Proper impeller play on a Union (Con-tec)dynamo?

On Sunday, November 15, 2020 at 8:38:15 PM UTC-6, Frank Krygowski wrote:
On 11/15/2020 3:30 PM, landotter wrote:
On Sunday, November 15, 2020 at 2:03:56 PM UTC-6, AMuzi wrote:

by the way, welcome back Mr Landotter!
--

Thanks!

I'm still grumpy. But nothing like you old farts.

https://photos.app.goo.gl/uQs1sYMtjG8vJtWa8
The "ENTERING GOLF COURSE QUIET" sign in your photo reminds me of a very
early cycling incident.

We were young marrieds in the 1970s, just getting into bicycling and
wondering how on earth someone could ride 50 miles, let alone 100. Then
someone in the U.S. government started a program called the Presidential
Sports Award, intending to get people active. You could choose from
dozens of activities (swimming, table tennis, backpacking...) and get a
patch and pin if you did it consistently enough and kept records to
document your participation for several months.

IIRC the Bicycling badge required something like 600 miles in four
months, an average of just five miles per day. But you couldn't count
any more than 12 miles on any one day. (You could ride them; they just
didn't count toward the award.) The idea was consistency, not weekend
warrior behavior.

We sent away, got our logbooks and began riding very consistently,
ticking off the days and miles. Finally, I watched my mechanical
cyclometer as we rode a pretty road alongside a local golf course. We
were quite excited as I said "Two tenths to go... one tenth to go.. WE
DID IT!" And we both shouted "HOORAY!"

... just as a nearby golfer had finished his backswing. His ball went
off in some bad direction and he gave us a look that could kill.


"And that golfers name was Donald Trump, you socialist!"

-Andre Jute

On 11/15/2020 9:54 PM, landotter wrote:
On Sunday, November 15, 2020 at 8:38:15 PM UTC-6, Frank Krygowski wrote:
On 11/15/2020 3:30 PM, landotter wrote:
On Sunday, November 15, 2020 at 2:03:56 PM UTC-6, AMuzi wrote:

by the way, welcome back Mr Landotter!
--

Thanks!

I'm still grumpy. But nothing like you old farts.

https://photos.app.goo.gl/uQs1sYMtjG8vJtWa8
The "ENTERING GOLF COURSE QUIET" sign in your photo reminds me of a very
early cycling incident.

We were young marrieds in the 1970s, just getting into bicycling and
wondering how on earth someone could ride 50 miles, let alone 100. Then
someone in the U.S. government started a program called the Presidential
Sports Award, intending to get people active. You could choose from
dozens of activities (swimming, table tennis, backpacking...) and get a
patch and pin if you did it consistently enough and kept records to
document your participation for several months.

IIRC the Bicycling badge required something like 600 miles in four
months, an average of just five miles per day. But you couldn't count
any more than 12 miles on any one day. (You could ride them; they just
didn't count toward the award.) The idea was consistency, not weekend
warrior behavior.

We sent away, got our logbooks and began riding very consistently,
ticking off the days and miles. Finally, I watched my mechanical
cyclometer as we rode a pretty road alongside a local golf course. We
were quite excited as I said "Two tenths to go... one tenth to go.. WE
DID IT!" And we both shouted "HOORAY!"

... just as a nearby golfer had finished his backswing. His ball went
off in some bad direction and he gave us a look that could kill.


"And that golfers name was Donald Trump, you socialist!"

-Andre Jute

:-)


--
- Frank Krygowski

On Saturday, November 14, 2020 at 3:25:35 PM UTC-6, Tosspot wrote:
On 14/11/2020 21:52, landotter wrote:

snip
Hub dynamos are fine for low mileage bikes at the 50 buck price
point. If you're doing brevets, you'll want something German of
course that's gonna be a few hundred bux with a couple Schmitty
lights as well.
That's weird, I have one of these;

https://www.amazon.de/SHIMANO-Fahrra.../dp/B07D33ZW4N
(26 euros delivered free)

Still going strong approaching 40,000km. In fact it and it's rim are
the only original parts of that bike i think.

snip
Stroke of luck. All Nexus stuff is really vulnerable to rain. Terrible seals. I generally adore Shimano hubs and would gladly circle the globe on the cheapest Deores. The gearhubs are easily rebuilt to be waterproof with non OEM lubricants, the dynohub I have yet to rebuild as they aren't common here.

