another question about dynamos

[davek]

The [limited] instructions for the Nordlicht dynamo indicate that it
should be fitted on the right hand side in front of the fork.

Unfortunately, I don't have space to fit it there, so I fitted it on
the /left/ hand side /behind/ the fork. In that position, the cap will
be rotated in the same direction as it would be in the right/front
position, but is there any reason why fitting the dynamo behind the
fork might be A Bad Idea?

d.

 

[David Martin]

On 12/4/05 9:25 am, in article
[email protected], "davek"
<[email protected]> wrote:

> The [limited] instructions for the Nordlicht dynamo indicate that it
> should be fitted on the right hand side in front of the fork.
>
> Unfortunately, I don't have space to fit it there, so I fitted it on
> the /left/ hand side /behind/ the fork. In that position, the cap will
> be rotated in the same direction as it would be in the right/front
> position, but is there any reason why fitting the dynamo behind the
> fork might be A Bad Idea?

If things go seriously pear shaped then the dynamo could conceivably be
dragged into the forks and jam the front wheel. With the dynamo on the other
side it would be dragged away and out from the front wheel.

Only thing I can think of right now.

...d

 

[Another group member]

Its actually a good idea to fit behind the fork as rotating wheel will press
dynamo more tightly to the trye.
John.

--


http://www.photobox.co.uk/album/1170117
"davek" <[email protected]> wrote in message
news:[email protected]...
> The [limited] instructions for the Nordlicht dynamo indicate that it
> should be fitted on the right hand side in front of the fork.
>
> Unfortunately, I don't have space to fit it there, so I fitted it on
> the /left/ hand side /behind/ the fork. In that position, the cap will
> be rotated in the same direction as it would be in the right/front
> position, but is there any reason why fitting the dynamo behind the
> fork might be A Bad Idea?
>
> d.
>

 

[davek]

David Martin wrote:
> If things go seriously pear shaped then the dynamo could conceivably
be
> dragged into the forks and jam the front wheel.

Oo-er! Doesn't sound so good. I could always fit it to the rear wheel
(space allowing) but that would be a pain as I'm only running a front
light off it.

d.

 

[davek]

John wrote:
> Its actually a good idea to fit behind the fork as rotating wheel
will press
> dynamo more tightly to the trye.

Interesting, thanks. But does that also mean it will wear out the tyre
quicker?

d.

 

[dkahn400]

davek wrote:

> The [limited] instructions for the Nordlicht dynamo indicate that
> it should be fitted on the right hand side in front of the fork.
>
> Unfortunately, I don't have space to fit it there, so I fitted it
> on the /left/ hand side /behind/ the fork. In that position, the
> cap will be rotated in the same direction as it would be in the
> right/front position...

Mounted on the right side the cap will rotate clockwise when viewed
from above. On the left side it will rotate anti-clockwise. This is
true whether it's mounted in front of the fork or behind it. Whether
this actually matters I have no idea.

--
Dave...

 

[Jon Schneider]

"davek" <[email protected]> writes:

> any reason why fitting the dynamo behind the
> fork might be A Bad Idea?

It might turn the wrong way and the bulb would start sucking ambient
light in.

Jon

 

[davek]

dkahn400 wrote:
> Mounted on the right side the cap will rotate clockwise when viewed
> from above. On the left side it will rotate anti-clockwise.

Yes, you're right. For some reason I had got it into my head that
putting it behind the fork would necessitate changing which side it
went on.

> Whether
> this actually matters I have no idea.

Well.... it seems to work OK the "wrong" way round. But then I could
just be on my way to breaking it very quickly...

d.

 

[Tim Hall]

On 12 Apr 2005 07:04:36 -0700, "davek" <[email protected]>
wrote:

>dkahn400 wrote:
>> Mounted on the right side the cap will rotate clockwise when viewed
>> from above. On the left side it will rotate anti-clockwise.
>
>Yes, you're right. For some reason I had got it into my head that
>putting it behind the fork would necessitate changing which side it
>went on.
>
>> Whether
>> this actually matters I have no idea.
>
>Well.... it seems to work OK the "wrong" way round. But then I could
>just be on my way to breaking it very quickly...
>

The electricity will be made backwards, so the light will suck up the
darkness rather than throw a beam of light.


