Bicycle Dynamo (sorry a little OT)

[Crash Bang Wall]

I'm looking for a source of bike dynamos, (I require about ten initially) however, I want the old
fashioned type that reside in the hub of a bikes front wheel.

Are these still available or have they been replaced by the type that run on the back wheel?

An idea of cost would be nice too!

Also can anyone advise me as to the output of these dynamo's and if they are more or less efficient
than the type that run on the back wheel?

Cheers all tox

 

[Harry Bloomfiel]

On 16/12/2003 "Crash Bang Wallop" opined:-
> Are these still available or have they been replaced by the type that run on the back wheel?
>
> An idea of cost would be nice too!
>
> Also can anyone advise me as to the output of these dynamo's and if they are more or less
> efficient than the type that run on the back wheel?

Sturmy-Archer was the company which made the hub mounted type. The output (at a guess) was about
2watts peak. It really depends how you mean by efficient....

The hub type were more efficient and more reliable when generating, but they still offered a tiny
amount of resistance when not generating. The friction wheel type tended to slip a little, the head
and bearings wear out quickly cause more drag than the hub type when in use. When not in use they
caused no drag.

--
Regards, Harry (M1BYT)...

Remove the 'NOSPAM' in my email address to reply.

Free Amateur Radio Courses:- http://www.ukradioamateur.org

 

[Colin Blackburn]

On Tue, 16 Dec 2003 09:34:11 -0000, Crash Bang Wallop
<[email protected]> wrote:

>
> I'm looking for a source of bike dynamos, (I require about ten initially) however, I want the old
> fashioned type that reside in the hub of a bikes front wheel.
>
> Are these still available or have they been replaced by the type that run on the back wheel?

These are very much available and far from old fashioned these days.

> An idea of cost would be nice too!

There are two readily available brands in the UK (I think I noticed a third in some catalogue last
week and some places sell old SA stuff). The Shimano Nexus hub dynamo is around the £50 mark. The
Schmidt Nabendynamo (SON) is around £110.

http://www.sjscycles.com/store/vIndex.htm?cat366.htm

stock both makes.

> Also can anyone advise me as to the output of these dynamo's and if they are more or less
> efficient than the type that run on the back wheel?

Both of the above are much more efficient than bottle dynamos. The latter of the two is more
efficient than the first though its big advantage over the former is that it presents much less drag
when it isn't turned on---this may not be a significant advantage for you since I would guess you
don't want them for cycling.

They are designed to deliver 3W at 6V when in a standard bike wheel. There are versions for smaller
wheels (which rotate faster at a given road speed.) You may need to do a little research to work out
whether they suit your needs.

Colin
--

 

[Peter Clinch]

Crash Bang Wallop wrote:
> I'm looking for a source of bike dynamos, (I require about ten initiall=
y)
> however, I want the old fashioned type that reside in the hub of a bike=
s
> front wheel.
>=20
> Are these still available or have they been replaced by the type that r=
un on
> the back wheel?

Dynohubs are still available, and the only reason that "bottle dynamos"=20 own more of the market is
they're a lot cheaper and don't need wheel=20 building to mount. The Top Banana dynohub is the
Schmidt SON, very good, but rather=20 expensive (=A3110). Shimano do one called the Nexus, which is
almost as =

good but costs a lot less (ca. =A350 IIRC).

> Also can anyone advise me as to the output of these dynamo's and if the=
y are
> more or less efficient than the type that run on the back wheel?

There's some spiel on the SON at=20 http://www.kinetics.org.uk/html/son_hub_dynamo.shtml and Ben,
the chap=20 that runs the Kinetics shop, Knows His Stuff and sells B&M bottle=20 dynamos too. He'd
probably be happy to have a blether about the=20 technical details (which he will know far better
than me!).

Pete. --=20 Peter Clinch University of Dundee Tel 44 1382 660111 ext. 33637 Medical Physics,
Ninewells Hospital Fax 44 1382 640177 Dundee DD1 9SY Scotland UK net [email protected]
http://www.dundee.ac.uk/~pjclinch/

 

[Tony Raven]

Crash Bang Wallop wrote:
> I'm looking for a source of bike dynamos, (I require about ten initially) however, I want the old
> fashioned type that reside in the hub of a bikes front wheel.
>
> Are these still available or have they been replaced by the type that run on the back wheel?
>
> An idea of cost would be nice too!
>
> Also can anyone advise me as to the output of these dynamo's and if they are more or less
> efficient than the type that run on the back wheel?
>

Plenty still available. Shimano and Schmidt are popular. You can get the former for about £25
upwards. The latter is more expensive. All you need to know about output is at http://www.myra-
simon.com/bike/dynotest.html

Tony

 

[Michael MacClan]