I'm in the mid southern US and not back in Sweden so needs differ. Any bike I bought there would come with the Shimano. Here it's a pointless draggy hub for 8 months out of the year. Latitudes matter. When we get rain it's monsoon like and it eats vulnerable bearings for breakfast.

So the idiosyncratic use of a trad bottle and LED is perfect. Incredibly uncommon but practical. The draw from LED is so little that the bottle drags very little.

Of course at a higher price point, the German models are handsome. The Shimano on a traditional roadster is sad aesthetically. Most modern Shimano design is the pits.

On Sunday, November 15, 2020 at 8:50:07 AM UTC-8, landotter wrote:
On Sunday, November 15, 2020 at 10:14:07 AM UTC-6, AMuzi wrote:
On 11/14/2020 2:52 PM, landotter wrote:
On Saturday, November 14, 2020 at 2:24:27 PM UTC-6, wrote:
On Saturday, November 14, 2020 at 12:12:02 PM UTC-8, Tosspot wrote:
On 14/11/2020 19:40, AMuzi wrote:
On 11/14/2020 12:19 PM, landotter wrote:
On Saturday, November 14, 2020 at 12:06:42 PM UTC-6, Frank Krygowski
wrote:
On 11/14/2020 11:49 AM, landotter wrote:
I put a rear triangle dynamo on my retro roadster with a 50 lux
Cordo LED lamp and it's the tits. Works great, weighs eh nuttin, and
you can switch it 100% off. Cost about 12 bucks for the dynamo and
25 for the lamp. Oh boy. Big spender, but it kept the front wheel
looking bulgy hubbed and new fanglish. 50 lux is fifty lux. works
fine, but I wanna dial it in to get that edge riding across town to
pick up fava beans, ya know?

These days if you want a new silver olde timey looking jobber it's
an AXA 8201 or the Con-tec DL-150. Both are a tenner and a bit. The
Con-tec appears to be a rebranded Union-Marwi and the "U" on the
spring cover is kind of a giveaway AND it comes with a little
impeller cover, so it won out.

I dripped a single drop of oil down the impeller shaft and then put
a glob of red Sta-Plex grease on top of the bushing before putting
on the roller and lock nut. Friction really ain't anything now.
Spins like the dickens. Doesn't get hot. It's happy on a real dynamo
track on a Schwalbe tire without too much pressure.

But it still rattles a bit. I reckon it's the simple bearing
whacking against the bushing. Would adjusting play even matter? I'v
got it at a generous couple millimeters.

My solution has been to listen to quiz shows at a medium volume and
enjoying that the rattle has probably extended the life of my Crane
bell as pedestrians seem very irritated by it.
A couple millimeters end play sounds really excessive. My similar
dynamos are adjusted for near zero end play.


--
- Frank Krygowski


I'll dial it in tightish and give it a whirl tonight. Seeing as there
are no ball bearings and the impeller follows tire imperfections, I
figured it might be one of those situations where a little slop was good.

My weird theory is that it's not terribly important on a consumable
dynamo but what's happening is that the LED draw is so little that the
magnety spinny action isn't as strong to keep it centered in the bushing.

It's a silly chasing rainbows thing as my bicycle is otherwise a
silent appliance. Hahaha!


Most have a simple bronze journal, not a ball bearing. They do run much
better with firm pressure than with occasional slip.
I may be wrong, but istr the nordlicht dynamos were ball bearing. I
never found a bottle dynamo that didn't slip under some ****ty weather
condition although the Nordlicht was quite good for its genre.

