Rohloff makes the case for Cyber Nexus

On Apr 28, 2:19*pm, Andre Jute wrote:
On Apr 28, 9:19*pm, pm wrote:

But hill inclination and vehicle accelerations are quite separable, by
filtering in software. Vehicle accelerations have no DC component to
speak of. Today's solid state accelerometers are stable enough to make
it easy to tell these signals apart. It is part of the strategy used
by the iBike power meter, for example.

-pm

Are you saying that inclination is derived from speed by the CPU?

No, you would at least need an acceleration sensor; I was saying that
it's practical to do so even in the presence of other various motions
on the bike, and the appropriate accelerometers are very cheap
nowadays, being employed as tilt sensors in cell phones, lockouts in
laptop hard drives, video game controllers and so on. I don't know
whether any of them live in that Cyber Nexus CPU unit, but the iBike
power meters combine a solid state accelerometer with a speed sensor
(among other sensors) to derive inclination (among other data.)

On Apr 29, 2:12*am, pm wrote:
On Apr 28, 2:19*pm, Andre Jute wrote:

On Apr 28, 9:19*pm, pm wrote:

But hill inclination and vehicle accelerations are quite separable, by
filtering in software. Vehicle accelerations have no DC component to
speak of. Today's solid state accelerometers are stable enough to make
it easy to tell these signals apart. It is part of the strategy used
by the iBike power meter, for example.

-pm

Are you saying that inclination is derived from speed by the CPU?

No, you would at least need an acceleration sensor; I was saying that
it's practical to do so even in the presence of other various motions
on the bike, and the appropriate accelerometers are very cheap
nowadays, being employed as tilt sensors in cell phones, lockouts in
laptop hard drives, video game controllers and so on. I don't know
whether any of them live in that Cyber Nexus CPU unit, but the iBike
power meters combine a solid state accelerometer with a speed sensor
(among other sensors) to derive inclination (among other data.)

Thanks. I'll look into it the next time I have that bike up on the
stand, with the RS (electronics supply house) catalogue open beside
me, see if I can spot the chip to report its number to Bernard who has
dreams of DIY.

Andre Jute
Visit Jute on Amps at
http://www.audio-talk.co.uk/fiultra/
"wonderfully well written and reasoned information for the tube audio
constructor"
John Broskie TubeCAD & GlassWare
"an unbelievably comprehensive web site containing vital gems of
wisdom"
Stuart Perry Hi-Fi News & Record Review

Per RonSonic:
Humans can anticipate the need to shift so there's no need to count seconds.

Am I the only one that likes to roll up 4-5 gears occasionally
just to get out of the saddle and give my butt a break?
--
PeteCresswell

"(PeteCresswell)" wrote in message
...
Per RonSonic:
Humans can anticipate the need to shift so there's no need to count
seconds.

Am I the only one that likes to roll up 4-5 gears occasionally
just to get out of the saddle and give my butt a break?

Nope - isn't it a fairly standard technique on long hills too?

"Andre Jute" wrote in message
...
On Apr 29, 2:12 am, pm wrote:
On Apr 28, 2:19 pm, Andre Jute wrote:

On Apr 28, 9:19 pm, pm wrote:

But hill inclination and vehicle accelerations are quite separable,
by
filtering in software. Vehicle accelerations have no DC component to
speak of. Today's solid state accelerometers are stable enough to
make
it easy to tell these signals apart. It is part of the strategy used
by the iBike power meter, for example.

-pm

Are you saying that inclination is derived from speed by the CPU?

No, you would at least need an acceleration sensor; I was saying that
it's practical to do so even in the presence of other various motions
on the bike, and the appropriate accelerometers are very cheap
nowadays, being employed as tilt sensors in cell phones, lockouts in
laptop hard drives, video game controllers and so on. I don't know
whether any of them live in that Cyber Nexus CPU unit, but the iBike
power meters combine a solid state accelerometer with a speed sensor
(among other sensors) to derive inclination (among other data.)

Thanks. I'll look into it the next time I have that bike up on the
stand, with the RS (electronics supply house) catalogue open beside
me, see if I can spot the chip to report its number to Bernard who has
dreams of DIY.

Couldn't the suspension behaviour be rather simpler explained by speed? Most
people slow down for a hill, therefore it only has to notice that. I
wouldn't mind riding one to see how it actually behaves, but that isn't
going to happen...

