[rollei_list] Re: Bikes
- From: Jerry Lehrer <jerryleh@xxxxxxxxxxx>
- To: rollei_list@xxxxxxxxxxxxx
- Date: Thu, 08 Jun 2006 17:06:49 -0700
FRANK,
I believe that B und O used the Be thin film to increase
the cone stiffness without increasing the mass.
Beryllium is used for orbital structures for it's stiffness.
I used a scrap piece of tubing to make the tone arm.
Be is a very dangerous material with which to work. The
swarf can lead to berylosis, which is incurable.
Jerry
FRANK DERNIE wrote:
> Hi Jerry,
> I knew Be was outside the norm but did not realise it
> was a factor of 6. Hans Metzger told be about trying
> coated Be discs on the braking system of the sprint
> version of the 917 - they never got them to work
> though I don't know why. There are Be vapor deposited
> domes on the speakers I use in my bedroom!
> cheers
> Frank
>
> --- Jerry Lehrer <jerryleh@xxxxxxxxxxx> wrote:
>
> > Frank,
> >
> > Most all structural metals have identical specific
> > stiffness, EXCEPT
> > Beryllium, whose specific stiffness is 6 times
> > higher. Tubular beryllium
> >
> > replaced the aluminium tone arm shaft on my Linn
> > Itok tone arm.
> >
> > Jerry
> >
> > Frank Dernie wrote:
> >
> > > I know nothing about bikes but I am very familiar
> > with these
> > > materials. Steel and Ally have more or less
> > identical specific
> > > stiffnesses so any difference will be due to the
> > geometry - for
> > > example the larger diameter tubes used in the ally
> > frame for strength
> > > will result in stiffer welded junctions. Carbon is
> > nothing like either
> > > steel or ally. The mechanical properties depend on
> > the layup and
> > > material choice, there is a huge variation in
> > stiffness of different
> > > fibres unlike metals where the strength can vary
> > greatly between
> > > alloys but the stiffness not much at all. The
> > fibre orientation and
> > > type of fibre will have a much bigger effect in
> > carbon than metal
> > > though the geometry of the joints will have the
> > biggest influence on
> > > stiffness. Carbon can have significant internal
> > damping, depending on
> > > resin system. Metals have negligible internal
> > damping.A carbon frame
> > > has more potential than a metal one, I would
> > expect an optimised
> > > carbon frame to cost between 10 and 100 times more
> > than a metal one so
> > > they probably either don't exist or the metal ones
> > are much more
> > > profitable :-)Frank On 8 Jun, 2006, at 02:18,
> > Douglas Nygren wrote:
> > >
> > >> One further thought about bikes that pertains to
> > cameras.
> > >>
> > >>
> > >>
> > >>
> > >> New developments in bike design and construction
> > have led to many
> > >> carbon fiber (ie. plastic) and aluminum bikes.
> > They have displaced
> > >> the old standard whcih were made of metal, often
> > called
> > >> "Cro-malloy."
> > >>
> > >>
> > >>
> > >> The carbon and aluminum bikes are lighter. Some
> > are more rigid than
> > >> the steel. They climb well, but they don't
> > descend as well. They hop
> > >> with every bump. The steel absorbs this better.
> > On a long ride, the
> > >> aluminum beats the rider up. They are so stiff
> > that the very quality
> > >> that allows them to climb better--ie. the
> > stiffness that transfer
> > >> the energy better--also allows the energy from
> > bumps to return
> > >> upward and into the rider. On a long ride, this
> > does a number on the
> > >> rider. Steel treats the rider better.
> > >>
> > >>
> > >>
> > >> I think you'd be hard pressed to find a steel
> > bike on the Tour de
> > >> France these days. Carbon is in, and it's a lot
> > like aluminum.
> > >>
> > >>
> > >>
> > >> I perfer steel, and I prefer film to digital. I'm
> > afraid I'm
> > >> becoming anachronistic.
> > >>
> > >>
> > >>
> > >> Doug
> > >
> > >
> >
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> > > 06/06/2006
> > >
> >
>
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