Timex Bodylink vs Garmin Forerunner - Triathlon Week

08-23-2004, 07:09 PM

I would appreciate any opinions from users of the Timex Bodylink or
the Garmin Forerunner GPS units. I would like something to measure
the distance travelled on streets so I can compare it to distances on
the track or treadmill.

Thanks,

Jim

08-23-2004, 07:09 PM

I read a review recently from a guy who has used both. Hopefully someone
else can point to the article.

The downside to the Timex to me is that it is 2 pieces, more costly and I
just do not like the idea of having something around my upper arm while I
run.

Got the Forerunner 201--no regrets so far.
"Jim" <[Only registered and activated users can see links. ]> wrote in message
news:[Only registered and activated users can see links. ]...
>
> I would appreciate any opinions from users of the Timex Bodylink or
> the Garmin Forerunner GPS units. I would like something to measure
> the distance travelled on streets so I can compare it to distances on
> the track or treadmill.
>
> Thanks,
>
> Jim

08-23-2004, 07:09 PM

"Mike Painter" <[Only registered and activated users can see links. ]> wrote in message
news:HwoAc.4428$[Only registered and activated users can see links. ].prodigy.com ...
>
> "Ironic" <[Only registered and activated users can see links. ]> wrote in message
> news:38f527b7.0406161928.4cc53107@posting.google.c om...
> > Jim <[Only registered and activated users can see links. ]> wrote in message
> news:<[Only registered and activated users can see links. ]>. ..
> > > I would appreciate any opinions from users of the Timex Bodylink or
> > > the Garmin Forerunner GPS units. I would like something to measure
> > > the distance travelled on streets so I can compare it to distances on
> > > the track or treadmill.
> > >
>
> I'm a bit suspect of GPS in this format for accurate measurement. Mine is
> consistently about .3 miles off in about a 3.8xx mile course as measured
> both by car and mapping software. The car was "calibrated" against two
miles
> of highway markers at the same speed the course was driven.
>
>

Are you sure highway markers are accurate?

Are you running the exact same path as the car is driving?

Could the mapping software be off? You are assuming it is 100% accurate.

08-23-2004, 07:09 PM

"Sam" <[Only registered and activated users can see links. ]> wrote in message
news:faOAc.5813$[Only registered and activated users can see links. ].pas.earthl ink.net...
>
> "Mike Painter" <[Only registered and activated users can see links. ]> wrote in message
> news:HwoAc.4428$[Only registered and activated users can see links. ].prodigy.com ...
> >
> > "Ironic" <[Only registered and activated users can see links. ]> wrote in message
> > news:38f527b7.0406161928.4cc53107@posting.google.c om...
> > > Jim <[Only registered and activated users can see links. ]> wrote in message
> > news:<[Only registered and activated users can see links. ]>. ..
> > > > I would appreciate any opinions from users of the Timex Bodylink or
> > > > the Garmin Forerunner GPS units. I would like something to measure
> > > > the distance travelled on streets so I can compare it to distances
on
> > > > the track or treadmill.
> > > >
> >
> > I'm a bit suspect of GPS in this format for accurate measurement. Mine
is
> > consistently about .3 miles off in about a 3.8xx mile course as measured
> > both by car and mapping software. The car was "calibrated" against two
> miles
> > of highway markers at the same speed the course was driven.
> >
> >
>
> Are you sure highway markers are accurate?
They are very accurate. A run of five or ten at 60 mph agree both in time
and odomotor reading.
>
> Are you running the exact same path as the car is driving?
>
For all practical purposes, yes, left hand turns are not as close to right
hand turns but there are are only four of them out of a total of eight. They
don't differ from what I walk by almost three tenths of a mile and the GPS
reports essentially the same distance walking or driving.

> Could the mapping software be off? You are assuming it is 100% accurate.
I am assuming it is not off by a large margin. It is almost certain that it
came from surveys, it also places addresses very close to the correct
location
>
The software agrees with several other brands, as well as with the mileage
markers.
When 2 out of 3 things agree, in the lack of other evidence, it is safe to
assume the third one is wrong.

