Question:Anyone tried the new Timex Speed+Distance watch with the GPS transmitter? How
accurate are they? Any problem with signal loss while running?
Answer:
I've had mine about a week now. I want to do some more testing before I
make too many comments. So far it seems good. I want to see how some of
the miles on our recent race course check out. I'm interested in seeing if
it handles the hills. There are a couple of miles with about 500 feet of
climbing and decent in the middle. So far no reception problems but also no
woods or narrow canyons. I'll try to post again in a few weeks. The couple
of out and back courses I have run taking a split at the turn around have
only differed by a about .001-.003 mile between the out and back.
You're going to look a little silly with the GPS unit around your upper arm.
It's slightly larger but still seems to fit my wrist OK. I noticed it even
has a couple of holes left in the band here most of the standard Ironman
watches have at most one spare hole. My eyes are not the best (need cataract
surgery) so the top line of the display (the speed and distance part) can be
a little hard to read on the run. I generally don't really look at a watch
that much on a run but like to review things when I get home. I intend to
mainly measure some of my common courses and to help lay out some new routes
for myself. The 9-12 mile hill course I use to run is closed for two years
due to some manjor construction projects. I suspect I may also use it for
some trail runs that either don't allow bikes or are beyond my technical
ability to ride. It will be like my pulse monitor spmething that I don't
expect to wear on every run and don't really pay that much attention to on
the road but can review when I get home. I decided to get the speed/distance
rather than something like the fitsense in the hope that it will prove to be
more accurate on reporting distances. I don't see how the fitsense could stay
accurate for distance when my stride changes over a long hilly course.
I have a hard time believing the Fitsense could be more accurate than a GPS
based system....
I have the Triax, but the Fitsense uses the exact same technology, so it
should be the same. I find my unit accurate to under 5m per km on every
track session or sanctified, certified race I have run. I find it to remain at
this accuracy level at speeds between 3k race pace and LSD pace, and
at the corresponding distances. I've run tired slow 25k runs with dragging
feet, and 400m intervals in 75 seconds, both with the above-stated results.
However, I tried it when walking once, to see how it worked, and it was
off by almost 30m in 1km.
That's very impressive indeed. I've thought about getting one of these
things, but was only put off by the cost. I'm still tempted though. Do you
think it is as accurate on trails (dirt track / grass / mud)?
I don't know, I'd have to "certify" a segment of trail very carefully
with a proper wheel-type measuring device. I run on trails a few
times a month, but obviously nothing that I could tell you what
it was before I ran it.
I would imagine the accuracy would drop a bit... maybe to as
bad as 30 - 40m per km. Still... that's not too bad unless you are
doing a very long run; then it would add up after a while.
My handheld GPS (Garmin eTrex Vista) is usually showing a shorter
distance, as it cuts corners, and does not log if it loses track
of the satellites.
That said, if I can keep it locked on, my experience tells me that
it is usually 2-5% short. If You walk a straight line, it is way
better, but usually I do follow turning paths.
Using a good GPS (Garmin eTrex Vista), I find that the GPS is usually
2-5% short on most runs, even if I increase the sampling rate. So that
is what you are experiencing as well.
The good thing is, that if you use the GPS to set the distance, then you
will run faster at every race :)
Also realise the the gps is giving you a 2D (flat) distance and is not taking
into account vertical (hill) distance.
So true. That is why I won't even think about getting the Timex
SD(http://www.timex.com/spd). I mean a GPS that does not do altitude. I
have not seen anywhere that it is capable of it.
I looked at a GPS once and even the altitude on that thing would change
quite a bit, even if it was never moved. Heck, I think my Polar S710 does
better on Altitude than that particular GPS.
It would be pretty funny, if they put an altitude that did not work very
well on that watch and then people that would start freaking out. I mean,
I'm sure it would tell some people they were going down hill, when they were
in fact going up a steep hill. ;-)
If I do set it in normal mode (vs powersave), I will not normally
lose lock with the Vista, except in very bad conditions.
One thing I have found helps is to manually calibrate the altimeter
to a known altitude, as that will lower the satellite requirement
to maintain a lock with one satellite.
When I see it lose lock, it is usually in the woods, often when a hill
or something is blocking a few satellites. But it does guess your
movements, and thus will be able to track for a few seconds with no
lock before giving up.
The etrex line is most sensitive to satellites when held horizontally not
vertically.
I'll have to try these suggestions, as well as being sure to
keep it horizontal. Part of the problem with the first test may have
been the alkaline batteries the guy had put in there. I use lithium
batteries in mine to avoid droppage that alkalines have - and just be
sure I have spares for when they drain completely without warning. They
both have lithium now, and the eTrex has worked much better since
replacing batteries.
I did a mile on a track today out of curiosity to see how accurate my
Timex Sped+Distance is. It measured the mile as 1.008, so its pretty
close. I figure it is more accurate on a track because its a totally
flat surface and I'm moving in a consistent pattern. Anyone else have
thoughts on this?
I was finally able to get out to some the portion of our half marathon
course today (I'm taking the week off from work) and tested the watch out
over about 4 miles of the course that still had clear markings. This part
of the course includes a climv of about 250 feet in a litle over a half mile
then a dip of perhaps 80' and climb back of 50' over the next wauarter mile
and finally a drop of another 200-250 feet over the next mile. There are
perhaps a half dozeb broad curves and a number of sharp corners over the
four miles section I measured. I did the course twice with some side trips
on the second loup out for a total of just over 11 miles. On the measured
miles (including the ones with the hills) I was getting readings of +-0.005
mile. This is plenty accurate for me especially when I wasn't out there when
the course was certified and don't know the exact tangents that were used to
the course was certified and don't know what tangents may have been used. I
cut very few tangents today. At some point I hope to get out to some real
hills (8-14% grades) with known good mile markers to see if the accuracy
holds up.
On my second time up the big hill I switched the watch to display current
pace and got to watch how much fun it is to climb with 10 extra pounds.
I struggled to keep the pace at 12:30-13:00. The good thing is once I
crested the hill a sub 7:00 pace was easy going down.
