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Message-ID: <WJ_ba.583$>
Date: Thu, 13 Mar 2003 12:22:14 GMT

Nicholas Grieco writes:

>>  Noise is a gratuitous error in design, the silent, cheap, and
>>  durable ratchet having been invented long ago...

> Is the click of each ratchet tooth actually louder, or simply more
> frequent?  To my ear, it's the latter.  The sound is an acquired
> taste, at best, and I just keep pedaling.

Well, I should qualify that statement.  The reason for all these "new"
freewheel ratchets is that the sprocket bodies are being made of
aluminum to save weight.  Aluminum is insufficiently strong to have a
conventional ratchet inside the sprocket carrier so all sorts of
ratchets with more strength are being tried, some having no advantage.

The problem with all this is that a sprocket carrier of aluminum is
also too weak to carry sprockets that dig into the splined body up to
failure.  OH!  Why didn't someone test this or at least make a
calculation?  This whole gram shaving at great cost is so stupid, it
reminds me of the drillium craze of the 1970's.  Everything was drilled
full of holes, even things that could not work that way.

>> I don't want to pay money for such trivia.

> More important:  Chris King Cycle Group appears to be one of the more
> environmentally and socially responsible companies around.  There's
> something to be said for a company that designs and manufactures its
> products in house, and which assumes responsibility for both the
> longevity of its product, and the environmental impact of its
> manufacturing byproducts.

What you mean "designs its products in house" how else do you design
products?  And what is "the environmental impact of its manufacturing


I think you got overwhelmed by the hype on that web site:

   "This two building facility was entirely custom designed and built
    to support all of our manufacturing processes (we do everything in
    house) as well as our philosophies of work place design and near
    fanatic environmental consciousness."

I guess that means they have an indoor toilet.  To call this
philosophy is a stretch of the term.  Webster's sees it otherwise:

   "(1) : all learning exclusive of technical precepts and practical
    arts (2) : the sciences and liberal arts exclusive of medicine,
    law, and theology <a doctor of philosophy>"

Jobst Brandt
Palo Alto CA

Message-ID: <QG9ca.678$>
Date: Fri, 14 Mar 2003 00:49:52 GMT

David L. Johnson writes:

>> I'm going to take one apart just for the learning experience.  But,
>> like Jobst said, they can be silent and still do their job.

> I think he was referring to clutch mechanisms designed to be silent.
> But a true ratchet that is silent is a ratchet that is fouled with
> something, and could easily fail.

Not so.  Since I still ride antique equipment, you cannot hear the
freewheel even when I raise the back end and give the rear wheel a
spin with the pedals.  I've been riding this kind of ratchet all of my
bicycling days, first by Regina and then Sun Tour, both with the same
type of bifurcated large pivot pawls, sprung by a single
circumferential spring-wire.  The advent of this pawl was the first of
many silent freewheels.

Before those, the Regina Gran Sport, with individual hair springs,
could be made silent by de-cambering the springs.  This was a regular
exercise before the 1970's.

What most engineers who design these things today don't realise, is
that through elasticity of the parts, only one facet or pawl carries
the entire load for part of a rotation.  A free body diagram can make
that unambiguously clear.  For that reason Regina used a ratchet with
21 steps and two diametrically displaced ratchets to give 42 clicks
per revolution.  The dual and triple pawl engagement ultimately fails
because its distributed load bearing relies on faultless zero
clearance bearing adjustment, something that is possibly true when new
but not thereafter.

I suspect the "engineers" in the bicycle business are not engineers
but always wanted to be a bicycle mechanic and "now I are one," as
they say.  The public is the product test medium.

Jobst Brandt
Palo Alto CA

Message-ID: <BDVca.1311$>
Date: Sun, 16 Mar 2003 07:23:13 GMT

Nicholas Grieco writes:

>>> Any individual sprocket that runs directly on the aluminum freehub,
>>> especially larger ones, dig in and are hard to remove at times.

>> This also happens on certain stainless steel freehub bodies made in
>> California.

> If you claim stainless steel drive shells are failing in the same
> manner as aluminum ones, then you could be suggesting there is a
> more fundamental problem in the design of the sprocket carrier.

> What have you found other manufacturers doing that is different in
> this area, to circumvent the problem you observe?

That means the stainless ones are not hardened sufficiently.  Besides,
hardening stainless steels are more expensive.  Case hardened carbon
or alloy steel shells can and have sustained these loads with no
damage.  Next, we'll see titanium or even carbon fiber shells and the
"tifosi" will go gaga over them at $200 each.

Jobst Brandt
Palo Alto CA

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