Rohloff makes the case for Cyber Nexus

Hi,

Andre Jute wrote:
Sorry to disappoint you, Bernard, but if you change "beforehand" there
will be several meters where you and the bike do not operate at
maximum efficiency. No human an react as fast as electronics.

Don't you ever coast? When slowing down due to the road changing from
straight to small curves or uphill? That's the perfect time to
gear-change, so you are in the right gear just when you need it ;-)

Whether it matters is a question of whether the extra weight overall
slows you down more than you gain with the perfectly optimum gear
changes. I wouldn't know; I ride a different style of bike and in a
different way (I control effort with a heart rate monitor, not by
speed or cadence).

See, I don't own a heart-rate device, though I watch my cadence. My
effort-control is fully on a as-I-like-it-right-now basis though I do
watch the actual force applied to the cranks via cadence (due to knee
problems)... Completely different riding style ;-)

Actually, you do have a cadence-monitor, too - it's in your Nexus ;-)

Mostly I feel my gear changes are optimal... So are yours...

Shimano's Cyber Nexus in its full flowering comes in two versions, one
for hub gears, one for derailleur gears. Both have fully auto and

Is there one for SRAM derailleurs? Because I do like my SRAM *much*
better than the old Shimano one. Personal thing ;-)

Oops, my next bike will quite likely have a SRAM DualDrive - please
don't tell me Nexus works with that?

Apart from that, my derailleur system is set up beyond spec - I have
smaller chainrings and larger sprockets than the manual allows for.
Would that work with Shimano's Nexus? Or do you have to use the special
Nexus sprockets? (Or Dura-Ace whatever?) Nexus sure ain't built for
out-of-spec use...

electronically assisted manual modes. Neither gruppo was ever sold at
retail to the public as far as I know. Gazelle still sells a version
....

See, my bike is self-built with all parts bought retail. Where can I
buy? It's not the technology, but the availability and compatibility
that's the problem...

Shimano also makes a cut-down version of the Cyber Nexus for racers;
it is part of one of the Dura-Ace gruppo. It is battery-powered rather
than dynohub powered, and all it does is electronically assisted
shifting, no full-auto mode.

Nice, but (a) the only thing I do hear about it is that it exists and
(b) it sure ain't compatible with SRAM components? Again, it is not the
technology that prevents me from using it...

There are hints that you're thinking of a do it yourself electronic

Not if I can avoid it ;-) I'd rather spend the time riding my bike than
building fragile and cumbersome gizmos... It's difficult enough to get
the chainrings I want...

system. The Shimano system is superbly efficient but depends on
proprietary parts, like a stepper motor sitting on the hub gearbox to
do the actual shifting. When I gave automating my Rohloff hub some
thought, I concluded that two stepper motors in the place of the
rotary control, each operating one cable, would give me electronically
assisted shifting. From experience with my Trek Cyber Nexus, I am not
impressed with electronic cables led to the rear hub, so if I ever do
it (no present plans; I'm waiting to see if my Rohloff runs in or I
get more used to it), I will leave the bowden cables to the handlebar
and simply slide the rotary control away a couple of inches, mount the
stepper motors in/on it, and put a toggle switch in its place under my
thumb, with a short cable to the stepper motors.

Sorry, I don't see the logic in your solution. I would want to do away
with the bowden cables (except for a few centimeter from servo to
derailleur). There is no problem at all with electric cables, if done
right. They don't freeze, rust, stick or elongate. I even thought about
replacing the bulk of the cable with a hydraulic system, like the Magura
rim brakes...

And concerning the Rohloff hub - it is said to be the very best shifting
there is - I'm sure it does out-perform your Nexus hub mechanically.
Apart from the user interface, where I do think you'll be more
comfortable with the Nexus ;-)

I don't think you can build any DIY system as cheaply as you can buy a
Shimano readymade system, unless you are already into electronics and
....

If you can buy - and use - the Shimano system at all. You'll be doing a
*lot* of searching if you want to buy a brand-new Cyber-Nexus (which
seems to have been out of production for quite a while)... And - as
stated - you won't be able to combine it with non-Shimano components.

I wasn't even able to combine a Shimano chainring with a Shimano
crank-set, at least not without grinding...

So I don't suppose, I'll be able to use the Shimano system for my bike
anyway. Still, I do see the benefit of shifting with electrical assist.
But I don't see a solution ready for my use...

Anyway, have fun with it...

Hi,

Andre Jute wrote:
There's a speed sensor in the dedicated hub dynamo of Shimano's Cyber

Seems sensible.

Nexus gruppo, and an inclination sensor somewhere. The central

Are you sure? I would rather suspect a cadence sensor in the custom
bottom bracket. Looking at the Cyber-Nexus images, the bottom bracket
really seems special...