I used a spoke dynamo for a while, they don't slip :-)
I agree with you. I never saw a bottle dynamo that also didn't wear the tires out rapidly. Installing a hub dynamo was like a new world. I can't remember clearly but I think that I had a multispeed hub with a dynamo built into it as well.

I've never seen a properly installed bottle wear out a tire and I grew up with them so saw a ****ton in Sweden. Of course the incandescent lamps were pretty terrible and the halogens a mild improvement. LED changes everything.

Wheel dynamos will always drag, look fugly as hell, cost a heck of a lot more, and never really are weather resistant. Yeah, they're standard on even 6-700 bikes now in Sweden along with the ubiquitous Shimano Nexus 3 which is also a disaster when it comes to weather. I run a Nexus too, but redid it with all fresh stainless balls and thick Sta-Plex grease with a little oil on the pawl pivots. A far better solution than Shimano hub grease, which is the same drippy white lithium used in cotton pickers. You can buy it by the gallon at the Tractor supply for cheap.

Hub dynamos are fine for low mileage bikes at the 50 buck price point.. If you're doing brevets, you'll want something German of course that's gonna be a few hundred bux with a couple Schmitty lights as well.

A bottle dynamo running a cheap and cheerful 35-70 lux LED light runs with very little drag and really has no drawbacks if one has the slightest mechanical ability. It's the perfect fit and forget part. You can always have a strap on battery light for those times you want to do more silent urban riding, but the bottle will always be there.

I don't like new fangled that just introduces new problems that are smaller and more of a pain in the ass. It's like cartridge headsets for most non-mtb riding. They're usually fine, but if there's an issue, it's always dumb. Loose balls and marine grease are last century and can be fixed with a rock.


+1 on that dynamo & tire wear. I've only seen that in rare
cases of gross misalignment.
--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971
I got the play out and the bottle a little more parallel. It was a sloppy impeller adjustment from the factory and the bracket which was designed for a 1922 roadster kicked out the bottom of the bottle a little as the seatstays are a little different on a modern bike. It worked great before, but now it's sounding like a good 'ol Union should. It needs only walking speed to get to full blast. It would benefit from a roller cover the diameter of a quarter or a krona. Haha.

Here it is mounted.

https://photos.app.goo.gl/m31fcoQHtUnZSM2M8
I can only assume you don't use that bike in wet and sloppy conditions because that's more or less the way I had them and they would slip on the sidewall and wear them out. Even to the point of getting sidewall flats.

On Monday, November 16, 2020 at 6:39:57 AM UTC-8, landotter wrote:
On Saturday, November 14, 2020 at 3:25:35 PM UTC-6, Tosspot wrote:
On 14/11/2020 21:52, landotter wrote:

snip
Hub dynamos are fine for low mileage bikes at the 50 buck price
point. If you're doing brevets, you'll want something German of
course that's gonna be a few hundred bux with a couple Schmitty
lights as well.
That's weird, I have one of these;

https://www.amazon.de/SHIMANO-Fahrra.../dp/B07D33ZW4N
(26 euros delivered free)

Still going strong approaching 40,000km. In fact it and it's rim are
the only original parts of that bike i think.

snip
Stroke of luck. All Nexus stuff is really vulnerable to rain. Terrible seals. I generally adore Shimano hubs and would gladly circle the globe on the cheapest Deores. The gearhubs are easily rebuilt to be waterproof with non OEM lubricants, the dynohub I have yet to rebuild as they aren't common here.

I'm in the mid southern US and not back in Sweden so needs differ. Any bike I bought there would come with the Shimano. Here it's a pointless draggy hub for 8 months out of the year. Latitudes matter. When we get rain it's monsoon like and it eats vulnerable bearings for breakfast.

So the idiosyncratic use of a trad bottle and LED is perfect. Incredibly uncommon but practical. The draw from LED is so little that the bottle drags very little.

