Any comments on the Supernova Infinity dynamo hub

I ran across this particular dyno hub
http://www.supernova-lights.com/en/products/infinity_8.html while
scouring the web for a dynamo hub (hey, Google search sometimes
works...). Does anybody have any experience with this manufacturer's
product?

On 28/09/2011 14:45, Ralph Barone wrote:
I ran across this particular dyno hub
http://www.supernova-lights.com/en/products/infinity_8.html while
scouring the web for a dynamo hub (hey, Google search sometimes
works...). Does anybody have any experience with this manufacturer's
product?

No, but it does look a bit like a solution in search of a problem. Even
the worst of the old Shimano dynohubs gives barely any drag. It also
means you can't simply switch on while riding (tunnels, etc) or have
fit-and-forget autosensing lights. And it costs more than a SON.

One point of interest though is the development of LED dynamo lights has
allowed this hub to do its other thing - plug it into a halogen set, and
bulbs would be blowing. That curve of voltage againsts speed doesn't
show it's superior, it shows it's worse-regulated. But for a modern LED
lamp with clever electronics, that doesn't actually matter.

Clive George wrote:
On 28/09/2011 14:45, Ralph Barone wrote:
I ran across this particular dyno hub
http://www.supernova-lights.com/en/products/infinity_8.html while
scouring the web for a dynamo hub (hey, Google search sometimes
works...). Does anybody have any experience with this manufacturer's
product?

No, but it does look a bit like a solution in search of a problem. Even
the worst of the old Shimano dynohubs gives barely any drag. It also
means you can't simply switch on while riding (tunnels, etc) or have
fit-and-forget autosensing lights. And it costs more than a SON.

One point of interest though is the development of LED dynamo lights has
allowed this hub to do its other thing - plug it into a halogen set, and
bulbs would be blowing. That curve of voltage againsts speed doesn't
show it's superior, it shows it's worse-regulated. But for a modern LED
lamp with clever electronics, that doesn't actually matter.

Do you have any details on the "clever electronics" in modern LED
generator lamps?

I ask because one can get by with very little in the way of electronics.
Bike dynamos (or generators) are, to a good approximation, constant
current devices, in the same way that batteries are, to a good
approximation, constant voltage devices. LEDs need regulated current,
which is exactly what they naturally get from a dynamo. Rectification
and/or protection from excessive back voltage doesn't take much
cleverness, and a standlight, for those who want it, isn't much more
complicated.

So what's in a dynamo LED headlight? Is it more than a diode bridge and
a big capacitor?

--
- Frank Krygowski

Clive George wrote:
:On 28/09/2011 14:45, Ralph Barone wrote:
: I ran across this particular dyno hub
: http://www.supernova-lights.com/en/products/infinity_8.html while
: scouring the web for a dynamo hub (hey, Google search sometimes
: works...). Does anybody have any experience with this manufacturer's
: product?

:No, but it does look a bit like a solution in search of a problem. Even
:the worst of the old Shimano dynohubs gives barely any drag. It also
:means you can't simply switch on while riding (tunnels, etc) or have
:fit-and-forget autosensing lights. And it costs more than a SON.

They're made by a tiawanese company, Shutter precision. Essentially
the same dyanmo is available from other people. (for less money). I
believe the design doesn't actually turn the dynamo off entirely, but
moves the outer part farther away from the axle, reducing its output.

I can't find their patent for it, which I've been told they've got. I
do find their patent on the super small one, which uses powerful
magnets.


--
sig 7

On Sep 28, 11:21*am, David Scheidt wrote:
Clive George wrote:

:On 28/09/2011 14:45, Ralph Barone wrote:
: I ran across this particular dyno hub
: http://www.supernova-lights.com/en/products/infinity_8.html *while
: scouring the web for a dynamo hub (hey, Google search sometimes
: works...). *Does anybody have any experience with this manufacturer's
: product?

:No, but it does look a bit like a solution in search of a problem. Even
:the worst of the old Shimano dynohubs gives barely any drag. It also
:means you can't simply switch on while riding (tunnels, etc) or have
:fit-and-forget autosensing lights. And it costs more than a SON.

They're made by a tiawanese company, Shutter precision. *Essentially
the same dyanmo is available from other people. *(for less money). *I
believe the design doesn't actually turn the dynamo off entirely, but
moves the outer part farther away from the axle, reducing its output.

