Near Miss from Trying to Signal

[Colin Blackburn]

On Mon, 10 May 2004 17:50:10 +0200, Elisa Francesca Roselli
<[email protected]> wrote:

>
>
> Colin Blackburn wrote:
>
>> Where are you posting from? This post is xposted to a
>> specifically UK group so opinions of traffic law are
>> bound to differ.
>>
>
> Sorry about the cross-posting.

No problem.

> I enjoy the UK group because I'm often in the UK,
> generally find it easier to shop for cycling related stuff
> there and on UK based Web-sites than in Paris, and many of
> my cycling experiences and experiments specifically
> concern my favorite town of Cambridge.
>
> Behemoth and I, however, live and work in a suburb
> of Paris.

The question was addressed to loki since s/he stated a leagl
point even within the Uk we have different legal systems so
it if worth clarifying where one is from when claiming a
point of law, especially in a crossposted thread.

What does Behemoth do for a living ? ;-)

Colin

 

[Loki]

"Colin Blackburn" <[email protected]> wrote in
message news[email protected]... [...]
> The question was addressed to loki since s/he stated a
> leagl point even within the Uk we have different legal
> systems so it if worth clarifying where one is from
> when claiming a point of law, especially in a
> crossposted thread.

I wasn't claiming a point of law [I'm in Canada btw] It has
always been my understanding that signalling was not
conditional on there being people in the vicinity. If you
are turning you signal. Now I haven't read the local
statutes but it seems like common knowledge hereabouts.
Maybe if I actually did read the Ontario Traffic Act I
would be disabused of my common knowledge assumption...
though I doubt it.

--
'Keep on riding north and west Then circle south and east
Show me beauty but there is no peace.' -rush

 

[David Kerber]

In article <[email protected]>, Elisa.Francesca.Roselli@quadratec-
software.com says...
>
>
> JohnB wrote:
>
> > Firstly ride along in a straight line, take your hand
> > from the bars and just leave your arm hanging loose
> > while you ride while keeping eyes ahead. Usually this is
> > very easy.
>
> It certainly isn't easy for me. I cannot remove my hands
> from the bars at all, not even for a fraction of a second,
> without veering off course. Same for

This certainly sounds like you are constantly pushing or
pulling on the bars with both hands. With both on the
bar, they tend to balance out, though requiring constant
adjustments, but taking one off allows the other one to
suddenly move the wheel. The direction of the initial
veer should tell you whether you are pushing or pulling
on the bars.

I think somebody else's suggestion to consciously try to
relax your hands and arms, and ensure you are putting no
forward or backward force on the grips, may be useful to
you. When you get to that point, you should be able to lift
one hand completely off the bar by a cm or two without it
moving more than a miniscule amount.

--
Remove the ns_ from if replying by e-mail (but keep posts in
the newsgroups if possible).

 

[Johnb]

Mark Tranchant wrote:
>
> Colin Blackburn wrote:
>
> > In the UK there are very few situations (if any?) where
> > a motor vehicle is required to signal if there is no-one
> > around who needs to know. Of course, many drivers fail
> > to signal because they think peds and cyclists don't
> > need to know but that's another matter.
>

> Whilst it is important that one is always aware of
> everyone around, I think it's foolish to assume that
> you've definitely seen everyone who might care about your
> signal - what about the pedestrian behind the parked car,
> for example?

> This technique also encourages habitual correct
> signalling, which can only be a good thing.

A problem with *always* signalling and instilling it into
training, especially with young people is that it can become
more important than reading the road and the conditions. It
is better to emphasise just why one needs to signal.

Of course signalling should always be carried out where it
may affect someone else but to do it *****-nilly breeds a
culture of "when I signal i have right of way" and one much
practised by many motorists :-(

There are also situations where it can be positively
dangerous for a cyclist to signal such as when turning left
when there is a vehicle behind that is intending the same. A
signal may encourage the vehicle to overtake just as the
cyclist is also turning with disastrous and potentially
fatal results.

John B

 

[Old Fart At Pla]

Elisa Francesca Roselli wrote:

> Sorry about the cross-posting. I enjoy the UK group
> because I'm often in the UK, generally find it easier to
> shop for cycling related stuff there and on UK based Web-
> sites than in Paris, and many of my cycling experiences
> and experiments specifically concern my favorite town of
> Cambridge.

