Noisy bottle dynamo - is there any maintenance I can do?
Henry Law
about dynamos (which surprised me), so here goes my first post to
rec.bicycles.tech ...
My wife's bike (gash, heavy traditional touring bike about twenty
years old) has a tyre-driven dynamo which consists of an aluminium
bottle-shaped body with, at the top of the "neck", a knurled wheel
which rubs on the tyre; connections to the lights come out of the
bottom of the bottle. By way of maker's marks there is just a "U",
plus stuff about being made in Germany, but my review of newsgroup
postings suggests that it's a "bottle dynamo", possibly made by Union?
There are two problems with it: (1) it makes a noise like an air-raid
siren when in use (only a slight exaggeration); (2) it adds enough
resistance (says my not-unfit wife) to turn the machine into an
exercise bicycle. Power output is fine, though. I have an identical
unit on my bike, which is much quieter and adds only a little
resistance.
I've taken the "bottle" off, undone the only visible nut, securing the
knurled wheel in position, and done the usual sort of cleaning and
greasing, without obvious effect.
Is there any other maintenance I can do on the thing that might cure
the problem?
--
Henry Law <>< he...@thelaws.demon.co.uk
I used to be h...@thelaws.demon.co.uk
Manchester, England but I had to move because of spam
A Muzi
brand name "Margil". It damps vibration and gears the unit down a little
(less likely to blow bulbs at speed).
Ideally, the unit should be set along a radian of the wheel- the axis of
the dynamo should point to the hub. Ensure that it's not hitting any tire
knobs which raise hell with the bearings.
Set it reasonably close to the tire such that there is a firm contact when
the latch is released.
It is also possible the unit's sleeve bushings are shot. If so, at
certain speeds the armature rattles all over the place instead of
spinnning quietly. Does it have more sideplay that your own?
You're right, that's a Union, now called Marwi, unit. Good midrange
dynamo overall.
Henry Law wrote:
--
Yellow Jersey, Ltd
http://www.yellowjersey.org
Open every day since 1 April, 1971
Frank Palermo
kids toy bricks) tyre. I used one on a dynamo for ages.
Cheers,
Frank
Markus Imhof
>
> If at all possible, get a rubber pulley cover also known by the defunct
> brand name "Margil". It damps vibration and gears the unit down a little
> (less likely to blow bulbs at speed).
Just to add my .01 € worth...
>
> Ideally, the unit should be set along a radian of the wheel- the axis of
> the dynamo should point to the hub.
Easiest (IMO) way to verify that is to tie a piece of string to the axle
of the wheel, then pull out the string along the dynamo when it's in the
'on wheel' position and align the dynamo's axle to the string.
...
> It is also possible the unit's sleeve bushings are shot. If so, at
> certain speeds the armature rattles all over the place instead of
> spinnning quietly. Does it have more sideplay that your own?
Or (simply...) that the axle has moved inside the housing
(longitudinal), so that the moving magnet part is rubbing against
something. Again, test it against your dynamo by spinning it by hand.
>
> You're right, that's a Union, now called Marwi, unit. Good midrange
> dynamo overall.
>
Depends - there are several models, and I personally wouldn't bother too
much with any extensive maintenance on the cheaper ones. Depending on
what you're willing to spend (regarding hassle with old one, amount of
night riding, money available), I'd recommend one of the following (in
ascending order):
- Axa HR (Netherlands)
- Nordlicht (Germany)
- B&M 6 (www.bumm.de)
- B&M S6 (www.bumm.de)
- SON (hub generator, www.nabendynamo.de)
Or either http://simon.trinhall.cam.ac.uk/bike/dynotest.html or, if your
German is up to it,
http://experte.kt2.tu-harburg.de/fahrrad.html#beleuchtung
HTH
Bye
Markus
Henry Law
wrote:
>A Muzi wrote:
... and other people wrote too.
Thank you very much for the hints and tips. What a pleasant group
(and interesting too); I'll keep watching!
Frank Krygowski
>
> My wife's bike (gash, heavy traditional touring bike about twenty
>
> There are two problems with it: (1) it makes a noise like an air-raid
> siren when in use (only a slight exaggeration); (2) it adds enough
> resistance (says my not-unfit wife) to turn the machine into an
> exercise bicycle. Power output is fine, though. I have an identical
> unit on my bike, which is much quieter and adds only a little
> resistance.
>
> I've taken the "bottle" off, undone the only visible nut, securing the
> knurled wheel in position, and done the usual sort of cleaning and
> greasing, without obvious effect.
>
> Is there any other maintenance I can do on the thing that might cure
> the problem?
What was "the usual sort" of cleaning and greasing?
