Chalo wrote in message <
[email protected]>...
>"Trevor Jeffrey" <[email protected]> wrote:
>>
>> Cup &cone bearings have an inherent adjustment, cartridge
>> bearings do not.
>
>Properly designed, hubs using cartridge bearings never need
>adjustment, ever. Calling this a shortcoming is like saying clinchers
>are inferior to tubulars because you can't sew them or glue them .
You should have used something better than this. Correctly designed
cartridge hubs have a weight penalty to bear due to the requirement of a
stiffer axle and hubshell than cup &cone. They also require a special
removal tool at greater frequencies than it is required to disassemble
cup&cone. Wired on tyres are inferior to tubulars for many reasons including
cost. The benefits of using tubs far outweigh their perceived hassle. They
are different, with practice the skill is learnt and becomes easy. Being
sewn and glued on the rim is an advantage with a puncture and I am
descending
a hill in excess of 60mph.
>
>> Cup &cone allows for the frequent replenishment of lubrication along
>> with the removal of damaging debris, cartridge bearings do not.
>
>Cup & cone bearings, due to their poorly aligned nature, frequently
>allow contaminants past their seals, if they even have any seals.
>Therefore they must allow periodic disassembly for cleaning.
The nature of the design allows misalignment in the sense of what is
required for a cartridge bearing. As a c&c remains a c&c and does not want
to imitate a bearing from a washing machine motor it does exceptionally well
despite your unfounded criticisms. Periodic disassembly is not required, a
drop of oil every 1000 miles is all that is required. The oil migrates out
between the dustcap and cone taking any debris including wear particles with
it. This facility is not available in a sealed cartridge bearing, the seal
trapping in the wear particles to cause a relatively early demise to the
bearing. Unfortunately sealed cartridge bearings do not keep contaminants
out, water in contact with the bearing seal will creep into the bearing and
quickly cause corrosion. The reason being that only small amounts of grease
lubrication are used and the antioxidant wears out relatively quickly.
>
>> Cartridge bearings are susceptible to damage due to misalignment.
>
>Cartridge bearings sit in precision-cut bores where they are only
>subject to misalignment in the case of a bent axle. Because they do
>not depend on an external axle thread for alignment, they can use an
>externally smooth axle, or one of larger major diameter than a
>conventional axle, or both, thus effectively preventing axle bending.
C&c could be precision made, why waste money? The precision required
involves three cuts for a properly manufactured cartridge bearing hub rather
than the single cut and bang in the cup on a c&c system. Again the hubshell
has to be stiffer, so heavier. The use of a larger diameter axle not only
increases weight but reduces the available bearing space and so small balls
and greater rolling resistance. It is not possible to prevent axle bending
within reasonable sizes it is only possible to reduce it. Cartridge
bearings generally used in bicycles need accurate, to the extreme, alignment
because of the four point contact ball.
>
>> Cartridge bearings are generally sealed for life which gives them
>> a finite lifespan, which requires periodic replacement.
>
>Cup & cone bearings typically admit more contaminants and always
>feature looser tolerances than industrial bearing cartridges, which
>gives them a finite lifespan. When they fail, they usually cannot be
>replaced and must either be cobbled back together in a damaged state,
>or discarded along with the wheel they are embedded in. This is in
>contrast to cartridges, which are simply removed and replaced with
>new, often for less than the price of new high-quality bearing balls
>for a cup & cone hub.
Cup &cone will admit more contaminants than industrial cartridge bearings
because cup and cone are found on bicycles where water is usually a major
factor(fair weather only cyclists do not apply here) and industrial
cartridge bearings of the sealed type are found on electric motors hopefully
without water splashing over their armatures. The c&c design copes
admirably with the problem due to its great capacity for an excess or
reservoir of lubricant in the form of oil saturated grease. When kept in
this state no stripping down or replacement is needed. They do not fail if
kept wet with lubricant containing antioxidant. At a bearing stockist 5000
balls were less than two small sealed bearings.
>
>> Sealed cartridge bearings have the drag of the seal. The loading
>> taken by a wheel means that the rolling resistance of a similarly sized
>> bearing is greater in a cartridge bearing due to smaller balls and four
>> contact points per ball instead of two.
>
>This would be true if the dimensional tolerances were similar between
>cup & cone Vs. cartridge bearings. They are not. Ordinary cartridge
>bearings being industrially standardized and graded, they feature
>finish and dimensions typically 10X more accurate than average cup &
>cone parts, and assembled concentricity roughly 100X better. You can
>feel the difference in your fingertips when you turn an axle from one
>of each kind of hub.
I don't know of any one who rides a bike with their fingertips. I might
as well say that this monitor in front of me has a screen 1000 times
smoother than a piece of paper, so I type better than I write. Anyone know
whether smooth paper improves handwriting? cartridge bearings deteriorate
faster than cup and cone and their rolling resistance is higher at all
stages of life than a smooth cup and cone bearing using loads found in cycle
bearings.
Industrially standardized also means one size fits all, you get what
your given. No thanks, give me the component designed for the job with 120
years usage to back it up.
>
>> Conclusion: Cartridge bearings are good for the bike shop.
>
>This would be true if most bike shops did a more thorough job of
>stocking bearing cartridges, and if cartridge bearing replacement were
>more difficult for the end user to do. As it is, there are industrial
>bearing retailers in practically every city, and bearing replacement
>can be done quickly and easily by a non-expert mechanic using
>ordinary, non-bike-specific tools.
If it requires ordinary tools to replace, the accuracy of fit is poor and
that is why it has worn and needs replacement, otherwise its 2 years old,
the antioxidant has expired and the bearing has got wet. Mechanics still
need to be skilled. Expert and professional I consider superfluous.
Rest of Chalo's post cut due to its repetition and my need of sleep.
4am utc
11:30 utc
As a sealed cartridge bearing in not designed for human powered
transport where weight is an issue, it is inappropriate to consider it for
this application.
The sizing of a typical hub does not allow an adequate size of cartridge
type bearing for the load and speed involved.
A peculiarity of cartridge bearings is that they are designed for a much
higher speed than that involved in a bicycle wheel. The stop, start and
slow conditions encountered are not catered for by the lubricant in a
standard sealed cartridge bearing. If one of the seals was broken and the
grease replenished with something more suitable for the slow nature of a
bicycle wheel then a longer service life would ensue. Not so simple
anymore, is it?
TJ