Last time I was in Cambridge the bikes were ridden by
psychopaths rather than on cycle paths.

--
Roger.

 

[Jon Senior]

loki [email protected] opined the following...
> I wasn't claiming a point of law [I'm in Canada btw] It
> has always been my understanding that signalling was not
> conditional on there being people in the vicinity. If you
> are turning you signal. Now I haven't read the local
> statutes but it seems like common knowledge hereabouts.
> Maybe if I actually did read the Ontario Traffic Act I
> would be disabused of my common knowledge assumption...
> though I doubt it.

When I took my test (UK) I was told that signalling when
there was no- one to signal to, was an indication that you
weren't aware of your surroundings. As I understand it, a
signal should be to warn someone else of your intentions...
if there is no-one else... don't signal.

Jon

 

[Simon Brooke]

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

>
> "Colin Blackburn" <[email protected]> wrote in
> message news[email protected]... [...]
>> The question was addressed to loki since s/he stated a
>> leagl point even within the Uk we have different legal
>> systems so it if worth clarifying where one is from when
>> claiming a point of law, especially in a crossposted
>> thread.
>
> I wasn't claiming a point of law [I'm in Canada btw] It
> has always been my understanding that signalling was not
> conditional on there being people in the vicinity.

Well, I can't speak for Canada, but here in Scotland there
is absolutely no need to signal unless there's other traffic
which might be affected by your manouver.

It's kind of like the tree in the quad.

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

IMHO, there aren't enough committed Christians, but
that's care in the community for you. -- Ben Evans

 

[Simon Brooke]

in message <[email protected]>, Elisa Francesca
Roselli ('[email protected]') wrote:

> Simon Brooke wrote:
>
>> Dynamic steering wobbles are usually caused by too much
>> lateral flexibility of the frame. They can be made worse
>> by weight forward of the steering pivot (e.g. a heavy bar
>> bag or bar-mounted basket). They are extremely dangerous
>> - as you have found - and on the whole if it can't be
>> traced to an unusual amount of weight forward of the
>> steering pivot I would be inclined not ot ride that bike
>> any more.
>
> Well, Behemoth does have a front basket, but there was
> nothing in it that afternoon, so it shouldn't have been
> especially heavy, and there was a heavy pannier on the
> rear rack.

Weight on the back won't make a lot of difference in this
situation (it could make it worse but that's quite
complicated dynamics). What can happen when you have
weight in your basket is that that weight can act as a
pendulum, accentuating any steering wobble you have. As
Steve points out, bent forks can be implicated in this
sort of problem. Has Behemoth ever been ridden hard into a
kerb, wall or vehicle?

> As for abandoning the bike, this has been open for
> discussion before. She's a beautiful Dutch bike bought
> only last November
>
ikkelbikes.com/images/bikes/bikes_groot/popup_groot/neerhem-
d.jpg).

Yup. This sort of frame design is the worst for axial flex,
and quite bad for lateral flex. On a conventional bike
frame the crossbar joins the top of the head tube with the
top of the seat tube helping to prevent both from flexing.
Behemoth doesn't have one. This is OK in Holland which is
mostly flat and where bikes like this are typically
pedalled slowly, but as speed increases so does the energy
in all parts of the system, and a bike which will trundle
happily along all day at eight miles per hour may
experience dynamic problems at sixteen.

> What could cause lateral flexibility of the frame? It's a
> sturdy, and very heavy, aluminium monotube. The steering
> has been odd from the beginning, but as I am a very
> inexperienced beginner I thought it might be me.

If you look at the design the main tube and seat tube join
at the bottom bracket and are braced by one short brace just
above it. This means there's a lot of unsupported length of
both tubes and it is this unsupported length which can flex.
Flex in itself isn't necessarily a bad thing, but if the
harmonic period of the flexion of the frame is similar to
the harmonic period of the steering they will tend to excite
one another, leading to the violent steering oscillation you
experienced.

Note, of course, that I haven't ridden the bike and that
this is just one possible explanation - but it's the one
which seems to me to best fit the symptoms you describe.