The rest is just a bit of electronic computation... Any standard
cyclometer has enough calculating power for that...

Ciao...

Hi,

RonSonic wrote:
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.

Though I wouldn't suggest standing up on a fully loaded travelling or
freight bike. You simply won't be able to keep it upright... You do need
the contact to the saddle to balance the thing...

For all those "light" bikes, I'd agree, though...

Ciao..

Bernhard Agthe wrote:
Though I wouldn't suggest standing up on a fully loaded travelling
or freight bike.

BTDT.

You simply won't be able to keep it upright...

IBTD.

--
MfG/Best regards
helmut springer panta rhei

On 4/28/2009 2:25 PM Andre Jute wrote:

On Apr 28, 9:22�pm, Mike Rocket J Squirrel
wrote:
On 4/28/2009 11:10 AM Andre Jute wrote:



On Apr 28, 6:31 pm, Helmut Springer wrote:
Andre Jute wrote:
Speed, inclination and gear together give effort, indirectly as I
said.
...only if you neglect wind resistance.
--
MfG/Best regards
helmut springer panta rhei
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. 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.
Well, regardless of how it gets its smarts, it sounds like it might be fun
to ride a bike with one of these things.

I hated derailleurs: obstructive, dirty, fragile, nasty, grinding
leftovers from a more brutal age. Hub gears are the coming thing, and
the best hub gears are definitely automatic. (I haven't tried
Fallbrook's NuVinci CVT.)

But it isn't about fun, really. After a while you don't notice that
you don't change gears. You just treat the bike like a singlespeed.
You get on and ride, and the electronics do the rest perfectly
unobtrusively. The girlfriend of one the local fixie boys said to me,
"You must have hamstrings from hell to ride a one-gear bike up that
hill." She was quite disappointed to hear I had the assistance of Mr
Shimano's autobox.


Well, perhaps one day I'll have the opportunity to try one-a these new hubs.

I wonder whether auto hubs will become so pervasive that only the really
interesting women will still ride a "manual."

--
Mike "Rocket J Squirrel"
Bend, Oregon

On Apr 29, 10:07*am, Bernhard Agthe wrote:
Hi,

Andre Jute wrote:
Sorry to disappoint you, Bernard, but if you change "beforehand" there
will be several meters where you and the bike do not operate at
maximum efficiency. *No human an react as fast as electronics.

Don't you ever coast? When slowing down due to the road changing from
straight to small curves or uphill? That's the perfect time to
gear-change, so you are in the right gear just when you need it ;-)

Coasting is for wimps. When I coast, my agent calls me to remind me
how valuable his time is, and since his time is ten per cent as
valuable as my time... First mobile phone I ever owned, I threw in a
ditch when the ******* told me he was running in Central Park and
admonished me to get out and get some fresh air. I threw the phone
into the ditch where it sizzled most satisfactorily.

Whether it matters is a question of whether the extra weight overall
slows you down more than you gain with the perfectly optimum gear
changes. I wouldn't know; I ride a different style of bike and in a
different way (I control effort with a heart rate monitor, not by
speed or cadence).

See, I don't own a heart-rate device, though I watch my cadence. My
effort-control is fully on a as-I-like-it-right-now basis though I do
watch the actual force applied to the cranks via cadence (due to knee
problems)... Completely different riding style ;-)

Actually, you do have a cadence-monitor, too - it's in your Nexus ;-)

Mostly I feel my gear changes are optimal... So are yours...

Shimano's Cyber Nexus in its full flowering comes in two versions, one
for hub gears, one for derailleur gears. Both have fully auto and

Is there one for SRAM derailleurs? Because I do like my SRAM *much*
better than the old Shimano one. Personal thing ;-)

Oops, my next bike will quite likely have a SRAM DualDrive - please
don't tell me Nexus works with that?

Shimano had some kind of a dual-drive that came and went; I think
there was some difficulty making it work well.

Apart from that, my derailleur system is set up beyond spec - I have
smaller chainrings and larger sprockets than the manual allows for.
Would that work with Shimano's Nexus? Or do you have to use the special
Nexus sprockets? (Or Dura-Ace whatever?) Nexus sure ain't built for
out-of-spec use...

electronically assisted manual modes. Neither gruppo was ever sold at
retail to the public as far as I know. Gazelle still sells a version

...

See, my bike is self-built with all parts bought retail. Where can I
buy? It's not the technology, but the availability and compatibility
that's the problem...

Never mind availability. You're never going to get that far. The Nexus/
Nexave gruppo work with each other but I reckon making them work with
anything else will take machining i.e. quite a bit of money, with no
guarantee of success.

