligent rims have weld or rivets to "hold them together".
You mean, of course, "...that no intelligently made rims ...."
I'm sure there are no 'smart' rims out yet ....
Robin Hubert
Jobst Brandt
>> This is similar to the popularity of the air cooled car in the 1950's
>> when people remembered boiling radiators of pre WWII vintage. What
>> they didn't notice is that the military perfected the water pump seal
>> during the war and post war cars didn't boil over anymore, yet one of
>> the main sales points was originally "-air cooling-",... something no
>> car should have anyway.
> Popularity? So how many air-cooled cars were ever on-sale in the US?
> Three, maybe? VW, Porsche, and the car-that-never-should-have-been:
> the Corvair.
The desire for air cooling in cars was always driven by a loathing for
geysers at the radiator (convection heat exchanger) or blowing out a
hose. What went unnoticed was the cause even to the bitter end of air
cooled cars, and that was the pump seal. That Porsche had air cooling
came from the name or its heritage. If Ferdinand Porsche designed it
(and he didn't) then it must be right. That is why the Porsche had a
rear engine and torsion bars, two other anomalies not seen on cars.
That Corvair imitated the VW was a belated "me too" attempt and I
think the man responsible for that one should have been fired for the
many failings of that car that were previously known for other
attempts.
> Don't remember that VW ever tried to make a marketing/advertising
> point of the lack of liquid--perhaps they did.
That was a major part of the initial sales pitch. With a car so
different, Madison Avenue had a field day coming up with wacky ads
that made features of many of the failings of the car. They
advertised how easy it was to remove the engine... it needed it. VW
shops always had engines standing around for one repair or another.
> I always thought that it was "not there" as a simplicity/cost-cutting
> measure in the peoples' car (water pumps, radiators, liquid,
> weight). Interesting that the other European rear engine cars of
> the 50s (Fiat 600s, Renault 4CVs, and their ilk) were water-cooled
> (barely, in the 4CV case).
That was the pitch but it isn't cheaper at all. The motor block is
made of two halves and four cylinder barrels whose thermal expansion
is a major failing of the engine. Besides, it is partly oil cooled,
having an oil cooler that sits inside the fan housing. This oil
cooler blocks air from reaching the left front cylinder and the air it
gets is pre-heated by the oil cooler. Hence, burned valves and scored
cylinders in CYL-3. The litany of blunders in that engine is lengthy.
> But you've been there, and would know the reason for it. I'm not so
> sure it was marketing, but enlighten those of us who suffered 1950s
> cars with more info.
The VW is the perfect vehicle to teach automotive designers what not
to do. It has inappropriate concepts from the tip of the front bumper
to the rear one. What made the car what it achieved was a dedicated
staff and a great service network with a nation of eager workers who
believed in their product. What they didn't have in the product they
had doubly in commitment at a time when the US auto industry was smug
in having won the war. Let them eat cake! was their motto.
Jobst Brandt <jbr...@hpl.hp.com>
Jobst Brandt
>> You'll notice that no intelligent rims have weld or rivets to "hold
>> them together".
> You mean, of course, "...that no intelligently made rims ...."
> I'm sure there are no 'smart' rims out yet ....
No, but I hear they have "active" rims, and that must be getting close
to intelligence (in the civilian sense).
Jobst Brandt <jbr...@hpl.hp.com>
Rick Denney
>
>The VW is the perfect vehicle to teach automotive designers what not
>to do. It has inappropriate concepts from the tip of the front bumper
>to the rear one. What made the car what it achieved was a dedicated
>staff and a great service network with a nation of eager workers who
>believed in their product. What they didn't have in the product they
>had doubly in commitment at a time when the US auto industry was smug
>in having won the war. Let them eat cake! was their motto.
>
What also made the car was that the poorly designed engine was grossly
underpowered. With a 6:1 compression ratio and 36 (or 40) horsepower,
the design had enough overhead to forestall problems. The reputation
for reliability came from these early 36-hp models. The later, more
powerful versions of the same engine were consistently unreliable. I
could add problems keeping the split case together to Jobst's list.
Anyone with performance intentions would start with an external oil
cooler (to get it out of the fan housing), and likely end up with Scat
replacement jugs, which were liquid-cooled.
Rick "Used to race against bugs" Denney
Jeff Sweeney
they comparable to the VW?
Ole Blokhus
>>> I guess that is why Mavic stopped putting it on the sides.
>Actually, Mavic has not stopped anodizing the braking surface of their rims.
>The blue Reflex rims that you have were machined *after* anodization.