On Tue, 28 Apr 2009 21:53:35 -0400, "(PeteCresswell)" wrote:

Per RonSonic:
Humans can anticipate the need to shift so there's no need to count seconds.

Am I the only one that likes to roll up 4-5 gears occasionally
just to get out of the saddle and give my butt a break?

Nope. As far as I know, everybody does that and everybody spending and hour or
more on the bike probably should. Or mix standing and sitting on a long climb,
we do that too. I have no idea how the automatics respond to that sort of thing.

Clive George wrote:
Speed, inclination and gear together give effort, indirectly as
I said.

...only if you neglect wind resistance.

I think it's just speed and gear it plays with - doesn't need to
be any more complicated than that.

20km/h at level ground might be 50W or 200W with the same gear,
depending on wind...that doesn't cope with the "fixed effort" claim.

--
MfG/Best regards
helmut springer panta rhei

Andre Jute wrote:
Speed, inclination and gear together give effort, indirectly as
I said.

...only if you neglect wind resistance.

If there is a headwind, the cyclist slows down and the CPU puts
him in a lower gear so that his effort is the optimum he selected.

So the cyclist regulates effort, not the system which just regulates
cadence. No need for inclination measures then.


If there is a tailwind the cyclist travels faster and CPU puts him
in a higher gear and his effort again is the optimum he targets.
This is exactly the same concept as a racing cyclist changing
gears to maintain his cadence, which is his optimum energy
expenditure.

You confirm: it's just fixed cadence. And of course "optimum
energy" cadence changes with parameters and time, comfort being one
of them.

--
MfG/Best regards
helmut springer panta rhei

On Apr 29, 8:59*am, Helmut Springer wrote:
Andre Jute wrote:
Speed, inclination and gear together give effort, indirectly as
I said.

...only if you neglect wind resistance.

If there is a headwind, the cyclist slows down and the CPU puts
him in a lower gear so that his effort is the optimum he selected.

So the cyclist regulates effort, not the system which just regulates
cadence. *No need for inclination measures then.

If there is a tailwind the cyclist travels faster and CPU puts him
in a higher gear and his effort again is the optimum he targets.
This is exactly the same concept as a racing cyclist changing
gears to maintain his cadence, which is his optimum energy
expenditure.

You confirm: it's just fixed cadence. *And of course "optimum
energy" cadence changes with parameters and time, comfort being one
of them.

A very similar concept, yes. There is a desired effort dial which is
essentially set after a little experimentation and forgotten. That's
equivalent to cadence.

Then there are various programmes for the gearbox under the cyclist's
thumb which according to setting changes up sooner or later: Normal
(which Shimano calls D for Drive), Little Old Lady (L for Leisurely)
which is very low and hangs on to the low gears forever, and Sport
(I've forgotten the symbol but Fogel will look it up for us), which
cuts out first gear altogether and changes up much more quickly to put
you in the highest gear very quickly. That's adaptation to
circumstances.

Soon I left the box in Sport because that's my style of riding anyway.

What surprises me is that no one wants to talk about the
electronically adaptive Di2 fork, which is very, very impressive; it
would be a most superior fork for a loaded tourer or a fast commuter
even without the electronic control. It's pretty hard even at its
softest setting but gets better as you speed up, and its control,
compared to say the oversoft RST fork on my Gazelle (itself a sporting
model and thus presumably harder sprung than the common or garden
commuters), is an absolute eye-opener. It's the only suspended fork on
which I've ever felt I didn't have to make allowances around some of
the fast corners in the lanes around here.

Andre Jute
Visit Jute on Bicycles at
http://www.audio-talk.co.uk/fiultra/...20CYCLING.html

"Helmut Springer" wrote in message ...
Clive George wrote:
Speed, inclination and gear together give effort, indirectly as
I said.

...only if you neglect wind resistance.

I think it's just speed and gear it plays with - doesn't need to
be any more complicated than that.

20km/h at level ground might be 50W or 200W with the same gear,
depending on wind...that doesn't cope with the "fixed effort" claim.

That's because it is not truely automatic. The shifting is automatic within preset ranges. The rider as three ranges to choose from so he/she can approximate to "fixed effort" Here is a quote from the manual:

"When riding up slopes or into headwinds and pedaling becomes more difficult, press the switch to shift to the L mode.If pedaling is too fast, press the switch to shift to D or Ds mode."

Graham.