08-23-2004, 07:09 PM

On 2004-06-19, Mike Painter <[Only registered and activated users can see links. ]> wrote:
>
>> > I'm a bit suspect of GPS in this format for accurate measurement. Mine
>> > is
>> > consistently about .3 miles off in about a 3.8xx mile course as measured
>> > both by car and mapping software. The car was "calibrated" against two
>> > miles of highway markers at the same speed the course was driven.
>>
>> Are you sure highway markers are accurate?
> They are very accurate. A run of five or ten at 60 mph agree both in time
> and odomotor reading.

Since the car was "calibrated" against the highway markers, you don't know that
the highway markers are accurate. If I calibrate X against Y, then Y will for the
most part agree with X.

>> Could the mapping software be off? You are assuming it is 100% accurate.
> I am assuming it is not off by a large margin. It is almost certain that it
> came from surveys, it also places addresses very close to the correct
> location
>>
> The software agrees with several other brands,

But there are relatively few sources of data for these software packages, so this
"agreement" could in fact amount to a single data source agreeing with itself.

> as well as with the mileage markers. When 2 out of 3 things agree, in the
> lack of other evidence, it is safe to assume the third one is wrong.

Only if you assume that all three pieces of evidence have equal weight. That is
not in general (or in this instance) a good assumption.

Cheers,
--
Donovan Rebbechi
[Only registered and activated users can see links. ]

08-23-2004, 07:09 PM

In article <Y8OAc.5811$[Only registered and activated users can see links. ].pas.earthlink. net>, Sam wrote:
> I read a review recently from a guy who has used both. Hopefully someone
> else can point to the article.

This one from me?
[Only registered and activated users can see links. ]

BTW the S625X is out, discussion here:
[Only registered and activated users can see links. ]

Paul

08-23-2004, 07:09 PM

"Donovan Rebbechi" <[Only registered and activated users can see links. ]> wrote in message
news:[Only registered and activated users can see links. ]...
> On 2004-06-19, Mike Painter <[Only registered and activated users can see links. ]> wrote:
> >
> >> > I'm a bit suspect of GPS in this format for accurate measurement.
Mine
> >> > is
> >> > consistently about .3 miles off in about a 3.8xx mile course as
measured
> >> > both by car and mapping software. The car was "calibrated" against
two
> >> > miles of highway markers at the same speed the course was driven.
> >>
> >> Are you sure highway markers are accurate?
> > They are very accurate. A run of five or ten at 60 mph agree both in
time
> > and odomotor reading.
>
> Since the car was "calibrated" against the highway markers, you don't know
that
> the highway markers are accurate. If I calibrate X against Y, then Y will
for the
> most part agree with X.

Don't be silly If I drive for x minutes at 60 miles per hour and my
odomoter says I have traveled x mile and the mileage markers say I have
covered x miles then I have traveled x miles. s = vt.

Even if there was any validity in your argument you are saying that all
highway mileage markers on all the roads I travel are off by the same amount
yet match my odomoter for almost any distance I measure.

>
> >> Could the mapping software be off? You are assuming it is 100%
accurate.
> > I am assuming it is not off by a large margin. It is almost certain that
it
> > came from surveys, it also places addresses very close to the correct
> > location
> >>
> > The software agrees with several other brands,
>
> But there are relatively few sources of data for these software packages,
so this
> "agreement" could in fact amount to a single data source agreeing with
itself.
>
> > as well as with the mileage markers. When 2 out of 3 things agree, in
the
> > lack of other evidence, it is safe to assume the third one is wrong.
>
> Only if you assume that all three pieces of evidence have equal weight.
That is
> not in general (or in this instance) a good assumption.
It is a very good assumption. I asume that $5,000.00 plus GPS systems that
are used in surveying are more accurate than $100.00 units with small
antennas.
I am certain that 60 mph is one mile in one minute and that my watch which
looses less than 15 seconds in six months is accurate and precise. Therefore
my odomoter which agrees with both time and markers is accurate
I am assuming that if my house and the house of my friend 10 miles away show
up on the map where they should then the map is accurate.