I can't find their patent for it, which I've been told they've got. *I
do find their patent on the super small one, which uses powerful
magnets. *

I know it is sold through Velo Orange -- for less than a SON, but I
don't know where else it is sold. -- Jay Beattie.

On 9/28/2011 6:45 AM, Ralph Barone wrote:
I ran across this particular dyno hub
http://www.supernova-lights.com/en/products/infinity_8.html while
scouring the web for a dynamo hub (hey, Google search sometimes
works...). Does anybody have any experience with this manufacturer's
product?

I saw it (or someone else's switchable hub) at Interbike on one of the
Tern models, and got a photo of it:
http://nordicgroup.us/interbike2011/img_3150.jpg.

I think the hub in the Tern model is this one:
http://www.sp-dynamo.com/spproductswitchdisc.html. Given Tern's desire
to move upscale in folders, and knowing Josh Hon, I'd be surprised if he
used any really crappy components on his new line. The specs for the
Tern model with the Shutter Precision dynamo hub are at
http://www.ternbicycles.com/bikes/eclipse-s11i?quicktabs_bike_tabs=2#quicktabs-bike_tabs.

Very good idea since the drag on those dynamo hubs when engaged, even
when the lights are off and the hub is not generating any power, is
significant. Fortunately these switchable hubs are not very expensive
either. So rather than spend the big bucks on a Son, you can achieve
even less drag for a lot less money.

On 29/09/2011 10:07, SMS wrote:

Very good idea since the drag on those dynamo hubs when engaged, even
when the lights are off and the hub is not generating any power, is
significant.

That's just utter nonsense. The drag is insignificant, even when generating.

On 29 sep, 16:23, Clive George wrote:
On 29/09/2011 10:07, SMS wrote:

Very good idea since the drag on those dynamo hubs when engaged, even
when the lights are off and the hub is not generating any power, is
significant.

That's just utter nonsense. The drag is insignificant, even when generating.

Would I have a dynahub light system if there were significant drag
when generating?
Would I leave my front wheel with dynahub on my bike during summer
season when there was significant drag when not generating?

Hell no. I do have dynahub light systems and leave my front wheel on
my bike in summer season. So it is utter nonsense and the supernova
hub solves a non existing problem introducing more complexity and
inconvenience.

Lou

SMS wrote:

:Very good idea since the drag on those dynamo hubs when engaged, even
:when the lights are off and the hub is not generating any power, is
:significant. Fortunately these switchable hubs are not very expensive

No, it's not. It is if you're in danger of losing the race by half a
second, but not otherwise.

There's lots of *perceived* drag, but most of that is given back. The
actual drag is low.


--
This is a randomly numbered sig.

On 9/29/2011 7:42 AM, Lou Holtman wrote:
On 29 sep, 16:23, Clive wrote:
On 29/09/2011 10:07, SMS wrote:

Very good idea since the drag on those dynamo hubs when engaged, even
when the lights are off and the hub is not generating any power, is
significant.

That's just utter nonsense. The drag is insignificant, even when generating.

Would I have a dynahub light system if there were significant drag
when generating?

Yes, because the alternative, up until now, has been unacceptable.

Would I leave my front wheel with dynahub on my bike during summer
season when there was significant drag when not generating?

Yes.

Hell no. I do have dynahub light systems and leave my front wheel on
my bike in summer season. So it is utter nonsense and the supernova
hub solves a non existing problem introducing more complexity and
inconvenience.

You don't realize just how much the extra drag actually is. What you
need to do is to compare a dynamo and a non-dynamo wheel, off the bike.

Think about it this way. A human can put out about 1/10 HP continuously
(around 75W). A dynamo is rated at 3W and actually can put out about 6W.

If you're using 3W lights, you're expending about 6W of energy into
running the lights. With the lights off, the energy expended goes down,
the SON required around 5.4W of input with lights off, and around 5.6W
of input power with lights on (for 3W lights). The Shimano Alfine was
slightly worse. See http://www.ecovelo.info/2009/11/05/new-dyno-hub-test/.

So the question is whether or not "saving" 5W of power in the daytime is
worth the extra complexity of a hub dynamo that can disengage the dynamo
when not in use.

My personal feeling is that since I have my lights on in the daytime
anyway (strobe in front, flasher in back) that there's little benefit.
But those doing randonneuring may appreciate the savings in power.