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

[ This .sig subject to change without notice
]

 

[Ben]

"Simon Brooke" <[email protected]> wrote in message
news:[email protected]...
> in message <[email protected]
> .rogers.com>, loki ('[email protected]') wrote: Well, I
> can't speak for Canada, but here in Scotland there is
> absolutely no need to signal unless there's other traffic
> which might be affected by your manouver.
>
> It's kind of like the tree in the quad.

The one I ran into while signalling even when there was no-
one around?

--
Ben

 

[Simon D]

"Simon Brooke" <[email protected]> wrote in message
news:[email protected]...
> in message <[email protected]>,
> Elisa Francesca Roselli ('Elisa.Francesca.Roselli@quadratec-
> software.com') wrote:
>
> > Simon Brooke wrote:
> >
> >> Dynamic steering wobbles are usually caused by too much
> >> lateral flexibility of the frame. They can be made
> >> worse by weight forward of the steering pivot (e.g. a
> >> heavy bar bag or bar-mounted basket). They are
> >> extremely dangerous - as you have found - and on the
> >> whole if it can't be traced to an unusual amount of
> >> weight forward of the steering pivot I would be
> >> inclined not ot ride that bike any more.
> >
> > Well, Behemoth does have a front basket, but there was
> > nothing in it that afternoon, so it shouldn't have been
> > especially heavy, and there was a heavy pannier on the
> > rear rack.
>
> Weight on the back won't make a lot of difference in this
> situation (it could make it worse but that's quite
> complicated dynamics). What can happen when you have
> weight in your basket is that that weight can act as a
> pendulum, accentuating any steering wobble you have. As
> Steve points out, bent forks can be implicated in this
> sort of problem. Has Behemoth ever been ridden hard into a
> kerb, wall or vehicle?
>
> > As for abandoning the bike, this has been open for
> > discussion before. She's a beautiful Dutch bike bought
> > only last November
> >
>
ikkelbikes.com/images/bikes/bikes_groot/popup_groot/neerhem-
d.j pg).
>
> Yup. This sort of frame design is the worst for axial
> flex, and quite bad for lateral flex. On a conventional
> bike frame the crossbar joins the top of the head tube
> with the top of the seat tube helping to prevent both from
> flexing. Behemoth doesn't have one. This is OK in Holland
> which is mostly flat and where bikes like this are
> typically pedalled slowly, but as speed increases so does
> the energy in all parts of the system, and a bike which
> will trundle happily along all day at eight miles per hour
> may experience dynamic problems at sixteen.
>
> > What could cause lateral flexibility of the frame? It's
> > a sturdy, and very heavy, aluminium monotube. The
> > steering has been odd from the beginning, but as I am a
> > very inexperienced beginner I thought it might be me.
>
> If you look at the design the main tube and seat tube join
> at the bottom bracket and are braced by one short brace
> just above it. This means there's a lot of unsupported
> length of both tubes and it is this unsupported length
> which can flex. Flex in itself isn't necessarily a bad
> thing, but if the harmonic period of the flexion of the
> frame is similar to the harmonic period of the steering
> they will tend to excite one another, leading to the
> violent steering oscillation you experienced.
>
> Note, of course, that I haven't ridden the bike and that
> this is just one possible explanation - but it's the one
> which seems to me to best fit the symptoms you describe.
>

I'd agree with everything Simon Brooke has written, and
would add that the forks seem to have a very short rake
(Simon has described this as "trail") which will definitely
make matters much worse. I think a pair of traditional forks
with longer rake could make a big difference.

---
Outgoing mail is certified Virus Free. Checked by AVG anti-
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Virus Database: 443 - Release Date: 10/05/2004

 

[Velvet]

Elisa Francesca Roselli wrote:

>
> JohnB wrote:
>
>
>>Firstly ride along in a straight line, take your hand from
>>the bars and just leave your arm hanging loose while you
>>ride while keeping eyes ahead. Usually this is very easy.
>
>
> It certainly isn't easy for me. I cannot remove my hands
> from the bars at all, not even for a fraction of a second,
> without veering off course. Same for trying to look behind
> me. In fact, steering on Behemoth is so reactive that,
> when I plan to turn a corner, it just suffices to look in
> the direction I plan to go and she's already off on it.
>
> EFR Ile de France
>

What strikes me immediately about that photo of your bike is
the lack of rake on the forks down by the wheel hub. I've
never ridden a bike with forks as straight as that, and it
looks like the actual axis of the wheel is just foward of
the fork, but even so, I'm wondering if that's the cause of
the twitchyness.

