Re: Schmidt dynamo hubs

Alan Braggins said the following on 21/11/2006 09:23:

Quoted message said:

General opinion seems to be that the better Shimano hubs are very nearly as
good as the SON for half the price, but there are uk.rec.cycling posters
who have used both and can give you a better answer.

....like don't get the Nexus dynohub. The lowest spec Shimano dynohub to
use is the 3N71, which is what I have. I'm sure the SON hubs are
better, but quite frankly the 3N71 doesn't need to be any better, so why
pay more? I get lots of light at low speed and any drag is unnoticeable
with the lights on or off.

http://tinyurl.com/y2nt89 is the one, and the BoB also sell it built
into a wheel.

--
Paul Boyd
http://www.paul-boyd.co.uk/

"Paul Boyd" <usenet.dont.work@plusnet> wrote in message
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Quoted message said:

Alan Braggins said the following on 21/11/2006 09:23:

Quoted message said:

General opinion seems to be that the better Shimano hubs are very nearly
as
good as the SON for half the price, but there are uk.rec.cycling posters
who have used both and can give you a better answer.

...like don't get the Nexus dynohub.

You said this last time. I disagree. IIRC you havn't actually tried the
Nexus dynohub.

I've actually got the original Shimano dynohub - the NX10. I used it for
several years and a couple of tens of thousands of miles. This one is
notable for being the worst example of a dynohub which Shimano made - ie all
the new ones are better. And it's actually pretty good. Drag isn't
noticable, on or off, and it gives as much light as my SON.

So while it's worth knowing the posher ones are better, there's no need to
run away from the cheaper ones if money is tight.

cheers,
clive

Paul Boyd said:

...like don't get the Nexus dynohub. The lowest spec Shimano dynohub to
use is the 3N71, which is what I have. I'm sure the SON hubs are
better, but quite frankly the 3N71 doesn't need to be any better, so why
pay more?

As with any hub, better construction quality should probably give a
longer trouble free life: pay more now, faff again later. But having
said that there's certainly no indication from Roos' 3N71 on her hack
bike that serious short-cuts were taken with the build.

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

Peter Clinch said:

Paul Boyd said:

...like don't get the Nexus dynohub. The lowest spec Shimano dynohub to
use is the 3N71, which is what I have. I'm sure the SON hubs are
better, but quite frankly the 3N71 doesn't need to be any better, so why
pay more?

As with any hub, better construction quality should probably give a
longer trouble free life: pay more now, faff again later. But having
said that there's certainly no indication from Roos' 3N71 on her hack
bike that serious short-cuts were taken with the build.

I switched to the SON after the bearings gave up on the Shimano: I was
able to fix the LH race, but couldn't figure out how to change the RH
side bearings, which are entirely banjaxed. They lasted about two
years, though (SON now done more than that and running sweetly).

Clive George said the following on 21/11/2006 10:51:

Quoted message said:

You said this last time. I disagree. IIRC you havn't actually tried the
Nexus dynohub.

No, I went by performance graphs and specifications, as with anything
else in life. Drag on the Nexus was higher than the others (IIRC, it
was Chris Juden who measured these, amongst others), and the crunch was
that over about 15mph, there was *more* drag with the lights turned off
than with them on, and whether on or off had more drag than pretty much
any other hub. I cycle at more than 15mph...

--
Paul Boyd
http://www.paul-boyd.co.uk/

"Paul Boyd" <usenet.dont.work@plusnet> wrote in message
news:[email hidden]...

Quoted message said:

Clive George said the following on 21/11/2006 10:51:

Quoted message said:

You said this last time. I disagree. IIRC you havn't actually tried the
Nexus dynohub.

No, I went by performance graphs and specifications, as with anything else
in life. Drag on the Nexus was higher than the others (IIRC, it was Chris
Juden who measured these, amongst others), and the crunch was that over
about 15mph, there was *more* drag with the lights turned off than with
them on, and whether on or off had more drag than pretty much any other
hub. I cycle at more than 15mph...

So do I. IME the drag appears to be slightly more with them on than off -
contrary to the graphs. (normally produced by tbe maker of SON btw).

Your beef with the lower end shimano stuff seems to be rather more forceful
than is justified - like I said, I've actually used their worst one for
ages, and it's definitely worth considering if money is tight. It's not the
'run away screaming' option you keep saying it is.

What it probably comes down to is that the drag isn't actually really
perceptible in real life. Eg the SON may be twice as good - but 2xbugger all
is still bugger all, if you see what I mean.

cheers,
clive

Clive George said the following on 21/11/2006 12:52:

Quoted message said:

Your beef with the lower end shimano stuff seems to be rather more
forceful than is justified - like I said, I've actually used their worst
one for ages, and it's definitely worth considering if money is tight.