>
> Cheers,
> --
> Donovan Rebbechi
> [Only registered and activated users can see links. ]

08-23-2004, 07:09 PM

On 2004-06-19, Mike Painter <[Only registered and activated users can see links. ]> wrote:
>
> "Donovan Rebbechi" <[Only registered and activated users can see links. ]> wrote in message
> news:[Only registered and activated users can see links. ]...
>> On 2004-06-19, Mike Painter <[Only registered and activated users can see links. ]> wrote:
>> >
>> >> > I'm a bit suspect of GPS in this format for accurate measurement.
> Mine
>> >> > is
>> >> > consistently about .3 miles off in about a 3.8xx mile course as
> measured
>> >> > both by car and mapping software. The car was "calibrated" against
> two
>> >> > miles of highway markers at the same speed the course was driven.
>> >>
>> >> Are you sure highway markers are accurate?
>> > They are very accurate. A run of five or ten at 60 mph agree both in
> time
>> > and odomotor reading.
>>
>> Since the car was "calibrated" against the highway markers, you don't know
> that
>> the highway markers are accurate. If I calibrate X against Y, then Y will
> for the
>> most part agree with X.
>
> Don't be silly If I drive for x minutes at 60 miles per hour and my
> odomoter says I have traveled x mile and the mileage markers say I have
> covered x miles then I have traveled x miles. s = vt.
>
> Even if there was any validity in your argument you are saying that all
> highway mileage markers on all the roads I travel are off by the same amount
> yet match my odomoter for almost any distance I measure.

Part of the problem is that I wasn't actually clear on what you were saying
(you simply weren't very clear). If you find the odometer consistent across a
large number of highway markers in different locations, with different tire
pressures, then at least your odometer is accurate under those conditions. But
keep in mind that the accuracy of your odometer could be influenced by several
variables (corners, terrain, etc)

> It is a very good assumption. I asume that $5,000.00 plus GPS systems that
> are used in surveying are more accurate than $100.00 units with small
> antennas.

That may be the case, but it does not follow that popular maps can consistently
beat a small GPS unit. If you want to familiarise yourself with the accuracy
of popular mapping software, google some of the GPS units.

Cheers,
--
Donovan Rebbechi
[Only registered and activated users can see links. ]

08-23-2004, 07:09 PM

"Donovan Rebbechi" <[Only registered and activated users can see links. ]> wrote in message
news:[Only registered and activated users can see links. ]...
> On 2004-06-19, Mike Painter <[Only registered and activated users can see links. ]> wrote:
> >
> > "Donovan Rebbechi" <[Only registered and activated users can see links. ]> wrote in message
> > news:[Only registered and activated users can see links. ]...
> >> On 2004-06-19, Mike Painter <[Only registered and activated users can see links. ]> wrote:
> >> >
> >> >> > I'm a bit suspect of GPS in this format for accurate measurement.
> > Mine
> >> >> > is
> >> >> > consistently about .3 miles off in about a 3.8xx mile course as
> > measured
> >> >> > both by car and mapping software. The car was "calibrated" against
> > two
> >> >> > miles of highway markers at the same speed the course was driven.
> >> >>
> >> >> Are you sure highway markers are accurate?
> >> > They are very accurate. A run of five or ten at 60 mph agree both in
> > time
> >> > and odomotor reading.
> >>
> >> Since the car was "calibrated" against the highway markers, you don't
know
> > that
> >> the highway markers are accurate. If I calibrate X against Y, then Y
will
> > for the
> >> most part agree with X.
> >
> > Don't be silly If I drive for x minutes at 60 miles per hour and my
> > odomoter says I have traveled x mile and the mileage markers say I have
> > covered x miles then I have traveled x miles. s = vt.
> >
> > Even if there was any validity in your argument you are saying that all
> > highway mileage markers on all the roads I travel are off by the same
amount
> > yet match my odomoter for almost any distance I measure.
>
> Part of the problem is that I wasn't actually clear on what you were
saying
> (you simply weren't very clear). If you find the odometer consistent
across a
> large number of highway markers in different locations, with different
tire
> pressures, then at least your odometer is accurate under those conditions.
But
> keep in mind that the accuracy of your odometer could be influenced by
several
> variables (corners, terrain, etc)
"A run of five or ten at 60 mph agree both in time and odomotor reading."
seems pretty clear to me."