That generator has plain bearings (that is, not ball bearings)
supporting the shaft. I haven't used one of that brand long enough to
wear it out, but I've heard that the top bearing does wear first. There
aren't any provisions for re-lubricating it. Perhaps it's porous
bronze, forming its own oil reservoir, but apparently that's not
sufficient for infinite life.
However, in _most_ cases where husband and wife share identical
equipment, the wife's is not likely to wear out sooner. Men tend to put
on more miles, especially in adverse conditions (like darkness). So I'm
wondering if it's simply a dry bearing.
In addition to double-checking the mounting alignment, as others
suggested, I'd be sure to lubricate that top bearing. It does require
removing the drive pulley to get access. (I've heard of folks drilling
an oil hole through that pulley, and re-lubing regularly using a needle
lubricator.)
I wonder if a shot of penetrating oil might be good, before a follow-up
with light machine oil.
Please be sure to let us know what works!
--
Frank Krygowski frkr...@cc.ysu.edu
Carlos Klimann
Carlos
stick...@gmail.com
Will have to wait and see whether it slips in wet conditions...
AMuzi
> A dynamo cap did the trick for me. Just a little rubber cap that fits over the metal cog - went from the whining unbearable "air raid siren" to much more acceptably quiet with this super cheap attachment.
>
> Will have to wait and see whether it slips in wet conditions...
>
with the hole on top better but still all too fast.
Cutting a groove on the pulley for a Viton o-ring is another
improvement beyond a cap. (I just happen to have a lathe and
an assortment of o-rings at hand- this might be harder for
others.)
--
Andrew Muzi
<www.yellowjersey.org/>
cycl...@yahoo.com
Frank Krygowski
> On 7/24/2020 5:26 AM, stick...@gmail.com wrote:
>> A dynamo cap did the trick for me. Just a little rubber cap that fits
>> over the metal cog - went from the whining unbearable "air raid siren"
>> to much more acceptably quiet with this super cheap attachment.
>>
>> Will have to wait and see whether it slips in wet conditions...
>>
>
>
> I found them to wear quickly, the Velox faster, the Sanyo with the hole
> on top better but still all too fast.
>
> Cutting a groove on the pulley for a Viton o-ring is another improvement
> beyond a cap. (I just happen to have a lathe and an assortment of
> o-rings at hand- this might be harder for others.)
of the rim instead of on the tire sidewall. It's very quiet.
--
- Frank Krygowski
Frank Krygowski
dynamos) but if properly installed, they are fine. This well-known
article http://www.myra-simon.com/bike/dynotest.html
says, in part, "All of the generators were easier to turn than riding up
a 1 in 300 slope. Another way of putting that is a rise of 18 feet per
mile; and there's quite a cluster of sidewall and hub-driven models
around the 1/500 line, or 10 ft per mile. If that's a hill I'm a Dutchman!"
I've got bottle generators on a couple bikes, ones that I normally don't
ride at night. The drag is barely noticeable when they're on. And they
make up for that by having absolutely zero drag when off, unlike hub dynos.
> Hub generators are where it's at. Look at this which is dirt cheap and you would have to have it built into a wheel which would still make it cheap. https://www.ebay.com/itm/Nukeproof-Generator-Front-Hub/324238672050?hash=item4b7e2180b2:g:KBsAAOSwunhfGeZO
not a dynamo. It doesn't generate any electricity.
--
- Frank Krygowski
AK
Based on my experience,
The dynamo will wear your tires down very rapidly.
Andy
AMuzi
Tosspot
> A dynamo cap did the trick for me. Just a little rubber cap that fits over the metal cog - went from the whining unbearable "air raid siren" to much more acceptably quiet with this super cheap attachment.
>
> Will have to wait and see whether it slips in wet conditions...
>
surface, this also slips ime. The best bottle dynamo I sed was a
Nordlicht, but given the price I'd go hub dynamo these days.
retrog...@gmail.com
You'll soon be disabused of that misconception, Henry!
(Just kidding. Of course.)
Jeff Liebermann
<frkr...@sbcglobal.net> wrote:
>> Hub generators are where it's at. Look at this which is dirt cheap
>> and you would have to have it built into a wheel which would still
>> make it cheap.
>> https://www.ebay.com/itm/Nukeproof-Generator-Front-Hub/324238672050
>not a dynamo. It doesn't generate any electricity.
apparently contrived by the manufacturer:
<http://nukeproof.com/products/hubs/>
The eBay $10 price, plus $8.25 shipping, is the starting price for an
auction and not the "buy it now" price. Retail price is about $42:
<http://www.groupbikes.com/products/Nukeproof-Generator-Front-Hub-%252d-15mm%252dQR-2016.html>
--
Jeff Liebermann je...@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
cycl...@yahoo.com
AMuzi
[raises hand] Marketing!
c.f. Communist front named 'BLM', another successful example
of 3 card monte.
cycl...@yahoo.com
Jeff Liebermann
>You ask why?