On the other, more sensible, hand, I've had a dynamo mounted exactly
as you describe with no problem. The idea, as John said up there ^,
is to drag the dynamo towards the tyre with the rotation.

I've gone all posh now though, and got a hub dynamo.


Tim

 

[davek]

Jon Schneider wrote:
> It might turn the wrong way and the bulb would start sucking ambient
> light in.

Is this the fastest (and cheapest) way to convert to the Dark Side?

d.

 

[MartinM]

Jon Schneider wrote:
> "davek" <[email protected]> writes:
>
> > any reason why fitting the dynamo behind the
> > fork might be A Bad Idea?
>
> It might turn the wrong way and the bulb would start sucking ambient
> light in.

I notice sjs are selling one which attaches outside the rear hub, so
you don't need to re-hub the wheel; anyone have experience of this? was
thinking of getting one as I don't much like fork mount ones and this
seems the same price as a good one.

 

[Clive George]

"MartinM" <[email protected]> wrote in message
news:[email protected]...
> I notice sjs are selling one which attaches outside the rear hub, so
> you don't need to re-hub the wheel; anyone have experience of this? was
> thinking of getting one as I don't much like fork mount ones and this
> seems the same price as a good one.

They're also flogging an NX-32 front hub and switch for 45 quid. Bargain
(though remember to get a front light or something at the same time to bring
it over 50 quid.

Ok, you'll need to build it into a wheel, but front wheels aren't too hard,
and when you've done it you've got a proper system. As you say, the pioneer
thing is the same price as a good one - so get a good one!

When I got my first dynohub about 6 or 7 years ago, I thought I'd take it
off for summer. Despite being the shimano NX-10, reputedly one of the
draggiest ones you could get, I never did - the drag still wasn't noticable.

cheers,
clive

 

[David Martin]

On 13/4/05 12:01 pm, in article
[email protected], "Clive George"
<[email protected]> wrote:

> "MartinM" <[email protected]> wrote in message
> news:[email protected]...
>> I notice sjs are selling one which attaches outside the rear hub, so
>> you don't need to re-hub the wheel; anyone have experience of this? was
>> thinking of getting one as I don't much like fork mount ones and this
>> seems the same price as a good one.

> Ok, you'll need to build it into a wheel, but front wheels aren't too hard,
> and when you've done it you've got a proper system. As you say, the pioneer
> thing is the same price as a good one - so get a good one!

This has me thinking. I am converting an old bike to a fixed and it needs
real rims instead of the chrome ones it has. It is tempting to go the whole
hog and get a dynohub which is then easily transferred to the other bike if
needed.. Not sure SWMBO would be persuaded.

...d

 

[MartinM]

David Martin wrote:
> On 13/4/05 12:01 pm, in article
> [email protected], "Clive George"
> <[email protected]> wrote:
>
> > "MartinM" <[email protected]> wrote in message
> > news:[email protected]...
> >> I notice sjs are selling one which attaches outside the rear hub,
so
> >> you don't need to re-hub the wheel; anyone have experience of
this? was
> >> thinking of getting one as I don't much like fork mount ones and
this
> >> seems the same price as a good one.
>
> > Ok, you'll need to build it into a wheel, but front wheels aren't
too hard,
> > and when you've done it you've got a proper system. As you say, the
pioneer
> > thing is the same price as a good one -

I meant a good bottle dynamo; not sure about building it around a hub,
I do very little night riding; need something for long audaxes and of
course the Dun Run although the full moon will help there. No way I
could build the wheel myself and my front wheel rim is starting to wear
out anyway. The pseudo -hub dynamo seems ideal but I wanted an opinion
from anyone who had used it.

 

[Simon Proven]

davek wrote:
> The [limited] instructions for the Nordlicht dynamo indicate that it
> should be fitted on the right hand side in front of the fork.
>
> Unfortunately, I don't have space to fit it there, so I fitted it on
> the /left/ hand side /behind/ the fork. In that position, the cap will
> be rotated in the same direction as it would be in the right/front
> position, but is there any reason why fitting the dynamo behind the
> fork might be A Bad Idea?
>
> d.
>

Consider what would happen if the dynamo bearing seized. Behind the
fork, the dynamo would tend to be pulled into the tyre, whereas in
front of the fork it would tend to be pushed away.