I didn't realise I had a beef! I have a variety of low-end Shimano
stuff where it does the job, and IMO the Nexus doesn't do what I want it
to do. Not having money to spare to try a variety of hubs, I asked this
group for advice. I was pointed at several independent sites (with no
connection to SON), and the data on those sites helped me to make up my
own mind. My conclusion was the same as the pretty unanimous verdict
here - don't go for the Nexus hub.

Quoted message said:

It's not the 'run away screaming' option you keep saying it is.

I think you're confusing attributions. "don't get" is hardly the same
as "run away screaming", is it?

--
Paul Boyd
http://www.paul-boyd.co.uk/

Paul Boyd usenet.dont.work@plusnet said:

No, I went by performance graphs and specifications, as with anything
else in life. Drag on the Nexus was higher than the others (IIRC, it
was Chris Juden who measured these, amongst others), and the crunch was
that over about 15mph, there was *more* drag with the lights turned off
than with them on, and whether on or off had more drag than pretty much
any other hub. I cycle at more than 15mph...

So leave them on? I have an NX30 (I think, the only 3W one there was in
2002) and it powers my lights all the time - there's no off switch. There's
a little drag (it feels a little notchy at about 18mph) but it's perfectly
acceptable and doesn't make it very much more work. Having lights on in
daytime gives the impression that traffic gives a wider berth too, though
it's difficult to measure this.

My only bulb blows (and a fried rear LED) were because of loose connections
that dumped all the power into one lamp. This is fixable with a zener
diode limiter across the hub:

+ --+----|>|----T<|---+---- -
| |
+----|<|----|>T---+

Where |>| is a normal silicon diode (1N4001 or similar) and T<| is a zener
of about 5.3V. Since fitting that I had no more bulb damage.

Theo

Clive George said:

So do I. IME the drag appears to be slightly more with them on than off
- contrary to the graphs. (normally produced by tbe maker of SON btw).

Many people have independently tested the efficiency of dynohubs, and
I've yet to see results which contradict the findings of Wilfried
Schmidt and Andreas Oehler

--
---
Marten Gerritsen

INFOapestaartjeM-GINEERINGpuntNL
www.m-gineering.nl

"Paul Boyd" <usenet.dont.work@plusnet> wrote in message
news:[email hidden]...

Quoted message said:

Clive George said the following on 21/11/2006 12:52:

Quoted message said:

Your beef with the lower end shimano stuff seems to be rather more
forceful than is justified - like I said, I've actually used their worst
one for ages, and it's definitely worth considering if money is tight.

I didn't realise I had a beef! I have a variety of low-end Shimano stuff
where it does the job, and IMO the Nexus doesn't do what I want it to do.
Not having money to spare to try a variety of hubs, I asked this group for
advice. I was pointed at several independent sites (with no connection to
SON), and the data on those sites helped me to make up my own mind. My
conclusion was the same as the pretty unanimous verdict here - don't go
for the Nexus hub.

It isn't a unanimous verdict - my contribution has always been "the Nexus
hub is fine". And remember it is based on experience - I've done a lot of
miles on what are supposed to be the best (SON) and the worst (NX-10), and I
think that's given me a pretty good idea of the differences - not much.

Quoted message said:

Quoted message said:

It's not the 'run away screaming' option you keep saying it is.

I think you're confusing attributions. "don't get" is hardly the same as
"run away screaming", is it?

The way you say it, yes it is. You don't leave any room for doubt or
compromise with that statement. "Don't get unless you can't afford the
expensive one", or just "the expensive one is better" would be better.

What I'm trying to do is not put people off having a dynohub by saying 'only
get the expensive one', whereas the cheap ones are almost as good. I'd not
hesitate to fit the cheapest shimano one to a hack bike.

cheers,
clive

Theo Markettos said:

So leave them on? I have an NX30 (I think, the only 3W one there was in
2002) and it powers my lights all the time - there's no off switch. There's
a little drag (it feels a little notchy at about 18mph) but it's perfectly
acceptable and doesn't make it very much more work. Having lights on in
daytime gives the impression that traffic gives a wider berth too, though
it's difficult to measure this.

Interesting; I have an NX10 (I was alway into
hub dynamos, had several Sturmey Archer ones).

It's "notchy" (e.g. resonates the entire front end
of the bike) at 14 mph.

I try not to travel at this speed :-)

BugBear

Clive George said:

What it probably comes down to is that the drag isn't actually really
perceptible in real life. Eg the SON may be twice as good - but 2xbugger
all is still bugger all, if you see what I mean.

Seconded.
I have a Shimano Nexus 3R40, used for about a year with no problems, I
don't notice the drag when cycling, It does not feel notchy to me, and
if I had the money I would probably buy a second shimano dynohub for my
other bike.