"Crash Bang Wallop" <[email protected]> wrote in message
news:[email protected]...
>
> I'm looking for a source of bike dynamos, (I require about ten initially) however, I want the old
> fashioned type that reside in the hub of a bikes front wheel.
>
> Are these still available or have they been replaced by the type that run
on
> the back wheel?
>
> An idea of cost would be nice too!
>
> Also can anyone advise me as to the output of these dynamo's and if they
are
> more or less efficient than the type that run on the back wheel?
>
> Cheers all tox

These links should help:

http://www.audax.uk.net/lights/dyno.htm http://www.audax.uk.net/lights/gens.htm

Some of the links out of these pages no longer work.
___
Michael MacClancy

 

[Tony Raven]

Harry Bloomfield wrote:
>
>
> The hub type were more efficient and more reliable when generating, but they still offered a tiny
> amount of resistance when not generating. The friction wheel type tended to slip a little, the
> head and bearings wear out quickly cause more drag than the hub type when in use. When not in use
> they caused no drag.

The best hub dynamos have a drag equivalent to climbing a 1 in 5000 slope (i.e 1ft rise per mile).
For most of us that is effectively no drag.

Tony

 

[Tim Downie]

Crash Bang Wallop wrote:
> I'm looking for a source of bike dynamos, (I require about ten initially) however, I want the old
> fashioned type that reside in the hub of a bikes front wheel.

I can't believe that no one's asked why you need ten and what plans you have for them. ;-)

The cross posting suggests some sort of unconventional use. Do tell.

Tim
--
Remove the obvious to reply by email.

 

[Harry Bloomfiel]

"Tim Downie" wrote on 16/12/2003 :-
> Crash Bang Wallop wrote:
>> I'm looking for a source of bike dynamos, (I require about ten initially) however, I want the old
>> fashioned type that reside in the hub of a bikes front wheel.
>
> I can't believe that no one's asked why you need ten and what plans you have for them. ;-)
>
> The cross posting suggests some sort of unconventional use. Do tell.
>
> Tim

Well, I too would like to know, but didn't like to ask

--
Regards, Harry (M1BYT)...

Remove the 'NOSPAM' in my email address to reply.

Free Amateur Radio Courses:- http://www.ukradioamateur.org

 

[Helen Deborah V]

"Tim Downie" <[email protected]>typed

> Crash Bang Wallop wrote:
> > I'm looking for a source of bike dynamos, (I require about ten initially) however, I want the
> > old fashioned type that reside in the hub of a bikes front wheel.

> I can't believe that no one's asked why you need ten and what plans you have for them. ;-)

> The cross posting suggests some sort of unconventional use. Do tell.

Maybe the OP's email address gives a clue...

--
Helen D. Vecht: [email protected] Edgware.

 

[Crash Bang Wall]

"Tony Raven" <[email protected]> wrote in message
news:[email protected]...
> Plenty still available. Shimano and Schmidt are popular. You can get the former for about £25
> upwards. The latter is more expensive. All you need to know about output is at http://www.myra-
> simon.com/bike/dynotest.html
>
> Tony
>

Excellent link Tony, just what I was looking for.

However, I'm somewhat surprised at the cost of these things. Quite frankly, in these days of mass
production, I'd have expected them to cost peanuts, especially when you can go to somewhere such as
Stirling House and buy a fifteen speed bike for under £40! Try http://tinyurl.com/zg2c

Thanks to everyone for such a quick and detailed response.

Regards tox

 

[Pete Biggs]

Tim Downie wrote:
> Crash Bang Wallop wrote:
>> I'm looking for a source of bike dynamos, (I require about ten initially) however, I want the old
>> fashioned type that reside in the hub of a bikes front wheel.
>
> I can't believe that no one's asked why you need ten and what plans you have for them. ;-)
>
> The cross posting suggests some sort of unconventional use. Do tell.

Maybe Mr Wallop is the fantastic bloke I once saw in Kilburn, N London, with a massive sound and
light system on his bike. I didn't notice how many front wheels the machine had because I was
dazzled by his space age track-style silver helmet and visor. Respec'!!

~PB

 

[Crash Bang Wall]

"Tim Downie" <[email protected]> wrote in message
news:[email protected]...
>
> The cross posting suggests some sort of unconventional use. Do tell.
>

Hi Tim, I'm sorry to say, I can't say right now as posting details on the Internet would almost
certainly compromise what I have in mind.

Suffice to say, if my idea is a non-runner, I'll post back and let you know what it's all about.

Sorry for the cross posting but as someone who follows uk.r.a. constantly, I've learned there are
some extremely knowledgeable people, on a whole raft of subjects, who reside there and as the forum
would suggest, particularly electronics.