Simon

 

[MartinM]

The pseudo -hub dynamo seems ideal but I wanted an opinion
> from anyone who had used it.

I did eventually find a review on cycling forums about it; seems it is
a bugger to get on and decides to rotate with the wheel from time to
time. What about those ones which work off the rear tyre tread?

 

[Dave Larrington]

MartinM wrote:
> The pseudo -hub dynamo seems ideal but I wanted an opinion
>> from anyone who had used it.
>
> I did eventually find a review on cycling forums about it; seems it is
> a bugger to get on and decides to rotate with the wheel from time to
> time. What about those ones which work off the rear tyre tread?

I used to have one twenty-mumble years ago - a Sanyo Dynapower. A bit prone
to slipping in the wet until coating the roller with a mixture of sand and
araldite. Worked well once I'd worked out that using the frame for the
purposes of conducting electricity is a Bad Thing.

Eventually it seized up, though I imagine current ones will probably have
better bearings.

--
Dave Larrington - <http://www.legslarry.beerdrinkers.co.uk/>
This Unit is a productive Unit.

 

[Simon Brooke]

in message <[email protected]>,
MartinM ('[email protected]') wrote:

> I did eventually find a review on cycling forums about it; seems it is
> a bugger to get on and decides to rotate with the wheel from time to
> time. What about those ones which work off the rear tyre tread?

The ones which fit under the bottom bracket and operate on the centre of
the tread? I've used (and worn out) about half a dozen of those
(Sanyos). What's good about them: they're neat and tidy and don't
clutter up the look of the bike; they work on the centre of the tread
so don't bugger up your sidewalls; and they work very well. What's bad
about them: road grit eventually wears through the drum, at which point
they are unusable and not repairable. I would guess that each did at
least 3,000 miles of night riding before failing.

These days I would get a hub dynamo; in those days I thought it would
spoil the look of the bike too much.

--
[email protected] (Simon Brooke) http://www.jasmine.org.uk/~simon/

;; Want to know what SCO stands for?
;; http://ars.userfriendly.org/cartoons/?id=20030605

 

[[email protected]]

MartinM wrote:
> I notice sjs are selling one which attaches outside the rear hub, so
> you don't need to re-hub the wheel; anyone have experience of this?
was
> thinking of getting one as I don't much like fork mount ones and this
> seems the same price as a good one.

The pioneer one? I have one. It fouled the chainstay on my main bike
and I had to shave a bite out of the plastic casing and also tape[1]
the outside edge of the casing to the chainstay to stop it rotating
(being clamped between the dropout and end of the axle is supposed to
do this). The lamps have no standlights. The bearing is pretty crappy
and a little noisy. It offers rather more resistance than a loaded
nexus hub dynamo (when loaded) and doesn't offer any less when the
lights are switched off. I demoted it to my second bike which is a
cheaper hybrid that is used primarily for hauling children on shorter
journeys.

I am much happier with my nexus hub although after blowing three or
four sw-nx30 switches in close succession and running without a switch
for 6 months I have settled on a sw-nx10 switch.

Having said that, when I got it I thought it was great compared to
battery lights for commuting, I didn't feel as though riding was harder
work (although my commute time increased by 1-2 minutes on a 25 minute
ride). I guess it compares pretty much to a cheap bottle dynamo
without slippage but without the ability to disengage. Fitting it was
a pain.

best wishes
james

[1] superglue a ziptie around the outside edge of the casing, gaffer
tape the tail of the ziptie to the chainstay. This did the job

 

[MartinM]

[email protected] wrote:
> MartinM wrote:
> > I notice sjs are selling one which attaches outside the rear hub,
so
> > you don't need to re-hub the wheel; anyone have experience of this?
> was
> > thinking of getting one as I don't much like fork mount ones and
this
> > seems the same price as a good one.
>
> The pioneer one? I have one.

I don't need the lights (was going to use the twin set off my Smart set
and LED rear)so am loathe to buy the whole kit, and from what you are
saying it is more trouble than it is worth, unless I can find just the
dynamo unit. One reason I don't want to buy a bottle 'mo is that I
don't want to slice the mudguards up to fit it. I could use a LiIon
battery with the Smart set I s'pose.