shaft drive ?
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On page 13 of the Sunday Times business section yesterday there was a picture of a japanese minister
riding a bicycle with a shaft drive ! Has anyone seen these ? A good idea ?
maf
"maf" <m.ferenczi@imperial.ac.uk> wrote in message news:bk3shq$e0b$1@jura.cc.ic.ac.uk...
> On page 13 of the Sunday Times business section yesterday there was a picture of a japanese
> minister riding a bicycle with a shaft drive ! Has anyone seen these ? A good idea ?
Yes -- seen similar.
Generally less efficient than a conventional chain -- but potentially a 'clean' drive with less bits
to grab your Gucci suit -- not that many cycle in their Gucci suit!!
T
maf must be edykated coz e writed:
> On page 13 of the Sunday Times business section yesterday there was a picture of a japanese
> minister riding a bicycle with a shaft drive ! Has anyone seen these ? A good idea ?
>
> maf
>
There was an article about them in the last edition of Velovision.
http://www.velovision.co.uk/cgi-bin/show_comments.pl?storynum=507
--
Ian
http://www.catrike.co.uk (http://www.catrike.co.uk/)
maf wrote:
> On page 13 of the Sunday Times business section yesterday there was a picture of a japanese
> minister riding a bicycle with a shaft drive ! Has anyone seen these ? A good idea ?
>
> maf
Probably a Bridgestone or Panasonic neither of which AFAIK has been sold outside Japan. You can find
an example of a Bridgestone one at http://www.bscycle.co.jp/catalog/folding-compact/transit-scx.html
There was a range of UK shaft drive bikes on show at the York Rally this year. Rode one round the
compound and it seemed OKish but it was not really possible to judge much in the circumstances.
Tony
--
"If you tell the truth you don't have to remember anything." Mark Twain
maf <m.ferenczi@imperial.ac.uk> writes:
> On page 13 of the Sunday Times business section yesterday there was a picture of a japanese
> minister riding a bicycle with a shaft drive ! Has anyone seen these ? A good idea ?
Frankly, no.
With shaft drive you have to have two sets of bevel gears each turning the drive through
approximately ninety degrees. The efficiency losses in the two gearboxes are much greater than the
losses in chain drive, and that's before you start getting into variable speed.
The gears also have to be relatively small so the forces on the teeth are extremely high, which
means wear is likly to be high. Furthermore, extracting the rear wheel is going to be a lot more
complex, because the exact positioning of the gears is critical.
The deraileur gear system may seem incredibly crude. It _is_ incredibly crude, and the exposed chain
does suffer from dirt, grit, and loss of lubricant. But in terms of energy transfer it is
exceptionally efficient, and its very crudity makes it relatively tolerant of slight variations in
rear wheel position, making hand assembly and disassembly unproblematic.
There are a nujmber of manufacturers of shaft drive bikes around, some of them UK based. However in
my opinion these machines are more or less a gimmick.
--
simon@jasmine.org.uk (Simon Brooke) http://www.jasmine.org.uk/~simon/
Anagram: I'm soon broke.
Ian wrote:
> There was an article about them in the last edition of Velovision.
>
> http://www.velovision.co.uk/cgi-bin/show_comments.pl?storynum=507
More than that, it's a full test of an actual example you can swap for money in the UK.
Pete (still waiting for the new VV to land on his doormat).
--
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 p.j.clinch@dundee.ac.uk
http://www.dundee.ac.uk/~pjclinch/
Simon Brooke <simon@jasmine.org.uk> wrote:
> Furthermore, extracting the rear wheel is going to be a lot more complex, because the exact
> positioning of the gears is critical.
>
> The deraileur gear system may seem incredibly crude. It _is_ incredibly crude, and the exposed
> chain does suffer from dirt, grit, and loss of lubricant. But in terms of energy transfer it is
> exceptionally efficient, and its very crudity makes it relatively tolerant of slight variations in
> rear wheel position, making hand assembly and disassembly unproblematic.
