bizarre behavior of cycling computer

may have said:

I have a cheap cycling computer I got at Performance ("dB 4LW
Wireless"😉. Sometimes, when the bike is not moving, I see the computer
showing speeds over 70 mph. This does not happen when I am riding.
Obviosuly, this behavior causes over-estimation of my travel distance,
and it also screws up my max speed reading (I've never gone above ~55
mph, sorry). I've seen this behavior with 3 computers of this
particular type. Does anyone know why this happens?

There's EMF being generated by something in the vicinity, and the comp
is reading that as a signal from the sender. Cell phones are among
the devices that are notorious for causing this.

--
My email address is antispammed; pull WEEDS if replying via e-mail.
Typoes are not a bug, they're a feature.
Words processed in a facility that contains nuts.

Quoted message said:

There's EMF being generated by something in the vicinity, and the comp
is reading that as a signal from the sender. Cell phones are among
the devices that are notorious for causing this.

Do all wireless computers (inlcuding high-end ones) have this problem?

may have said:

Quoted message said:

There's EMF being generated by something in the vicinity, and the comp
is reading that as a signal from the sender. Cell phones are among
the devices that are notorious for causing this.

Do all wireless computers (inlcuding high-end ones) have this problem?

Any wireless comp can have problems due to strong EMF and RFI in the
immediate vicinity. The degree to which they are able to cope with
and ignore these signals will vary, but I have yet to hear of one
that's completely immune to the problem. I haven't heard anything
that makes me think that the high-end units are remarkably better at
rejecting spurious signals than the best of the cheaper ones.

--
My email address is antispammed; pull WEEDS if replying via e-mail.
Typoes are not a bug, they're a feature.
Words processed in a facility that contains nuts.

<[email hidden]> wrote in message
news:[email hidden]
::: There's EMF being generated by something in the
::: vicinity, and the comp is reading that as a signal from
::: the sender. Cell phones are among the devices that are
::: notorious for causing this.
::
:: Do all wireless computers (inlcuding high-end ones) have
:: this problem?

No. If that's even a problem, it should not happen on a frequent basis if
you're out in the open.

Where has this happened for you? Under a power line, in a car?

"Werehatrack" <[email hidden]> wrote in message
news:[email hidden]
:: On 11 Dec 2006 22:29:28 -0800, [email hidden]
:: may have said:
::
:::
:::: There's EMF being generated by something in the
:::: vicinity, and the comp is reading that as a signal
:::: from the sender. Cell phones are among the devices
:::: that are notorious for causing this.
:::
::: Do all wireless computers (inlcuding high-end ones)
::: have this problem?
::
:: Any wireless comp can have problems due to strong EMF
:: and RFI in the immediate vicinity.

There aren't going to be many sources of EMF as strong as his moving
magnetic. If the pickup is that sensitive, then it's just wacked.

The degree to which
:: they are able to cope with and ignore these signals will
:: vary, but I have yet to hear of one that's completely
:: immune to the problem. I haven't heard anything that
:: makes me think that the high-end units are remarkably
:: better at rejecting spurious signals than the best of
:: the cheaper ones.

Come on...he's not even moving and the computer is reading 70 mph. It's
more likely that the machine is just foobarred than he's constantly exposed
to such strong EMFs, unless he's just carrying a source with him or
something.

::
:: --
:: My email address is antispammed; pull WEEDS if replying
:: via e-mail. Typoes are not a bug, they're a feature.
:: Words processed in a facility that contains nuts.

Quoted message said:

I have a cheap cycling computer I got at Performance ("dB 4LW
Wireless"😉. Sometimes, when the bike is not moving, I see the computer
showing speeds over 70 mph. This does not happen when I am riding.
Obviosuly, this behavior causes over-estimation of my travel distance,
and it also screws up my max speed reading (I've never gone above ~55
mph, sorry). I've seen this behavior with 3 computers of this
particular type. Does anyone know why this happens?

---------------
I have a new cateye micro wireless that gets it's max speed wacked
almost always, when I'm riding in town. All the rest of the readings
are ok, just the max speed shows some ridiculous high speed. Now when
I get out of town and ride in the boondocks it never happens.

On my other bike I have an old specialized wireless, and it's high
speed never gets wacked, ridden on the same routes, that wack the other
one.

I don't think there is a way to fix it, but the high speed reading
isn't that important, it's just irritating that it isn't correct.