Others can probably advise better if the fork design is
likely to be the culprit or not.

--

Velvet

 

[Simon D]

"Velvet" <[email protected]> wrote in message
news:[email protected]...
> Elisa Francesca Roselli wrote:
>
> >
> > JohnB wrote:
> >
> >
> >>Firstly ride along in a straight line, take your hand
> >>from the bars and just leave your arm hanging loose
> >>while you ride while keeping eyes
ahead.
> >>Usually this is very easy.
> >
> >
> > It certainly isn't easy for me. I cannot remove my hands
> > from the bars
at all,
> > not even for a fraction of a second, without veering off
> > course. Same
for
> > trying to look behind me. In fact, steering on Behemoth
> > is so reactive
that,
> > when I plan to turn a corner, it just suffices to look
> > in the direction
I plan
> > to go and she's already off on it.
> >
> > EFR Ile de France
> >
>
> What strikes me immediately about that photo of your bike
> is the lack of rake on the forks down by the wheel hub.
> I've never ridden a bike with forks as straight as that,
> and it looks like the actual axis of the wheel is just
> foward of the fork, but even so, I'm wondering if that's
> the cause of the twitchyness.
>
> Others can probably advise better if the fork design is
> likely to be the culprit or not.
>

As I've mentioned in my post, I agree that the forks are
likely to be contributing, owing to lack of rake. However,
don't forget that they're suspension forks, Velvet, and have
some offset at the crown. There's not *quite* as little rake
as the picture at first suggests!

---
Outgoing mail is certified Virus Free. Checked by AVG anti-
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Virus Database: 443 - Release Date: 10/05/2004

 

[Just Zis Guy]

On Mon, 10 May 2004 17:31:14 +0200, Elisa Francesca Roselli
<[email protected]> wrote in message
<[email protected]>:

>kkelbikes.com/images/bikes/bikes_groot/popup_groot/neerhem-
>d.jpg).

Have you, perchance, raised the handlebars up on the
adjustable headset thingy?

Guy
--
May contain traces of irony. Contents liable to settle after posting.
http://www.chapmancentral.co.uk

88% of helmet statistics are made up, 65% of them at Washington University

 

[Velvet]

Simon D wrote:

>
>
> As I've mentioned in my post, I agree that the forks are
> likely to be contributing, owing to lack of rake. However,
> don't forget that they're suspension forks, Velvet, and
> have some offset at the crown. There's not *quite* as
> little rake as the picture at first suggests!
>

Ah, I didn't spot that they're suspension'd!

--

Velvet

 

[Ambrose Nankive]

In news:[email protected],
Elisa Francesca Roselli <[email protected]>
typed:
> Behemoth doesn't like this at all. Just after I _stop_
> nodding my head, she decides to convey this subtle
> movement to the whole of her frame, especially to her
> cranky, hypersensitive steering. And lo, the handlebars
> start wiggling right out of control, left, right, left,
> with barely enough space to compensate the imbalance
> because at the same time I'm trying to slow. I manage to
> stop her and very barely avoid an over-the-handlebars in
> moving traffic.

Presumably you weren't going particularly fast. I'd be quite
worried that there's a crack in a frame that really can't
take that kind of handling, otherwise I agree with everyone
elses posts. Presumably a crack around the headtube would be
the most likely place to cause this kind of problem.

A

 

[Claire Petersky]

"Roger Zoul" <[email protected]> wrote in message
news:[email protected]...
> Colin Petersky wrote:
> :: Claire Petersky wrote:
> ::
> ::: Please replace earthlink for mouse-potato and .net for
> ::: .com
> ::
> :: So it's you!
>
> Are you two related?

Generally Peterskys in North America are blood relatives,
descendents of my great-grandfather Simon Petersky (ne
Schmaje Pietezky) who emigrated to Canada in the early
1880s. However, there are Peterskys from central European
countries (no relation that I know of), some of whom have
emigrated elsewhere. I suspect Colin is one of these.
However, as someone with genealogy as a hobby, I'd be
interested to be proven wrong.