Really? I have owned both shaft and chain driven motorbikes and the shaft drive bikes have been
implicity themselves to remove the rear wheel from , with ( from memory) only one bolt needing to be
removed to enable to rear wheel to be lifted off. As to the energy transfer the efficiency of a
chain is only there when it is new, as soon as it starts to suffer from "dirt, grit, and loss of
lubricant." plus the wear from the above the efficiency drops, whereas the shaft has the same values
almost forever.
--
Marc Stickers,decals,membership,cards, T shirts, signs etc for clubs and associations of all types.
http://www.jaceeprint.demon.co.uk/
In article <3F657E80.8060005@dundee.ac.uk>, p.j.clinch@dundee.ac.uk says...
> Ian wrote:
>
> > There was an article about them in the last edition of Velovision.
> >
> > http://www.velovision.co.uk/cgi-bin/show_comments.pl?storynum=507
>
> More than that, it's a full test of an actual example you can swap for money in the UK.
I was chatting to a bloke on a train a few months ago---having a Brompton always gets people
talking---and he had just bought his wife a shaft-driven bike. He and she seemed quite pleased with
it but at that time I think it was brand new. If I bump into him again I'll ask how she's getting
along with it.
> Pete (still waiting for the new VV to land on his doormat).
Mine landed at the weekend. As usual it is a great read.
Colin
marc@jaceeprint.demon.co.uk (marc) writes:
> Simon Brooke <simon@jasmine.org.uk> wrote:
>
> > The deraileur gear system may seem incredibly crude. It _is_ incredibly crude, and the exposed
> > chain does suffer from dirt, grit, and loss of lubricant. But in terms of energy transfer it is
> > exceptionally efficient, and its very crudity makes it relatively tolerant of slight variations
> > in rear wheel position, making hand assembly and disassembly unproblematic.
>
> Really? I have owned both shaft and chain driven motorbikes and the shaft drive bikes have been
> implicity themselves to remove the rear wheel from , with ( from memory) only one bolt needing to
> be removed to enable to rear wheel to be lifted off. As to the energy transfer the efficiency of a
> chain is only there when it is new, as soon as it starts to suffer from "dirt, grit, and loss of
> lubricant." plus the wear from the above the efficiency drops, whereas the shaft has the same
> values almost forever.
Uhhhmmmm... no. See recent thread on rct for detailed discussion and actual measurements. An
end-of-life, worn out, filthy, gritty, underlubricated chain is _still_ more efficient than a brand
new shaft drive. On a motorbike this does not matter because you can just add more horsepower at the
engine end. On a pedal cycle you cannot do this.
--
simon@jasmine.org.uk (Simon Brooke) http://www.jasmine.org.uk/~simon/
Anagram: I'm soon broke.
maf wrote:
> On page 13 of the Sunday Times business section yesterday there was a picture of a japanese
> minister riding a bicycle with a shaft drive ! Has anyone seen these ? A good idea ?
>
My LBS had one in for repair a few weeks ago - broken axle on the three speed. It was in ther for
quite a while while they hunted down a longer than standard axle for it.
--
Andrew Pattle
On Mon, 15 Sep 2003 10:21:23 +0100, "Tony Raven" <junk@raven-family.com> wrote:
>There was a range of UK shaft drive bikes on show at the York Rally this year. Rode one round the
>compound and it seemed OKish but it was not really possible to judge much in the circumstances.
>
David Duffield was talking in today's Vuelta coverage about Rover, the car company. Amongst other
things, he said that an early tricycle was shaft driven and that the world's first differential was
invented for the trike. Apparantly, its design was exactly the same as those still used in rear
wheel drive cars today.
James
--
"Sorry mate, I didn't see you" is not a satisfactory excuse.
Simon Brooke <simon@jasmine.org.uk> wrote:
> > > The deraileur gear system may seem incredibly crude. It _is_ incredibly crude, and the exposed
> > > chain does suffer from dirt, grit, and loss of lubricant. But in terms of energy transfer it
> > > is exceptionally efficient, and its very crudity makes it relatively tolerant of slight
> > > variations in rear wheel position, making hand assembly and disassembly unproblematic.