"Crescentius Vespasianus" <[email hidden]> wrote in
message
news:[email hidden]
:: [email hidden] wrote:
::: I have a cheap cycling computer I got at Performance
::: ("dB 4LW Wireless"😉. Sometimes, when the bike is not
::: moving, I see the computer showing speeds over 70 mph.
::: This does not happen when I am riding. Obviosuly, this
::: behavior causes over-estimation of my travel distance,
::: and it also screws up my max speed reading (I've never
::: gone above ~55 mph, sorry). I've seen this behavior
::: with 3 computers of this particular type. Does anyone
::: know why this happens?
:: ---------------
:: I have a new cateye micro wireless that gets it's max
:: speed wacked almost always, when I'm riding in town.
:: All the rest of the readings are ok, just the max speed
:: shows some ridiculous high speed. Now when I get out of
:: town and ride in the boondocks it never happens.

Have you tried relocating the computer/transmitter?

::
:: On my other bike I have an old specialized wireless, and
:: it's high speed never gets wacked, ridden on the same
:: routes, that wack the other one.
::
:: I don't think there is a way to fix it, but the high
:: speed reading isn't that important, it's just irritating
:: that it isn't correct.

It might be correct even if it seems believable! 🙂

On Tue, 12 Dec 2006 06:15:17 -0500, "Roger Zoul"

may have said:

"Werehatrack" <[email hidden]> wrote in message
news:[email hidden]
:: On 11 Dec 2006 22:29:28 -0800, [email hidden]
:: may have said:
::
:::
:::: There's EMF being generated by something in the
:::: vicinity, and the comp is reading that as a signal
:::: from the sender. Cell phones are among the devices
:::: that are notorious for causing this.
:::
::: Do all wireless computers (inlcuding high-end ones)
::: have this problem?
::
:: Any wireless comp can have problems due to strong EMF
:: and RFI in the immediate vicinity.

There aren't going to be many sources of EMF as strong as his moving
magnetic. If the pickup is that sensitive, then it's just wacked.

The degree to which
:: they are able to cope with and ignore these signals will
:: vary, but I have yet to hear of one that's completely
:: immune to the problem. I haven't heard anything that
:: makes me think that the high-end units are remarkably
:: better at rejecting spurious signals than the best of
:: the cheaper ones.

Come on...he's not even moving and the computer is reading 70 mph. It's
more likely that the machine is just foobarred than he's constantly exposed
to such strong EMFs, unless he's just carrying a source with him or
something.

It's a wireless unit. Many of these units' heads will directly read
local EMF (and often RFI) as a signal from the sender. When a
wireless comp is indicating fantasy speeds and distances, it isn't
necessarily the sensor picking up stray EMF as a magnet pass, it's
been verified that it can be the comp head's receiver directly reading
the signal from the air. That's been seen in cases where the spurious
reading happens when the sender is many blocks or miles away from the
head. I have seen or been told of this with various brands of
wireless comp, and that's a good bit of the reason that I use a wired
unit.

It appears that since there's no security issue involved, the wireless
comp circuit designers are not putting in any significant amount of
hardware to insure that unwanted signals are rejected.

--
My email address is antispammed; pull WEEDS if replying via e-mail.
Typoes are not a bug, they're a feature.
Words processed in a facility that contains nuts.

"Werehatrack" <[email hidden]> wrote in message
news:[email hidden]
:: On Tue, 12 Dec 2006 06:15:17 -0500, "Roger Zoul"
:: <[email hidden]> may have said:
::
::: "Werehatrack" <[email hidden]> wrote in
::: message news:[email hidden]
::::: On 11 Dec 2006 22:29:28 -0800, [email hidden]
::::: may have said:
:::::
::::::
::::::: There's EMF being generated by something in the
::::::: vicinity, and the comp is reading that as a signal
::::::: from the sender. Cell phones are among the devices
::::::: that are notorious for causing this.
::::::
:::::: Do all wireless computers (inlcuding high-end ones)
:::::: have this problem?
:::::
::::: Any wireless comp can have problems due to strong EMF
::::: and RFI in the immediate vicinity.
:::
::: There aren't going to be many sources of EMF as strong
::: as his moving magnetic. If the pickup is that
::: sensitive, then it's just wacked.
:::
:::
::: The degree to which
::::: they are able to cope with and ignore these signals
::::: will vary, but I have yet to hear of one that's
::::: completely immune to the problem. I haven't heard
::::: anything that makes me think that the high-end units
::::: are remarkably better at rejecting spurious signals
::::: than the best of the cheaper ones.
:::
::: Come on...he's not even moving and the computer is
::: reading 70 mph. It's more likely that the machine is
::: just foobarred than he's constantly exposed to such
::: strong EMFs, unless he's just carrying a source with
::: him or something.
::
:: It's a wireless unit. Many of these units' heads will
:: directly read local EMF (and often RFI) as a signal from
:: the sender. When a wireless comp is indicating fantasy
:: speeds and distances, it isn't necessarily the sensor
:: picking up stray EMF as a magnet pass, it's been
:: verified that it can be the comp head's receiver
:: directly reading the signal from the air. That's been
:: seen in cases where the spurious reading happens when
:: the sender is many blocks or miles away from the head.
:: I have seen or been told of this with various brands of
:: wireless comp, and that's a good bit of the reason that
:: I use a wired unit.
::
:: It appears that since there's no security issue
:: involved, the wireless comp circuit designers are not
:: putting in any significant amount of hardware to insure
:: that unwanted signals are rejected.
::