HTH Regards tox

 

[Tony Raven]

Crash Bang Wallop wrote:
>
> However, I'm somewhat surprised at the cost of these things. Quite frankly, in these days of mass
> production, I'd have expected them to cost peanuts, especially when you can go to somewhere such
> as Stirling House and buy a fifteen speed bike for under £40! Try http://tinyurl.com/zg2c
>

Assuming you are coming from ura, not urc, that is equivalent to a cyclist telling you you can buy a
radio for less than a fiver from Sterling House so why do yours cost so much? If you want a cheap
rim dynamo they can be had for about £4 but the hub ones tend to be used only by enthusiasts who are
generally picky about performance, reliability, weight, drag etc so sell in limited quantities to
discerning users. Hence the price.

Tony

 

[Peter Clinch]

Crash Bang Wallop wrote:

> However, I'm somewhat surprised at the cost of these things. Quite fran=
kly,
> in these days of mass production, I'd have expected them to cost peanut=
s,
> especially when you can go to somewhere such as Stirling House and buy =
a
> fifteen speed bike for under =A340!

"Anything free is likely to be worth what you paid for it"[1]. Anything =

which costs next to nothing will be about as good a lot of the time, but =

will cost you some money into the bargain, and often more time as it=20 takes you a bit longer to
give up on it and direct it to a well deserved =

place in the nearest skip.

Good dynamos are compact, reliable, efficient and precision engineered=20 from quality components,
the sort of bikes one gets at Sterling House,=20 AFAICT, aren't.

There just isn't any point in making cheap and nasty hub dynamos, when=20 the wheel building costs
will have to be factored in above the base=20 costs of the unit.

Pete.

[1] fortunately many good pieces of software are notable exceptions --=20 Peter Clinch University of
Dundee Tel 44 1382 660111 ext. 33637 Medical Physics, Ninewells Hospital Fax 44 1382 640177
Dundee DD1 9SY Scotland UK net [email protected] http://www.dundee.ac.uk/~pjclinch/

 

[Crash Bang Wall]

"Harry Bloomfield" <[email protected]> wrote in message
news:[email protected]...
>
> Well, I too would like to know, but didn't like to ask

;-)

BTW, did you see Lidl are doing those soldering irons for just £2.99!
http://www.lidl.co.uk/gb/index.nsf/pages/c.o.oow.20031215.p.Soldering_Gun

Only in Wales though :-(

Best Wishes tox

 

[Tim Downie]

Crash Bang Wallop wrote:
> "Tim Downie" <[email protected]> wrote in message news:[email protected]
> berlin.de...
>>
>> The cross posting suggests some sort of unconventional use. Do tell.
>>
>
> Hi Tim, I'm sorry to say, I can't say right now as posting details on the Internet would almost
> certainly compromise what I have in mind.

Do I smell a patent in the offing?

> Suffice to say, if my idea is a non-runner, I'll post back and let you know what it's all about.

Does this mean that if it's a runner we'll never hear from you again or just until you've got the
patent sorted out?

> Sorry for the cross posting but as someone who follows uk.r.a. constantly, I've learned there are
> some extremely knowledgeable people, on a whole raft of subjects, who reside there and as the
> forum would suggest, particularly electronics.

Oh, don't apologise, you might even have considered uk.d-i-y. Experts on just about every known
subject there.

Just out of curiosity, are these ten dynamos going to be fitted to a single device or ten different
ones? (If you are considering patenting, I won't be offended if you prefer not to answer).

Cheers.

Tim

--
Remove the obvious to reply by email.

 

[Crash Bang Wall]

"Helen Deborah Vecht" <[email protected]> wrote in message
news:[email protected]...
>
> Maybe the OP's email address gives a clue...

ROTFL, yep, it's time I changed it, Helen...watch this space ;-)

Regards tox

 

[Tony Raven]

Crash Bang Wallop wrote:
>
> Hi Tim, I'm sorry to say, I can't say right now as posting details on the Internet would almost
> certainly compromise what I have in mind.
>

He's obviously building the bicycle racing machine from Belleville Rendezvous and needs them to
power the projector ;-)

Tony

 

[Crash Bang Wall]

"Tony Raven" <[email protected]> wrote in message
news:[email protected]...
> Assuming you are coming from ura, not urc, that is equivalent to a cyclist telling you you can buy
> a radio for less than a fiver from Sterling House
so
> why do yours cost so much? If you want a cheap rim dynamo they can be had
for
> about £4 but the hub ones tend to be used only by enthusiasts who are generally picky about
> performance, reliability, weight, drag etc so sell
in
> limited quantities to discerning users. Hence the price.
>

Sorry Tony, however, it' nearly forty years since I owned a bike and then it was only to do a
paper round!

Eight bob a week is what I was paid IIRC and two bob of that went towards paying for the bike...eeee
'twere 'ard in thowas days ;-)

Regards tox