Message from discussion Dynamo Hubs - any experience?

Path: g2news1.google.com!news3.google.com!border1.nntp.dca.giganews.com!border2.nntp.dca.giganews.com!nntp.giganews.com!nx02.iad01.newshosting.com!newshosting.com!newsfeed.icl.net!newsfeed.fjserv.net!news-lond.gip.net!news.gsl.net!gip.net!easynet-quince!easynet.net!feed4.jnfs.ja.net!feed2.jnfs.ja.net!jnfs.ja.net!sanger.ac.uk!gemini.csx.cam.ac.uk!news.cam.ac.uk!not-for-mail
From: a...@chiark.greenend.org.uk (Alan Braggins)
Newsgroups: uk.rec.cycling
Subject: Re: Dynamo Hubs - any experience?
Date: 04 Oct 2005 08:08:41 +0100 (BST)
Organization: University of Cambridge, England
Lines: 39
Message-ID: <slrndk4ajm.sln.armb@chiark.greenend.org.uk>
References: <mn.0ccb7d5a7e312097.39715@yahoo.co.uk> <4340552b$0$30840$79c14f64@nan-newsreader-05.noos.net> <slrndk218d.dru.armb@chiark.greenend.org.uk> <43418042$0$19181$79c14f64@nan-newsreader-07.noos.net> <437387e2.500247417@n.nabendynamo.de>
NNTP-Posting-Host: rapun.sel.cam.ac.uk
User-Agent: slrn/0.9.6.2 (Linux)
Originator: a...@chiark.greenend.org.uk ([193.201.200.170])

In article <437387e2.500247...@n.nabendynamo.de>, Andreas Oehler wrote:
>Mon, 3 Oct 2005 21:00:55 +0200, James Thomson:
>
>>"Alan Braggins" <a...@chiark.greenend.org.uk> wrote:
>>
>>> Roseversand don't seem to have the new DH-3D71, only the 70.
>>>
>>http://cycle.shimano-eu.com/publish/content/cycle/seh/nl/en/news___info/news/extremely_light_rotation.html
>>
>>Ah, I wasn't aware of the existence of the DH-3D71.
>
>Forget about the difference between DH-3N70/3D70 and DH-3N71/3D71.
>Measurements by me and other people showed no substential difference in
>drag between both types. The only difference is a little more electrical
>power of the 71's at slow to medium speed.

I suspected Shimano's claims were exaggerated or misleading, but it's good 
to hear actual measurements. Thanks. (But as someone who often travels
at a slow to medium speed, I might bother to go for the 71 anyway.)


>>S>resistance and the result is amazing: They have a 40 % lower rotation 
>>S>friction than the current models (DH-3D70, DH-3N70 and DH-2N70) and 
>
>The amount of mechanical *friction* is relative low.
[...]


>>S>even 75 % less resistance than previous models when the lamp is turned off!
>
>This is true (whithin measurement accuracy). The HB-NX32 takes up about
>8-9 Watt at 30 kmph when switched off.
>The SON28 has a no-load drag of around 1.5 Watt at 30 kmph.

I'd interpreted "previous models" as meaning the 70 range from the previous
sentence. I knew there was an earlier Shimano one that actually had more
drag when turned off at high speed. (I don't know the model number,
http://www.myra-simon.com/bike/dynotest.html says "Inter-L", but you
probably do.)