>Current Mavic rims (Open Pro, Reflex tubular) are machined (SUP/Soude usine
>process!?) prior to anodization- if you look at a current rim the braking
>surface is also dark.
>HA rims are really for appearance only, and they do have a tendency to fail
>at the eyelet (although my personal experience with properly built HA rims
>is that they will "expend" themselves naturally before any eyelets
>fail/crack; but I am a relatively puny 145 lbs and ride smoothly)
>I have never used a ceramic rim, but at the shop we see that they eat
>through brake pads quickly, and are quite expensive.
They only eat brake pads when brand new. When the ceramic coating has become
polished shooth, brake pads tend to last much longer than with regular rims. A
friend used to go through a set of XTR v-brake pads in a couple rides. The
next season he got a new bike with ceramic rims, and he sold the brakes 6
months later with the original pads on them. The conditions were largely the
same both seasons.
Ole.
--
Ole Blokhus, Norway
ol...@powertech.no
Profession: Videotape Editor at the Norwegian Broadcasting Corporation (NRK)
Obsession: Using my money earned above on bikes, and then riding them.
Passion: That would be my SO.
Jobst Brandt
>> I have never used a ceramic rim, but at the shop we see that they
>> eat through brake pads quickly, and are quite expensive.
> They only eat brake pads when brand new. When the ceramic coating
> has become polished smooth, brake pads tend to last much longer than
> with regular rims. A friend used to go through a set of XTR v-brake
> pads in a couple rides. The next season he got a new bike with
> ceramic rims, and he sold the brakes 6 months later with the
> original pads on them. The conditions were largely the same both
> seasons.
Something seems to be wrong with this picture. Ceramic was intended
to improve wet braking, so it was made rough to penetrate the
lubricating boundary layer of water. For these rims, the cause of
brake pad wear is twofold, abrasive roughness and heat. Braking
converts kinetic energy (motion of the bicycle/rider) to thermal
energy, or heat. The heat is generated in the brake pad by material
deformation, it being the softer of the rubbing pair of materials, and
cannot dissipate as it should by conduction into the aluminum rim that
is insulated by the coating.
Insulating ceramic if smooth, is the worst of both conditions, not
working well when wet, and overheating brake pads when dry. This was
already achieved with hard anodized aluminum rims. What improvement
in braking do smooth ceramic rims promise, and if they are better, why
aren't they made smooth when new? Surface roughness can be controlled
in manufacture of these rims, as expensive as they are.
Jobst Brandt <jbr...@hpl.hp.com>
Tim Smith
This was true of most air-cooled engines that were designed in the
30s, 40s, and even the 50s. Triumph twin cylinder motorcycle engines
are a classic example. In their low-compression 500cc state, they were
no more unreliable than most other other mc engines of the era. Once
they started exporting them to the USA, bored them out to 650cc, and
upped the compression ratio to "take advantage" of higher-quality
gasoline in the USA, the problems appeared in great quantity. But
horsepower sells, and anyhow most motorcycles that were (are) sold in
the US are not intended for long, reliable service. A year or two at
most, until the owner gets bored with it all, and stores it in the
garage, or sells it to an unsuspecting teenager.
Unfortunately, there are parallels here with the current bicycle
market. When fashion (and magazine-induced bragging rights) become
more important than serviceability, function, and dependability, you
get the trash that infests the market today. The modern bicycle is not
designed for long-term use, or transportive functionality. It's just a
fashion statement.
--Tim (tss...@best.com)
Ole Blokhus
I agree with your points, but there are other factors at play here. For
mountain biking, the main benefit of ceramic isn't braking power, but rim
longevity. Riding off road in wet conditions will eat through a rim in a few
months.
Even if polished smooth, the ceramic rims seem to stop better than plain rims
when it's wet and dirty. It seems that the water/aluminum-oxide goo on a
regular rim reduces friction more than the plain water on a ceramic coated
one. When it's dry, I can't say that I notice much difference between the two.
Other than that the brake pads on my bike with ceramic rims last much longer.
If you look at Mavic's old 217 rims, they had a very rough ceramic coating.
With the never x517, they didn't bother, it has an almost smooth coating,
causing a lot less wear, but still stopping well. The rough coating was awful
when dry, and I hated my 217s until they finally broke in. (became smooth)
For my riding conditions, ceramic has proven to be the better choice. It's wet
most of the time, and the off-road decents are neither long nor steep enough
to cause noticable problems with overheating pads. I agree that with the
higher speed one usually experiences on a road bike, this could indeed be a
problem.