There is the option of a Nexus hub gear and a two or three ring front
but a chain tensioner loses one of the advantages of the Nexus, being
able to use a fully enclosed chaincase.

Another option is a Nexus with a Schlumpff Speed Drive twospeed box in
the bottom bracket but that used to require machining the frame (it
is possible it no longer requires machining) and doesn't give you
quite double the gears as there is some duplication; Florian Schlumpff
has some tables on his netsite that will repay careful study.
Depending on the cost of the machining, a Rohloff even at Rohloff
prices starts to look attractive...

Shimano also makes a cut-down version of the Cyber Nexus for racers;
it is part of one of the Dura-Ace gruppo. It is battery-powered rather
than dynohub powered, and all it does is electronically assisted
shifting, no full-auto mode.

Nice, but (a) the only thing I do hear about it is that it exists and
(b) it sure ain't compatible with SRAM components? Again, it is not the
technology that prevents me from using it...

There are hints that you're thinking of a do it yourself electronic

Not if I can avoid it ;-) I'd rather spend the time riding my bike than
building fragile and cumbersome gizmos... It's difficult enough to get
the chainrings I want...

system. The Shimano system is superbly efficient but depends on
proprietary parts, like a stepper motor sitting on the hub gearbox to
do the actual shifting. When I gave automating my Rohloff hub some
thought, I concluded that two stepper motors in the place of the
rotary control, each operating one cable, would give me electronically
assisted shifting. From experience with my Trek Cyber Nexus, I am not
impressed with electronic cables led to the rear hub, so if I ever do
it (no present plans; I'm waiting to see if my Rohloff runs in or I
get more used to it), I will leave the bowden cables to the handlebar
and simply slide the rotary control away a couple of inches, mount the
stepper motors in/on it, and put a toggle switch in its place under my
thumb, with a short cable to the stepper motors.

Sorry, I don't see the logic in your solution. I would want to do away
with the bowden cables (except for a few centimeter from servo to
derailleur). There is no problem at all with electric cables, if done
right. They don't freeze, rust, stick or elongate. I even thought about
replacing the bulk of the cable with a hydraulic system, like the Magura
rim brakes...

Shimano, possibly to allow OEMs to cut cables to length, made plug-in
cables for their Cyber Nexus. But I wouldn't want fragile electrical
cable firmly attached either. I don't mind if a stick, or a boot, rips
out a plugged cable, but a cable screwed down or soldered in can do
more damage than just to itself when ripped out. So, on balance, I
like bowden cables as they're already there and known to work, and
just to attach the stepper motors to their ends. On the Rohloff, I
suppose you could you could put the stepper motors near the hub and
connect them with short cables or possibly (with machining, perhaps)
with short stiff rods to the units operated by the cables.

And concerning the Rohloff hub - it is said to be the very best shifting
there is -

Whoever said that has never ridden one. The shifting is wretched by
comparison to a Nexus, agricultural hick shifting versus refined city
slicker shifting. I think that what you mean is that the Rohloff is
the very best hub gearbox there is, which I too think is true. But
it's user interface is the very worst thing about it.

I'm sure it does out-perform your Nexus hub mechanically.

Oh yes. I bought the Rohloff to get more gears when I moved to a house
at the top of a steep hill. And the Rohloff is definitely a gearbox
for the ages whereas the Nexus is built to a price and probably has a
finite lifespan. Not that it matters to me because I don't ride
anywhere near that much, so the Nexus in my hands is also a longlife
box, just not a box you leave to your grandchildren, like the Rohloff.
But you know, the price difference isn't double, the Rohloff is a
magnitude -- ten times -- more expensive than a Shimano Nexus from the
discounters. That has to be factored in somehow.

Apart from the user interface, where I do think you'll be more
comfortable with the Nexus ;-)

The Nexus has the wonderful user interface even with the rotary
control, and the trigger switch is better still, and the Nexus takes
Shimano's superbly powerful and superbly controllable and very cheap
roller brakes, which the Rohloff can't.

I don't think you can build any DIY system as cheaply as you can buy a
Shimano readymade system, unless you are already into electronics and

...

If you can buy - and use - the Shimano system at all. You'll be doing a
*lot* of searching if you want to buy a brand-new Cyber-Nexus (which
seems to have been out of production for quite a while)... And - as
stated - you won't be able to combine it with non-Shimano components.

I wasn't even able to combine a Shimano chainring with a Shimano
crank-set, at least not without grinding...

That would drive my up the wall already. I honestly don't think you're
going to have much joy mixing and matching SRAM and Nexus components.
You have to choose one or the other. The 3x9 system is very popular in
Germany, I believe, presumably for loaded touring and riding in
mountains where 8 or 9 speeds are not enough.