Martin.

Paul Boyd said:

Clive George said the following on 21/11/2006 10:51:

Quoted message said:

You said this last time. I disagree. IIRC you havn't actually tried the
Nexus dynohub.

No, I went by performance graphs and specifications, as with anything
else in life. Drag on the Nexus was higher than the others (IIRC, it
was Chris Juden who measured these, amongst others), and the crunch was
that over about 15mph, there was *more* drag with the lights turned off
than with them on

That's the early Nexus hub (NX-10) and the newer NX-32 isn't as bad.
The 3N30 is about the same efficiency as the 3N70.
http://www.vintagebicyclepress.com/VBQgenerator.pdf
http://www.nabendynamo.de/pdf/ar.1-2_2005.pdf
http://www.crazyguyonabike.com/forum/board/message/?o=lt&board_id=389&sequence=33&v=6g

Martin Dann said the following on 21/11/2006 15:26:

Quoted message said:

I have a Shimano Nexus 3R40

That's a different beasty to the NX10 that we were talking about.

--
Paul Boyd
http://www.paul-boyd.co.uk/

"Paul Boyd" <usenet.dont.work@plusnet> wrote in message
news:[email hidden]...

Quoted message said:

Martin Dann said the following on 21/11/2006 15:26:

Quoted message said:

I have a Shimano Nexus 3R40

That's a different beasty to the NX10 that we were talking about.

Ah! But it's a Nexus dynohub.

So, to clarify, is it _all_ nexus dynohubs you object to, or just the
original NX10? It makes a bit of a difference, because the NX10 was replaced
quite a long time ago - and AFAIK the replacements are all better.

cheers,
clive

["Followup-To:" header set to uk.rec.cycling.]

Alan Braggins said:

Paul Boyd said:

Clive George said the following on 21/11/2006 10:51:

Quoted message said:

You said this last time. I disagree. IIRC you havn't actually tried the
Nexus dynohub.

No, I went by performance graphs and specifications, as with anything
else in life. Drag on the Nexus was higher than the others (IIRC, it
was Chris Juden who measured these, amongst others), and the crunch was
that over about 15mph, there was *more* drag with the lights turned off
than with them on

That's the early Nexus hub (NX-10) and the newer NX-32 isn't as bad.
The 3N30 is about the same efficiency as the 3N70.

Since there are clearly people here who have memorised the performance
parameters - which is the best hub dynamo compatible with a shimano
nexus roller brake?

Of the Shimano dynamos, the options seem to be 3R40 and 2R30, but from
the limited information on the Shimano website, I don't know what the
difference is.

regards, Ian SMith
--
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|o o|
|/ \|

Ian Smith said:

["Followup-To:" header set to uk.rec.cycling.]
On 21 Nov 2006, Alan Braggins <[email hidden]> wrote:

Quoted message said:

which is the best hub dynamo compatible with a shimano
nexus roller brake?

Of the Shimano dynamos, the options seem to be 3R40 and 2R30, but from
the limited information on the Shimano website, I don't know what the
difference is.

The 2R40 provides 2.4W of power, the 3R40 3W.
Therefore the 3R40 is the better of the two, and is the one I have.
Wiggle sell the latter for 45ukp (if you buy something else there).

Martin.

Martin Dann said:

Ian Smith said:

["Followup-To:" header set to uk.rec.cycling.]
On 21 Nov 2006, Alan Braggins <[email hidden]> wrote:

Quoted message said:

which is the best hub dynamo compatible with a shimano
nexus roller brake?

Of the Shimano dynamos, the options seem to be 3R40 and 2R30, but from
the limited information on the Shimano website, I don't know what the
difference is.

The 2R40 provides 2.4W of power, the 3R40 3W.
Therefore the 3R40 is the better of the two, and is the one I have.
Wiggle sell the latter for 45ukp (if you buy something else there).

Is that all the difference, however? If, for example, the 2.4W were
2.4W but lower drag / longer life / smoother feeling, I might prefer
the 2.4W one.

The dynamo would tend to be unexpected use only - all my utility bikes
(with the exception of the newest, which is what I am now thinking of)
have had battery primary lights, but a dynamo fitted for the occasions
when I accidently stay out 'till after dark despite intentions
otherwise, and have neglected to have batteries about my person.

regards, Ian SMith
--
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|o o|
|/ \|

M-gineering said:

Many people have independently tested the efficiency of dynohubs, and
I've yet to see results which contradict the findings of Wilfried
Schmidt and Andreas Oehler

Try 'test' magazine, issue 03/2006 :-)
It is a good thing that their online content is not available for free.
This somehow limits the spread of their seriously flawed figures which
stem from basic errors in the testing setup.

f'up2 uk.rec.cycling

Günther