>
> > It is a very good assumption. I asume that $5,000.00 plus GPS systems
that
> > are used in surveying are more accurate than $100.00 units with small
> > antennas.
>
> That may be the case, but it does not follow that popular maps can
consistently
> beat a small GPS unit. If you want to familiarise yourself with the
accuracy
> of popular mapping software, google some of the GPS units.
Popular mapping software which is linked to a large antenna is very precise.
The same software on handhelds linked to laptops are not.
The same can be said of GPS units in Nextel phones used in commercial
systems.
They will show addresses and locations off by a considerable margin while
the same company using the same software with a decent antenna will be spot
on.

08-23-2004, 07:09 PM

Sam wrote:

> Are you sure highway markers are accurate?

On most highways, the mile markers are very accurate.
The sign locations are set by surveyors, according to the
plan. So they are normally accurate within about a
tenth of a foot.

The state wants to be sure that it gets _exactly_ the
amount of road that it orders and pays for. <g>

Of course, the road miles are surveyed down the centerline.
If you run/walk/bike some other path (such as the 'shortest'
path) then you could actually run less distance. But the
difference (for each time you cross from left-to-right or
right-to-left) would normally be much less than the width
of the road.

Steve

08-23-2004, 07:09 PM

On 2004-06-19, Mike Painter <[Only registered and activated users can see links. ]> wrote:
>

>> That may be the case, but it does not follow that popular maps can
> consistently
>> beat a small GPS unit. If you want to familiarise yourself with the
> accuracy
>> of popular mapping software, google some of the GPS units.
> Popular mapping software which is linked to a large antenna is very precise.
> The same software on handhelds linked to laptops are not.
> The same can be said of GPS units in Nextel phones used in commercial
> systems.
> They will show addresses and locations off by a considerable margin while
> the same company using the same software with a decent antenna will be spot
> on.

Not sure that I understand what you're saying. Mapping software can not be more
accurate than the maps themselves. The accuracy of the maps depends on the data
source. Maps based on Tiger data or USGS data are of variable quality (Tiger
data maps are especially flaky in places). There are other maps based on ETAK
data which are more accurate. The maps at places like maps.yahoo.com or
mapquest are among the better quality maps (I think these are from ETAK data.
They're from one of the better sources anyway)

Mapping software can estimate distance independently of the unit. The accuracy
of this measure depends on the accuracy of the map.

On the other hand, if one uses the GPS unit itself to measure the route, the
accuracy has everything to do with the accuracy of the GPS and how appropriate
the firmware is for measuring that sort of route, but has nothing to do with
the quality of the maps.

Cheers,
--
Donovan Rebbechi
[Only registered and activated users can see links. ]

08-23-2004, 07:09 PM

Ok. Lets stop for a while and get back to the main question!!!!
I have just received a Timex ironman GPS/HR unit I do not yet have the data
recorder!
I have also contracted a nasty flu virus for the last week so have not been
able to give it a real good pasting.
I did use it on 19/06 for a short time I know from my race results that I
can do 6 min mile duathlons. I liked the way the watch was able to display
my mile timings and they seemed quite exact to my race experience. The
distance updated quickly but in some industrial areas the timings did lag
then catch up, due I take to structures. The amount of information the unit
gives is excellent and I will be purchasing a data logger to graph on a PC.
I will be purchasing the data logger so I can compare against same routes
every couple of weeks with differing routines. (my units have new batteries
all round!!!!)

I see the body link system as an excellent method of data capture and
analysis. In about 3 weeks I should have detailed stats and could give
feedback from my experience good or bad, I will be using the units on a bike
which is my best discipline (cat 2/1).

Kent
The reason for the flu is me being a PRAT and doing an 80km enduro then next
day 3 mile run, next day 33 road race, then brick session, run, ( turbos in
a hot garage, cooldowns watering the garden) No rest. You must answer to
your body I did not and thus have lost 5 days of any exercise, listen, learn
and improve by the most important part part of any athelete your brain.