So I don't suppose, I'll be able to use the Shimano system for my bike
anyway. Still, I do see the benefit of shifting with electrical assist.
But I don't see a solution ready for my use...

Anyway, have fun with it...

Well, I've moved on from Shimano Nexus. I'll be selling my Nexus and
Cyber Nexus bikes as my Rohloff bike totally overlaps their functions
(while I live up this hill), and my Rohloff box is in a superb custom
frame too which is such a pleasure to ride that I'm always raring to
go even in the miserable weather we've had so far this year.

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

On Apr 29, 10:14*am, Bernhard Agthe wrote:
Hi,

Andre Jute wrote:
There's a speed sensor in the dedicated hub dynamo of Shimano's Cyber

Seems sensible.

Nexus gruppo, and an inclination sensor somewhere. The central

Are you sure? I would rather suspect a cadence sensor in the custom
bottom bracket.

No, there's no cadence sensor; nothing at all connected electronically
to the bottom bracket. Shimano tells us there is a magnet in the
gruppo's proprietary hub dynamo which signals speed. Someone else
posited that an accelerometer could be used for measuring tilt in
addition to the speed sensor; I'll see if I can find it when I service
the bike before I sell it on.

Looking at the Cyber-Nexus images, the bottom bracket
really seems special...

Perhaps you're looking at the derailleur autoshif images because there
is nothing special about the bottom bracket for the hub dynamo Cyber
Nexus gruppo.

The recommended bottom bracket, as all Shimano bottom brackets with
suffix K, is special only in missing a spacer provided on other bottom
brackets. This is supposed to save pennies but in fact at retail it
never does. The space from which the spacer is missing is occupied by
the thickness of the chain case.

The rest is just a bit of electronic computation... Any standard
cyclometer has enough calculating power for that...

Ciao...

Gotta go; up early in the morning for surgery.

Ciao.

Andre Jute
You can ride only one bike at a time

"Andre Jute" ha scritto...

Of course it calculates effort, to compare it to the effort level
chosen as a target, but it measures effort indirectly.

In which way?

There's a speed sensor in the dedicated hub dynamo of Shimano's Cyber
Nexus gruppo, and an inclination sensor somewhere. The central
processing unit of the electronic controller knows in which gear the
bike is and the ratio of that gear. Speed, inclination and gear
together give effort, indirectly as I said.
The rider sets his desired optimum effort on a dial, the
electronics compare the current real effort to the desired effort,
and changes accordingly.

From the Shimano document Carl Fogel posted, it is clear that the
gear is selected based solely on the bicycle speed (and on the dial's
setting).

I wouldn't call 'speed' an 'indirect measurement of effort',
but I'm sure that for comfort cycling this system works well.

[...]
Andre Jute

bye
Gennaro

On May 4, 6:21*pm, "Gennaro" wrote:

I'm sure that for comfort cycling this system works well.

I know. I have a bike with Shimano's Cyber Nexus gruppo. It works
brilliantly.

I haven't heard the slightest argument to justify your patronizing
effort to limit the advantage of the simple Cyber Nexus type of speed-
controlled automatic gearchanging to comfort cycles. I haven't heard
the slightest argument even to begin to persuade me that the Cyber
Nexus concept isn't superior over its range to a derailleur system for
any purpose whatsoever. I haven't heard the slightest argument even to
begin to persuade me that a Shimano Cyber Nexus type automatic system
wouldn't be superior on a Rohloff to the obstreperous Rohloff rotary
control, certainly for road use.

In fact, I can't even see that the drastically cut-down Cyber Nexus
which is the Dura-Ace electronically assisted shifting for racers has
any advantage over the full Cyber Nexus -- even for racers -- except
perhaps weight, which I suspect is rather smokey argument. It is pure
and simple macho bull**** to claim, as has been repeatedly claimed
here by the wannabe Lances, that a human can shift faster than
electronics, and the claim that on a road bike a human shifts more
appropriately than electronics is, if true at all, only temporarily
true -- and we all know it, even if the usual luddites are slow to
admit it.

Experience and results are what count, feller, not machismo posturing
about the fastest shift in the West.

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

Gennaro wrote:
I wouldn't call 'speed' an 'indirect measurement of effort',
but I'm sure that for comfort cycling this system works well.

I'm sure this blasphemy won't go unnoticed, but I won't notice
anyway...

Otherwise: agreed, if "comfort cycling" is defined as "always
staying inside a certain cadence range". Not comfortable for me
when riding through town, but of course YMMV.

--
MfG/Best regards
helmut springer panta rhei