I certainly do agree that this is indeed possible and I think it is likely
that it happens - sometimes. However, I do think it can be the result of
either a faulty unit or a cheap one. Just because it's wireless doesn't
mean that it has to be able to pick up just any random signals (such as when
you're not even moving). It's not that hard to code a transmitter with a
head unit of a certain brand so that there is some degree of isolation from
random signals even though the other info could receive interference.

Quoted message said:

I don't recall any posts about wired cyclocomputers giving
absurdly high readings.

Your memory is undoubtedly far superior to mine Carl, but back
in March 2004 I wrote in this NG:

"I came home from my morning ride and found that my bike
computer (a VDO C10 - wired, not wireless) had registered a max
speed of exactly 369.00 kph (the C10 reads to 2 decimal
places). Normally, I see a figure in the 40's or 50's.

I got to wondering about the cause, and thought that I might
have ridden close to a strong AC magnetic field at mains
frequency. Since the Australian mains frequency is 50 Hertz,
this could have switched the fork-mounted pickup at either 50
or 100 times per second (depending on whether both half-cycles
did the switching, or only one - an AC electromagnet reverses
polarity with each half-cycle). Given that the computer is
configured for a wheel circumference of 2050 mm, that gives me
a switching frequency of 50 Hertz exactly (to 3 decimal places)
for 369 kph."

John

<[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

I have a cheap cycling computer I got at Performance ("dB 4LW
Wireless"😉. Sometimes, when the bike is not moving, I see the computer
showing speeds over 70 mph. This does not happen when I am riding.
Obviosuly, this behavior causes over-estimation of my travel distance,
and it also screws up my max speed reading (I've never gone above ~55
mph, sorry). I've seen this behavior with 3 computers of this
particular type. Does anyone know why this happens?

H.I.D. lights cause my Polar to go crazy. My bar mounted Light & Motion Arc
light sits near the polar receiver wrist mount. Light goes on, speedo goes
bonkers.

Jeffrey

I said:

Your memory is undoubtedly far superior to mine Carl, but back
in March 2004 I wrote in this NG:

Sorry if that sounds critical. It wasn't meant to. At nearly
60, I can plead old-age for my many failings of memory.

John

"John Henderson" <[email hidden]> wrote in
message news:[email hidden]
:: [email hidden] wrote:
::
::: I don't recall any posts about wired cyclocomputers
::: giving absurdly high readings.
::
:: Your memory is undoubtedly far superior to mine Carl,
:: but back in March 2004 I wrote in this NG:
::
:: "I came home from my morning ride and found that my bike
:: computer (a VDO C10 - wired, not wireless) had
:: registered a max speed of exactly 369.00 kph (the C10
:: reads to 2 decimal places). Normally, I see a figure in
:: the 40's or 50's.
::
:: I got to wondering about the cause, and thought that I
:: might have ridden close to a strong AC magnetic field at
:: mains frequency. Since the Australian mains frequency
:: is 50 Hertz, this could have switched the fork-mounted
:: pickup at either 50 or 100 times per second (depending
:: on whether both half-cycles did the switching, or only
:: one - an AC electromagnet reverses polarity with each
:: half-cycle). Given that the computer is configured for
:: a wheel circumference of 2050 mm, that gives me a
:: switching frequency of 50 Hertz exactly (to 3 decimal
:: places) for 369 kph."
::

When you think about, these wired computers are probably not that well
shielded and induced signals along cable runs is quite possible.

:: John

John Henderson said:

Quoted message said:

I don't recall any posts about wired cyclocomputers giving
absurdly high readings.

Your memory is undoubtedly far superior to mine Carl, but back
in March 2004 I wrote in this NG:

"I came home from my morning ride and found that my bike
computer (a VDO C10 - wired, not wireless) had registered a max
speed of exactly 369.00 kph (the C10 reads to 2 decimal
places). Normally, I see a figure in the 40's or 50's.

