hac4 computer loses heart rate on descents

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Recently purchased a HAC4.

I've been using it for a couple of weeks now and find that
on descents , the hear rate readings either jump around
wildly or just stay on zero.

The problem also seems to occur when riding fast on
the flats.

It is almost as if the receiving unit is unable to process
the data it is receiving quickly enough - from the wireless
transmitter on the fork and the heart rate monitor chest
strap . I have moved the fork-mounted transmitter as close
to the rim as possible to shorten the distance between bar-
mounted receiving unit and the trasmitter but this did not
seem to improve things.

The speed readings are also flakey when riding > 25 mph. I
do have another magnet and a wired speedo on my front wheel
(on the right side - the HAC4 is mounted on the left) - i
don't know if this could be an issue.

When riding at moderate speeds , Heart Rate and speed data
seemes reliable.

I haven't yet tried changing batteries of cleaning contacts
- odd that it is only when going fast that this is an issue.

Any help appreciated

Andrew Smit wrote:

> Recently purchased a HAC4.
>
> I've been using it for a couple of weeks now and find that
> on descents , the hear rate readings either jump around
> wildly or just stay on zero.
>
> The problem also seems to occur when riding fast on
> the flats.

I have a Polar 720, not a HAC4. But I see the same problem
on descents, which for me is caused by the chest transmitter
contacts drying out. I now use electrode cream on the
contacts, which almost always prevents this problem from
happenning:

http://froogle.google.com/froogle?q=signa%20cream

--
terry morse Palo Alto, CA http://bike.terrymorse.com/

Terry Morse wrote:
> Andrew Smit wrote:
>
>
>>Recently purchased a HAC4.
>>
>>I've been using it for a couple of weeks now and find that
>>on descents , the hear rate readings either jump around
>>wildly or just stay on zero.
>>
>>The problem also seems to occur when riding fast on
>>the flats.
>
>
> I have a Polar 720, not a HAC4. But I see the same problem
> on descents, which for me is caused by the chest
> transmitter contacts drying out. I now use electrode cream
> on the contacts, which almost always prevents this problem
> from happenning:
>
> http://froogle.google.com/froogle?q=signa%20cream
>
> --
> terry morse Palo Alto, CA http://bike.terrymorse.com/

I have a Polar A5 (fairly basic model, no coded transmitter)
and on descents, fast flats or strong wind it shows the same
problem: 0 or 200+ bpm. It's annoying, I never thought it
could be the contacts drying out but it seems logic. I'll
try next time!

On 28 Jun 2004 13:54:40 -0700, thismustbeavailable@yahoo.com (Andrew
Smit) wrote:

>Recently purchased a HAC4.
>
>I've been using it for a couple of weeks now and find that
>on descents , the hear rate readings either jump around
>wildly or just stay on zero.
>
>The problem also seems to occur when riding fast on
>the flats.
>
>It is almost as if the receiving unit is unable to process
>the data it is receiving quickly enough - from the wireless
>transmitter on the fork and the heart rate monitor chest
>strap . I have moved the fork-mounted transmitter as close
>to the rim as possible to shorten the distance between bar-
>mounted receiving unit and the trasmitter but this did not
>seem to improve things.
>
>The speed readings are also flakey when riding > 25 mph. I
>do have another magnet and a wired speedo on my front wheel
>(on the right side - the HAC4 is mounted on the left) - i
>don't know if this could be an issue.
>
>When riding at moderate speeds , Heart Rate and speed data
>seemes reliable.
>
>I haven't yet tried changing batteries of cleaning
>contacts - odd that it is only when going fast that this
>is an issue.
>
>Any help appreciated

At Cybex, we found that a person running on a treadmill over
6 to 7 mph could not have his heartrate reliable measured by
contact due to muscle noise. We did not find that to be true
on the chest strap system. I wonder if the dynamics of
biking create more muscle noise than running and its
interfereing with the pickup system. Hmmm

Michael J. Klein mklein@mousepotato.com Dasi Jen, Taoyuan
Hsien, Taiwan, ROC Please replace mousepotato with
asiancastings
---------------------------------------------

While out riding this weekend, I spoke to a guy who also had
a HAC4 but didn't report any heart rate reading issues on
descents. He did say he used the electrode gel.

I'll give the gel a try too although since my problem is so
quick to occur on a descent, I can't believe the sweat from
the transmitter has time to dry out and then start working
again as soon as I hit the flats.

I have replaced all the batteries (except the chest
transmitter since the unrelaible HR readings are also a
problem when I use a polar chest transmitter ) - I'll see if
that fixes the problem first.

If those things don't work, I'll experiment removing the
other wheel magnet (not sure if that is somehow effecting
things), riding without cell phone/blacberry (?) and riding
with the HAC4 strapped to the handlebar but not mounted on
the receiving unit.

Francesco Devittori <frenkatfrenkdtcm> wrote in message
news:<40e09acf$1@epflnews.epfl.ch>...
> Terry Morse wrote:
> > Andrew Smit wrote:
> >
> >
> >>Recently purchased a HAC4.
> >>
> >>I've been using it for a couple of weeks now and find
> >>that on descents , the hear rate readings either jump
> >>around wildly or just stay on zero.
> >>
> >>The problem also seems to occur when riding fast on the
> >>flats.
> >
> >
> > I have a Polar 720, not a HAC4. But I see the same
> > problem on descents, which for me is caused by the chest
> > transmitter contacts drying out. I now use electrode
> > cream on the contacts, which almost always prevents this
> > problem from happenning:
> >
> > http://froogle.google.com/froogle?q=signa%20cream
> >
> > --
> > terry morse Palo Alto, CA http://bike.terrymorse.com/
>
> I have a Polar A5 (fairly basic model, no coded
> transmitter) and on descents, fast flats or strong wind it
> shows the same problem: 0 or 200+ bpm. It's annoying, I
> never thought it could be the contacts drying out but it
> seems logic. I'll try next time!