> >
> > Really? I have owned both shaft and chain driven motorbikes and the shaft drive bikes have been
> > implicity themselves to remove the rear wheel from , with ( from memory) only one bolt needing
> > to be removed to enable to rear wheel to be lifted off. As to the energy transfer the efficiency
> > of a chain is only there when it is new, as soon as it starts to suffer from "dirt, grit, and
> > loss of lubricant." plus the wear from the above the efficiency drops, whereas the shaft has the
> > same values almost forever.
>
> Uhhhmmmm... no. See recent thread on rct for detailed discussion and actual measurements. An
> end-of-life, worn out, filthy, gritty, underlubricated chain is _still_ more efficient than a
> brand new shaft drive. On a motorbike this does not matter because you can just add more
> horsepower at the engine end. On a pedal cycle you cannot do this.
I'm willing to accept the power loss theory, but you still haven't justified your assembly bias.
marc@jaceeprint.demon.co.uk (Marc) writes:
> Simon Brooke <simon@jasmine.org.uk> wrote:
>
> > > > The deraileur gear system may seem incredibly crude. It _is_ incredibly crude, and the
> > > > exposed chain does suffer from dirt, grit, and loss of lubricant. But in terms of energy
> > > > transfer it is exceptionally efficient, and its very crudity makes it relatively tolerant of
> > > > slight variations in rear wheel position, making hand assembly and disassembly
> > > > unproblematic.
>
[snip]
>
> I'm willing to accept the power loss theory, but you still haven't justified your assembly bias.
Well, I'd be more prepared to accept benefits of shaft drive on a pedal cycle if it were combined
with a single-sided 'fork' leg (as on recent BMW motor cycles). The fact is you take back wheels of
pedal cycles a lot more often than off motor cycles, mostly because pedal cycle tyres are more
vulnerable to punctures. With a single-sided 'fork' you can change the tyre without taking the tyre
off the bike.
Attaching and detaching a conventional derailleur rear wheel is a matter of flipping one quick
release lever and lifting the wheel out, dropping the wheel back in and flipping the quick release
lever again. This works because the precise positioning of the wheel is not critical. To assemble a
bevel gear, or to assemble the wheel onto splines on a bevel gear already in place, requires at
least more precise lining up and the insertion of at least one bolt. Unless a single-sided rear fork
is used it seems to e inevitable that it must be more complicated.
I have a single-sided 'lefty' front fork on my mountain bike and it works extremely well, so there's
no reason in principle why a single-sided rear fork should not be used.
--
simon@jasmine.org.uk (Simon Brooke) http://www.jasmine.org.uk/~simon/
Anagram: I'm soon broke.
"Tony Raven" <junk@raven-family.com> wrote in message
news:bk40b4$oi7gd$1@ID-178940.news.uni-berlin.de... <snip>
> There was a range of UK shaft drive bikes on show at the York Rally this year. Rode one round the
> compound and it seemed OKish but it was not
really
> possible to judge much in the circumstances.
>
> Tony
couple of UK distributors http://www.zerocycles.co.uk/ http://www.chainlessbikecompany.co.uk/ for
scroll down to see the one from the dark side
cheers -andy
"Simon Brooke" <simon@jasmine.org.uk> wrote in message
news:87ekyhvo97.fsf@gododdin.internal.jasmine.org.uk...
>
> Well, I'd be more prepared to accept benefits of shaft drive on a pedal cycle if it were combined
> with a single-sided 'fork' leg (as on recent BMW motor cycles). The fact is you take back wheels
> of pedal cycles a lot more often than off motor cycles, mostly because pedal cycle tyres are more
> vulnerable to punctures. With a single-sided 'fork' you can change the tyre without taking the
> tyre off the bike.
>
> Attaching and detaching a conventional derailleur rear wheel is a matter of flipping one quick
> release lever and lifting the wheel out, dropping the wheel back in and flipping the quick release
> lever again.
Shaft drive is typically combined with hub gears, for commuting-type bikes. No QR there, even with
chain drive.
cheers, clive
Simon Brooke <simon@jasmine.org.uk> wrote:
> Attaching and detaching a conventional derailleur rear wheel is a matter of flipping one quick
> release lever and lifting the wheel out, dropping the wheel back in and flipping the quick release
> lever again.