I got to wondering about the cause, and thought that I might
have ridden close to a strong AC magnetic field at mains
frequency. Since the Australian mains frequency is 50 Hertz,
this could have switched the fork-mounted pickup at either 50
or 100 times per second (depending on whether both half-cycles
did the switching, or only one - an AC electromagnet reverses
polarity with each half-cycle). Given that the computer is
configured for a wheel circumference of 2050 mm, that gives me
a switching frequency of 50 Hertz exactly (to 3 decimal places)
for 369 kph."

John

Dear John,

Your memory is excellent--I simply forgot your posts.

Your theory is plausible, but I attribute your problem to
cyclocomputers being designed to work right-side up in the northern
hemisphere.

In Australia, of course, they are upside-down like everything else, so
occasionally all the impulses in the pickup fall down the wire and
into the computer in a sudden avalanche.

If I had a pacemaker, I'd be cautious of following you on your morning
ride, lest it shift my heartbeat to hummingbird mode.

Cheers,

Carl Fogel

Quoted message said:

Quoted message said:

I have a cheap cycling computer I got at Performance ("dB 4LW
Wireless"😉. Sometimes, when the bike is not moving, I see the
computer showing speeds over 70 mph. This does not happen when I am
riding. Obviosuly, this behavior causes over-estimation of my travel
distance, and it also screws up my max speed reading (I've never
gone above ~55 mph, sorry). I've seen this behavior with 3 computers
of this particular type. Does anyone know why this happens?

Dear R.,

As Werehatrack points out, stray signals tirggering the unit are by
far the most likely explanation.

I'm not so sure.

Quoted message said:

Posts about wireless cyclocomputers giving absurdly high readings are
common on RBT.

Some posters can even identify a spot on a daily route where the
wireless unit goes insane.

I don't recall any posts about wired cyclocomputers giving absurdly
high readings.

Wired computers giving double-speed readings is not uncommon when the sensor
is too near the magnet and switches twice per wheel revolution. If it's
just on brink of being OK, it may be fine for most revolutions but not for
some others. I've experienced this several times with Cateye Mity 3s.

I guess the same can happen with wireless as well (in addition to all the
other problems).

Quoted message said:

Perhaps the problem would be solved if wired units came with the wire
colored to match the fork? 🙂

The idea of wireless computers looking neater is funny when the sensors are
so large and chunky. They have to be mounted high on the forks as well,
making them even more promenent.

~PB

John Henderson said:

I said:

Your memory is undoubtedly far superior to mine Carl, but back
in March 2004 I wrote in this NG:

Sorry if that sounds critical. It wasn't meant to. At nearly
60, I can plead old-age for my many failings of memory.

John

Dear John,

Bah! No apologies needed. I've forgotten more than--

Than--

Er, let me get back to you on that.

Cheers,

Carl Fogel

Roger Zoul said:

"Werehatrack" <[email hidden]> wrote in message
news:[email hidden]
:: On Tue, 12 Dec 2006 06:15:17 -0500, "Roger Zoul"
:: <[email hidden]> may have said:
::
::: "Werehatrack" <[email hidden]> wrote in
::: message news:[email hidden]
::::: On 11 Dec 2006 22:29:28 -0800, [email hidden]
::::: may have said:
:::::
::::::
::::::: There's EMF being generated by something in the
::::::: vicinity, and the comp is reading that as a signal
::::::: from the sender. Cell phones are among the devices
::::::: that are notorious for causing this.
::::::
:::::: Do all wireless computers (inlcuding high-end ones)
:::::: have this problem?
:::::
::::: Any wireless comp can have problems due to strong EMF
::::: and RFI in the immediate vicinity.
:::
::: There aren't going to be many sources of EMF as strong
::: as his moving magnetic. If the pickup is that
::: sensitive, then it's just wacked.
:::
:::
::: The degree to which
::::: they are able to cope with and ignore these signals
::::: will vary, but I have yet to hear of one that's
::::: completely immune to the problem. I haven't heard
::::: anything that makes me think that the high-end units
::::: are remarkably better at rejecting spurious signals
::::: than the best of the cheaper ones.
:::
::: Come on...he's not even moving and the computer is
::: reading 70 mph. It's more likely that the machine is
::: just foobarred than he's constantly exposed to such
::: strong EMFs, unless he's just carrying a source with
::: him or something.
::
:: It's a wireless unit. Many of these units' heads will
:: directly read local EMF (and often RFI) as a signal from
:: the sender. When a wireless comp is indicating fantasy
:: speeds and distances, it isn't necessarily the sensor
:: picking up stray EMF as a magnet pass, it's been
:: verified that it can be the comp head's receiver
:: directly reading the signal from the air. That's been
:: seen in cases where the spurious reading happens when
:: the sender is many blocks or miles away from the head.
:: I have seen or been told of this with various brands of
:: wireless comp, and that's a good bit of the reason that
:: I use a wired unit.
::
:: It appears that since there's no security issue
:: involved, the wireless comp circuit designers are not
:: putting in any significant amount of hardware to insure
:: that unwanted signals are rejected.
::