08-23-2004, 07:09 PM

"Kent" <[Only registered and activated users can see links. ].uk> wrote in message news:<cb54ki$5ag$[Only registered and activated users can see links. ].pol.co.uk>...
> Ok. Lets stop for a while and get back to the main question!!!!
> I have just received a Timex ironman GPS/HR unit I do not yet have the data
> recorder!
> I have also contracted a nasty flu virus for the last week so have not been
> able to give it a real good pasting.
> I did use it on 19/06 for a short time I know from my race results that I
> can do 6 min mile duathlons. I liked the way the watch was able to display
> my mile timings and they seemed quite exact to my race experience. The
> distance updated quickly but in some industrial areas the timings did lag
> then catch up, due I take to structures. The amount of information the unit
> gives is excellent and I will be purchasing a data logger to graph on a PC.
> I will be purchasing the data logger so I can compare against same routes
> every couple of weeks with differing routines. (my units have new batteries
> all round!!!!)
>
> I see the body link system as an excellent method of data capture and
> analysis. In about 3 weeks I should have detailed stats and could give
> feedback from my experience good or bad, I will be using the units on a bike
> which is my best discipline (cat 2/1).
>
> Kent
> The reason for the flu is me being a PRAT and doing an 80km enduro then next
> day 3 mile run, next day 33 road race, then brick session, run, ( turbos in
> a hot garage, cooldowns watering the garden) No rest. You must answer to
> your body I did not and thus have lost 5 days of any exercise, listen, learn
> and improve by the most important part part of any athelete your brain.

Does your GPS unit look like the one on the Timex website
[Only registered and activated users can see links. ] (made by Navman,
or is the older one made by Garmin for Timex? They look different.
Note that the website says "GPS Unit may look different from the one
shown in the picture".Timex got Navman to start making them in January
to address, accuracy, weight and battery life issues.

Greg

08-23-2004, 07:09 PM

>
> Does your GPS unit look like the one on the Timex website
> [Only registered and activated users can see links. ] (made by Navman,
> or is the older one made by Garmin for Timex? They look different.
> Note that the website says "GPS Unit may look different from the one
> shown in the picture".Timex got Navman to start making them in January
> to address, accuracy, weight and battery life issues.
>
> Greg

Yep that's the one.
I managed a short run today and noticed this annoying bit.
As you run along in a fairly straight line then suddenly turn (field edge
etc) the GPS suddenly gives a horrid split time and then plays catch up for
about 30 secs. I understand the reason for this and I have enabled the
smoothing functions to see if there is any difference.
I will do a fair length run and follow the route on my MTB and see if the
distances tally up.
I am also going out with the local road racers tomorrow night so will be
able to judge the distance/speed against the cycle computer.

Kent

08-23-2004, 07:09 PM

"Kent" <[Only registered and activated users can see links. ].uk> wrote in message news:<cb7bag$m47$[Only registered and activated users can see links. ].pol.co.uk>...
> >
> > Does your GPS unit look like the one on the Timex website
> > [Only registered and activated users can see links. ] (made by Navman,
> > or is the older one made by Garmin for Timex? They look different.
> > Note that the website says "GPS Unit may look different from the one
> > shown in the picture".Timex got Navman to start making them in January
> > to address, accuracy, weight and battery life issues.
> >
> > Greg
>
> Yep that's the one.
> I managed a short run today and noticed this annoying bit.
> As you run along in a fairly straight line then suddenly turn (field edge
> etc) the GPS suddenly gives a horrid split time and then plays catch up for
> about 30 secs. I understand the reason for this and I have enabled the
> smoothing functions to see if there is any difference.
> I will do a fair length run and follow the route on my MTB and see if the
> distances tally up.
> I am also going out with the local road racers tomorrow night so will be
> able to judge the distance/speed against the cycle computer.
>
> Kent

Kent--Get out the manual. There are a couple of "smoothing" options.
Read them and try them. It should fix that sudden corner turn thing.
By "horrid split time" do you mean a bad PACE. Speaking for myself,
when I got a good signal, it was very accurate in giving me
distances--but I generally know my distances, its the pace I wanted it
for (plus the HR info, splits, etc.). I expect to get the Navman unit
this week, and I will keep you posted.

Check "Speed and Pace Smoothing" on page 1-52 of the Manual. Also neat
is that it will take time and HR average splits for you at
pre-determined distances, e.g. every mile. It will also do some "beep"
signals, but my hearing isn't good enough to hear it. My loved ones do
not allow me to have anything that beeps, since I don't know it is
beeping. I figure, when it beeps, they can "Hey, your watch is
beeping", and that is just as good as far as I'm concerned, but they
don't see it that way.

Greg