Warm Regards,

Claire Petersky Please replace earthlink for mouse-potato
and .net for .com Home of the meditative cyclist:
http://home.earthlink.net/~cpetersky/Welcome.htm See the
books I've set free at:
http://bookcrossing.com/referral/Cpetersky

 

[Bernie]

Elisa Francesca Roselli wrote:

>
>Colin Blackburn wrote:
>
>>Where are you posting from? This post is xposted to a
>>specifically UK group so opinions of traffic law are bound
>>to differ.
>>
>
>Sorry about the cross-posting. I enjoy the UK group because
>I'm often in the UK, generally find it easier to shop for
>cycling related stuff there and on UK based Web-sites than
>in Paris, and many of my cycling experiences and
>experiments specifically concern my favorite town of
>Cambridge.
>
>Behemoth and I, however, live and work in a suburb of
>Paris.
>
>EFR Ile de France
>
>
Do you still have your other bike? "Myrtille"? Changing
bikes now and then can add to your riding skills and give a
little insight into what's going on with the 'problem' bike.
In my experience, even similar bikes feel different.
Changing rides now and then can be an eye opener. Also, it
sounds like you ride in a lot of traffic congestion where
you commute. Perhaps a peaceful carless bike path will make
a difference in how you ride simply because it is easier to
relax. Best regards, Bernie

 

[Mark Tranchant]

JohnB wrote:

> Mark Tranchant wrote:
>
>>Colin Blackburn wrote:
>>
>>
>>>In the UK there are very few situations (if any?) where a
>>>motor vehicle is required to signal if there is no-one
>>>around who needs to know. Of course, many drivers fail to
>>>signal because they think peds and cyclists don't need to
>>>know but that's another matter.
>>
>
>
>>Whilst it is important that one is always aware of
>>everyone around, I think it's foolish to assume that
>>you've definitely seen everyone who might care about your
>>signal - what about the pedestrian behind the parked car,
>>for example?
>
>
>>This technique also encourages habitual correct
>>signalling, which can only be a good thing.
>
>
> A problem with *always* signalling and instilling it into
> training, especially with young people is that it can
> become more important than reading the road and the
> conditions. It is better to emphasise just why one needs
> to signal.

...which includes informing the person you haven't
(couldn't) see what you're doing.

> Of course signalling should always be carried out where it
> may affect someone else but to do it *****-nilly breeds a
> culture of "when I signal i have right of way" and one
> much practised by many motorists :-(

Agreed. Signalling should mean "I have determined that
now is a reasonable time to make the signalled action,
and I intend to manoeuvre accordingly as soon as it is
safe to do so".

Round these parts, it has a tendency to mean "here I come!".

> There are also situations where it can be positively
> dangerous for a cyclist to signal such as when turning
> left when there is a vehicle behind that is intending the
> same. A signal may encourage the vehicle to overtake just
> as the cyclist is also turning with disastrous and
> potentially fatal results.

True. I solve this (in all the left turns I need to make) by
moving out to prevent overtaking traffic and to give me a
better line through the corner.

--
Mark.

 

[Steve]

JohnB wrote:
> loki wrote:
>
>>"Roger Zoul" <[email protected]> wrote in message news:2g9c5nF4clhU1@uni-
>>berlin.de...
>>
>>>Elisa Francesca Roselli wrote:
>>>:: I'm no closer to being able to take my hands off the
>>>:: handlebars to signal direction than I was a year ago.
>>>
>>>Is that in general or in just the situation you describe
>>>below? Going downhill with some speed might make it
>>>difficult to signal a turn....
>>
>> That reminds of something I've been pondering in a 'Pinky
>> and The Brain' fashion:
>>
>>How long should one hold the signal?
>
>
> You should only need to signal if there is someone who
> needs to know, and to hold it until you are sure they have
> understood your intentions.
>
> John B

And if you don't see them...? I always signal, just in case,
'cos I aint infallable

Steve

 

[Just Zis Guy]

Claire Petersky wrote:

> Generally Peterskys in North America are blood relatives

And generally the "Colin Petersky" in question was an
amusing bit of sock-puppetry ;-)