I certainly do agree that this is indeed possible and I think it is likely
that it happens - sometimes. However, I do think it can be the result of
either a faulty unit or a cheap one. Just because it's wireless doesn't
mean that it has to be able to pick up just any random signals (such as
when
you're not even moving). It's not that hard to code a transmitter with a
head unit of a certain brand so that there is some degree of isolation
from random signals even though the other info could receive interference.

FWIW, My Specialized wireless cycle computer always shows crazy speeds when
I take it on electric trains, even when I'm a few cars away from the bike.

"Jim Higson" <[email hidden]> wrote in message
news:[email hidden]
:: Roger Zoul wrote:
::
::: "Werehatrack" <[email hidden]> wrote in
::: message news:[email hidden]
::::: On Tue, 12 Dec 2006 06:15:17 -0500, "Roger Zoul"
::::: <[email hidden]> may have said:
:::::
:::::: "Werehatrack" <[email hidden]> wrote in
:::::: message
:::::: news:[email hidden]
:::::::: On 11 Dec 2006 22:29:28 -0800,
:::::::: [email hidden] may have said:
::::::::
:::::::::
:::::::::: There's EMF being generated by something in the
:::::::::: vicinity, and the comp is reading that as a
:::::::::: signal from the sender. Cell phones are among
:::::::::: the devices that are notorious for causing this.
:::::::::
::::::::: Do all wireless computers (inlcuding high-end
::::::::: ones) have this problem?
::::::::
:::::::: Any wireless comp can have problems due to strong
:::::::: EMF and RFI in the immediate vicinity.
::::::
:::::: There aren't going to be many sources of EMF as
:::::: strong as his moving magnetic. If the pickup is that
:::::: sensitive, then it's just wacked.
::::::
::::::
:::::: The degree to which
:::::::: they are able to cope with and ignore these signals
:::::::: will vary, but I have yet to hear of one that's
:::::::: completely immune to the problem. I haven't heard
:::::::: anything that makes me think that the high-end
:::::::: units are remarkably better at rejecting spurious
:::::::: signals than the best of the cheaper ones.
::::::
:::::: Come on...he's not even moving and the computer is
:::::: reading 70 mph. It's more likely that the machine is
:::::: just foobarred than he's constantly exposed to such
:::::: strong EMFs, unless he's just carrying a source with
:::::: him or something.
:::::
::::: It's a wireless unit. Many of these units' heads will
::::: directly read local EMF (and often RFI) as a signal
::::: from the sender. When a wireless comp is indicating
::::: fantasy speeds and distances, it isn't necessarily
::::: the sensor picking up stray EMF as a magnet pass,
::::: it's been verified that it can be the comp head's
::::: receiver directly reading the signal from the air.
::::: That's been seen in cases where the spurious reading
::::: happens when the sender is many blocks or miles away
::::: from the head. I have seen or been told of this with
::::: various brands of wireless comp, and that's a good
::::: bit of the reason that I use a wired unit.
:::::
::::: It appears that since there's no security issue
::::: involved, the wireless comp circuit designers are not
::::: putting in any significant amount of hardware to
::::: insure that unwanted signals are rejected.
:::::
:::
::: I certainly do agree that this is indeed possible and I
::: think it is likely that it happens - sometimes.
::: However, I do think it can be the result of either a
::: faulty unit or a cheap one. Just because it's wireless
::: doesn't mean that it has to be able to pick up just any
::: random signals (such as when
::: you're not even moving). It's not that hard to code a
::: transmitter with a head unit of a certain brand so that
::: there is some degree of isolation from random signals
::: even though the other info could receive interference.
::
:: FWIW, My Specialized wireless cycle computer always
:: shows crazy speeds when I take it on electric trains,
:: even when I'm a few cars away from the bike.

Electric trains - are those the ones with the huge electric currents running
underneath? 🙂

Some LED lights will do this.

Quoted message said:

I have a cheap cycling computer I got at Performance ("dB 4LW
Wireless"😉. Sometimes, when the bike is not moving, I see the computer
showing speeds over 70 mph. This does not happen when I am riding.
Obviosuly, this behavior causes over-estimation of my travel distance,
and it also screws up my max speed reading (I've never gone above ~55
mph, sorry). I've seen this behavior with 3 computers of this
particular type. Does anyone know why this happens?