My guess(tm) is someone at NukeProof coined the term due to a
defective understanding of the English language. They then discovered
that it sold quite well, which seemed like a good reason to not change
the name. I'm sure the FTC will be happy to write NukeProof a polite
letter indicating that this might be false and deceptive advertising.
However, since few buyers bother to file a complaint, the likelihood
of the FTC demonstrating a profit enforcing the complaint due to
collection costs from China, and nobody at NukeProof can read English,
I suspect the legal approach will go nowhere, or already has gone
nowhere.
<https://www.ftc.gov/news-events/media-resources/truth-advertising>
<https://www.ftc.gov/faq/consumer-protection/submit-consumer-complaint-ftc>
<https://www.ftccomplaintassistant.gov>
>[raises hand] Marketing!
The purpose of marketing is to confuse the potential customers. Once
confused, they will usually ask the experts, visit an LBS, ask on
R.B.T., or whine of Facebook to find a solution to their confusion.
That's when marketing arrives and proposes a product that is intended
to solve the customers problem and end the confusion. Therefore, to
increase sales, it is a simple matter to increase the confusion. I
call to your attention the product naming and numbering conventions of
Apple products as a good example.
<https://support.apple.com/en-us/HT201300>
>c.f. Communist front named 'BLM', another successful example
>of 3 card monte.
will we do when we run out of TLA's?
<https://acronyms.thefreedictionary.com/BLM>
Obligatory bicycle related drivel:
These days, I prefer mega-lumen bicycle lighting. However, when I was
young and clueless, I used a bottle dynamo. To reduce the dynamo
noise, I wrapped a few thick rubber bands around the drive wheel. The
rubber bands didn't last very long, but I usually had a pocket full of
spares normally used for the rubber band gun, stem mounted sling shot,
or the rear rack mounted catapult.
<https://www.google.com/search?q=rubber+band+clothespin+gun&tbm=isch>
One of these would have been nice:
<https://www.youtube.com/watch?v=tEVBwaFFyP0>
cycl...@yahoo.com
> On Sat, 25 Jul 2020 15:52:11 -0500, AMuzi <a...@yellowjersey.org> wrote:
>
> >You ask why?
>
> My guess(tm) is someone at NukeProof coined the term due to a
> defective understanding of the English language. They then discovered
> that it sold quite well, which seemed like a good reason to not change
> the name. I'm sure the FTC will be happy to write NukeProof a polite
> letter indicating that this might be false and deceptive advertising.
> However, since few buyers bother to file a complaint, the likelihood
> of the FTC demonstrating a profit enforcing the complaint due to
> collection costs from China, and nobody at NukeProof can read English,
> I suspect the legal approach will go nowhere, or already has gone
> nowhere.
> <https://www.ftc.gov/news-events/media-resources/truth-advertising>
> <https://www.ftc.gov/faq/consumer-protection/submit-consumer-complaint-ftc>
Jeff Liebermann
"How to write an effective complaint letter"
<https://www.consumer.ftc.gov/blog/2015/09/how-write-effective-complaint-letter>
There are even sample complaint letters available that can be
plagerized:
<https://www.usa.gov/complaint-letter>
As a victim of the American educational system, I highly recommend you
try complaining about some of the things you've posted in a bicycle
specific newsgroup. It might be a useful skill for after you're
released from the re-education camp for treason, sedition,
crime-think, or failing to agree with whomever is in power.
However, the problem is not just a letter of complaint. I suspect
that the real problem is that there are too few people who are able to
write anything worth reading. I try to answer questions in a few of
the technical newsgroups. Many of the questions posted are impossible
to answer with the information given and are vague, ambiguous, and
incoherent. Many are one line questions with no details. Some are
devoid of any useful numbers. I suspect a few were intentionally
edited to remove any and all specific and useful information. It's
likely that anyone who cannot properly frame a technical question,
might also be unable to compose a letter of complaint.
Frank Krygowski
True story: I recently had a minor surgical procedure. Things did not go
as planned. Despite being scheduled for 9 AM, my work was delayed at
least an hour and a half. And there were other problems causing more
delay, such as a nurse making a mistake and requiring critical equipment
to be re-sterilized.
I did write a letter of complaint. The response? Not only a personal
phone call with sincere apologies from the hospital president, but I
spent about 45 minutes on a conference call with that president and two
department supervisors to understand how things went wrong.
When asked, I gave them permission to use my letter in future training
sessions.
--
- Frank Krygowski