Of course at a higher price point, the German models are handsome. The Shimano on a traditional roadster is sad aesthetically. Most modern Shimano design is the pits.
Unless you're drawing current from generator hubs they shouldn't be offering any drag at all. They have no friction surfaces and like all generators only offer resistance when they are in use.

On 11/16/2020 11:36 AM, Tom Kunich wrote:

Unless you're drawing current from generator hubs they shouldn't be offering any drag at all. They have no friction surfaces and like all generators only offer resistance when they are in use.

"Shouldn't be offering any drag at all" is true only in the aspirational
sense. They all have some drag (usually minor) when off, due to eddy
current losses if nothing else. This is documented through many tests by
many different investigators. There are have even been a few models that
have less drag on than off.

Really, Tom, you should do a _little_ study before posting.

--
- Frank Krygowski

On Monday, November 16, 2020 at 11:31:59 AM UTC-6, Frank Krygowski wrote:
On 11/16/2020 11:36 AM, Tom Kunich wrote:

Unless you're drawing current from generator hubs they shouldn't be offering any drag at all. They have no friction surfaces and like all generators only offer resistance when they are in use.
"Shouldn't be offering any drag at all" is true only in the aspirational
sense. They all have some drag (usually minor) when off, due to eddy
current losses if nothing else. This is documented through many tests by
many different investigators. There are have even been a few models that
have less drag on than off.

Really, Tom, you should do a _little_ study before posting.


Oh y'all. But yeah, I don't know the science of it, but you can feel it for sure on the cheapies. I'm not overly concerned with it and like I said, if I got one on a roadster bike back home OEM, I'd repack the bearings and ride it till it dies. But I wouldn't build a wheel with one. It looks like a couple tuna cans with flanges.

On Monday, November 16, 2020 at 9:31:59 AM UTC-8, Frank Krygowski wrote:
On 11/16/2020 11:36 AM, Tom Kunich wrote:

Unless you're drawing current from generator hubs they shouldn't be offering any drag at all. They have no friction surfaces and like all generators only offer resistance when they are in use.
"Shouldn't be offering any drag at all" is true only in the aspirational
sense. They all have some drag (usually minor) when off, due to eddy
current losses if nothing else. This is documented through many tests by
many different investigators. There are have even been a few models that
have less drag on than off.

Really, Tom, you should do a _little_ study before posting.

Gads, just go spin my SP PD8 in the truing stand.

-- Jay Beattie

On Monday, November 16, 2020 at 9:31:59 AM UTC-8, Frank Krygowski wrote:
On 11/16/2020 11:36 AM, Tom Kunich wrote:

Unless you're drawing current from generator hubs they shouldn't be offering any drag at all. They have no friction surfaces and like all generators only offer resistance when they are in use.
"Shouldn't be offering any drag at all" is true only in the aspirational
sense. They all have some drag (usually minor) when off, due to eddy
current losses if nothing else. This is documented through many tests by
many different investigators. There are have even been a few models that
have less drag on than off.

Really, Tom, you should do a _little_ study before posting.

--
- Frank Krygowski

Really Frank, you should know that in a properly designed generator there would be no eddy currents generated unless and until there was an actual current flow pathway. Not having use the Shimano generator in a long time I was unaware that they were improperly designed.

Op maandag 16 november 2020 om 18:31:59 UTC+1 schreef Frank Krygowski:
On 11/16/2020 11:36 AM, Tom Kunich wrote:

Unless you're drawing current from generator hubs they shouldn't be offering any drag at all. They have no friction surfaces and like all generators only offer resistance when they are in use.
"Shouldn't be offering any drag at all" is true only in the aspirational
sense. They all have some drag (usually minor) when off, due to eddy
current losses if nothing else. This is documented through many tests by
many different investigators. There are have even been a few models that
have less drag on than off.

Really, Tom, you should do a _little_ study before posting.

--
- Frank Krygowski


Mine is about 1 Watt at 30 km/hr. That is the good 'German' one, a cheap Shimano one is about 3.5 Watt.

Lou