Yoiu seem to have forgotten to mention making sure that the chain doesn't hook up with the wheel as
it comes out, and getting the wheel/chain back in position afterwards with the mech in the right
position , a bit more complicated than your version.
>This works because the precise positioning of the wheel is not critical. To assemble a bevel gear,
>or to assemble the wheel onto splines on a bevel gear already in place, requires at least more
>precise lining up and the insertion of at least one bolt.
Or a quick release there is no reason for it to be a bolt anymore than on a convention chain system.
> Unless a single-sided rear fork is used it seems to e inevitable that it must be more complicated.
>
> I have a single-sided 'lefty' front fork on my mountain bike and it works extremely well, so
> there's no reason in principle why a single-sided rear fork should not be used.
We now agree?
marc@jaceeprint.demon.co.uk (Marc) writes:
> Simon Brooke <simon@jasmine.org.uk> wrote:
>
[snip: discussion of merits of chain drive vs shaft drive]
>
> We now agree?
Chain drive is still more efficient by several percentage points, and if there are any sorts of
hills in the way this matters - regardless of your interest in performance. Furthermore a variable
speed gearbox reduces efficiency even further, whereas the awful clunky derailleur mechanism doesn't
(except for chain flexion losses at the 'big-big' and 'small-small' ends of the range, and these are
very small).
I agree that shaft drive has benefits in that the mechanism can be enclosed, both keeping the
mechanism free from external contaminants and your trousers free from being eaten by the chain. And
I'm prepared to accept following our discussion that changing the wheel might be no more difficult.
However, I still think the derailleur, like democracy, is the worst possible mechanism except all
the others. C'est brutal, mais ca marche.
--
simon@jasmine.org.uk (Simon Brooke) http://www.jasmine.org.uk/~simon/
;; no eternal reward will forgive us now for wasting the dawn. ;; Jim Morrison
Simon Brooke wrote:
> However, I still think the derailleur, like democracy, is the worst possible mechanism except all
> the others. C'est brutal, mais ca marche.
Horses == Courses. For example, think of shaft drive and how crap it is when you have to start
cleaning your chain every day when the gritters have been out, because it will sieze up if you
don't... Hacks me off, and I'm not the sort who minds doing that sort of work on the bike. For a
commuter bike used through winter I'd give it some serious thought.
But with a chain, I'd sooner have a Rohloff than a derailleur in any case, at least for what I do.
I'd sooner have a bank balance that could take the strain as well, but that's another issue...
Pete.
--
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 p.j.clinch@dundee.ac.uk
http://www.dundee.ac.uk/~pjclinch/
it seems to e inevitable that it must be more complicated.
I have a single-sided 'lefty' front fork on my mountain bike and it works extremely well, so there's
no reason in principle why a single-sided rear fork should not be used.
--
simon@jasmine.org.uk (Simon Brooke)
Imagine the benefits of a two wheel drive system for mountain biking (shiver).
Simon Brooke <simon@jasmine.org.uk> wrote:
> marc@jaceeprint.demon.co.uk (Marc) writes:
>
> > Simon Brooke <simon@jasmine.org.uk> wrote:
> >
> [snip: discussion of merits of chain drive vs shaft drive]
> >
> > We now agree?
>
> Chain drive is still more efficient by several percentage points, and if there are any sorts of
> hills in the way this matters - regardless of your interest in performance.
Which I had already given you, although for the cheap end of the commuting market I doubt this is a
great problem.
>
> I agree that shaft drive has benefits in that the mechanism can be enclosed, both keeping the
> mechanism free from external contaminants and your trousers free from being eaten by the chain.
Another boon to the commuting market.
>And I'm prepared to accept following our discussion that changing the wheel might be no more
>difficult.
>
> However, I still think the derailleur, like democracy, is the worst possible mechanism except all
> the others. C'est brutal, mais ca marche.
Ahh we do agree then! ;-)
--
Marc Stickers,decals,membership,cards, T shirts, signs etc for clubs and associations of all types.
http://www.jaceeprint.demon.co.uk/
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