Altimeters - Blackburn vs. Cat Eye, any thoughts?



S

shawnews

Guest
I work in a bike shop and there are two bike computers with altitude
tracking available from our suppliers, the Blackburn Delphi 6.0 and the Cat
Eye CC-AT100 Altimeter.

It's hard to know from bullet points in a catalogue which is better,
obviously. The Cat Eye also does temperature and claims that its altitude
tracking is more accurate because it adjusts for temperature. The Delphi
6.0 is also a heart rate monitor so if their altitude functions are equal
then I'll go with it, but if the Cat Eye truly is a better altimeter then
I'd get a separate HR monitor.

Does anyone know anything about these altimeters, or have any experience
with them, that would be of value to me. Thanks in advance. :)
 
J

john

Guest
shawnews wrote:

>I work in a bike shop and there are two bike computers with altitude
>tracking available from our suppliers, the Blackburn Delphi 6.0 and the Cat
>Eye CC-AT100 Altimeter.


> It's hard to know from bullet points in a catalogue which is better,
>obviously. The Cat Eye also does temperature and claims that its altitude
>tracking is more accurate because it adjusts for temperature.


-snip-

An altimeter w/o temp. comp. is next to useless, in my experience. I
have observed as much as a 400-foot variation caused by temp. changes.
I would go w/ the Cat Eye, & get HR info elsewhere. Or consider a Polar
or other brand that gives both. Some Polars have temp. compensated
altimeters. I'm not sure they all do. If your shop is a QBP shop, I
believe they carry Polar. Polar is a very fine company w/ great
customer service.

Hope this helps, John
 
H

Hans

Guest
"shawnews" <[email protected]> schreef in bericht
news:IX7Nf.82718$H%[email protected]
> I work in a bike shop and there are two bike computers with altitude
> tracking available from our suppliers, the Blackburn Delphi 6.0 and the

Cat
> Eye CC-AT100 Altimeter.
>
> It's hard to know from bullet points in a catalogue which is better,
> obviously. The Cat Eye also does temperature and claims that its altitude
> tracking is more accurate because it adjusts for temperature. The Delphi
> 6.0 is also a heart rate monitor so if their altitude functions are equal
> then I'll go with it, but if the Cat Eye truly is a better altimeter then
> I'd get a separate HR monitor.
>
> Does anyone know anything about these altimeters, or have any

experience
> with them, that would be of value to me. Thanks in advance. :)
>
>


I cannot answer your question unfortumately. But I have an other related
question. In Holland, where I live, the Blackburn Delphi 6.0 should be
available in september 2005. I like this one because it has an altimeter and
a heart rate monitor combined for a reasonable price. But till now I cannot
buy one because of delivery problems in Holland. Is it possible to buy one
in other countries?
Does anybody have any experience with the Blackburn Delphi 6.0 ?

Thanks,

Hans
 
R

Robert

Guest
Hans wrote:
-----8<---cut

> In Holland, where I live, the Blackburn Delphi 6.0 should be
> available in september 2005. I like this one because it has an altimeter and
> a heart rate monitor combined for a reasonable price. But till now I cannot
> buy one because of delivery problems in Holland. Is it possible to buy one
> in other countries?
> Does anybody have any experience with the Blackburn Delphi 6.0 ?
>


Hans,

What kind of demand would there be for an altimeter in Holland?

;-) sorry ....

/Robert, living in not-exactly-mountainous Sweden
 
J

jtaylor

Guest
"Robert" <[email protected]> wrote in message
news:[email protected]
> Hans wrote:
> -----8<---cut
>
> > In Holland, where I live, the Blackburn Delphi 6.0 should be
> > available in september 2005. I like this one because it has an altimeter

and
> > a heart rate monitor combined for a reasonable price. But till now I

cannot
> > buy one because of delivery problems in Holland. Is it possible to buy

one
> > in other countries?
> > Does anybody have any experience with the Blackburn Delphi 6.0 ?
> >

>
> Hans,
>
> What kind of demand would there be for an altimeter in Holland?
>


You'd need a v-e-r-r-y sensitive one...
 
W

Werehatrack

Guest
On Thu, 2 Mar 2006 12:42:19 -0400, "jtaylor"
<[email protected]> wrote:

>
>"Robert" <[email protected]> wrote in message
>news:[email protected]
>> Hans wrote:
>> -----8<---cut
>>
>> > In Holland, where I live, the Blackburn Delphi 6.0 should be
>> > available in september 2005. I like this one because it has an altimeter

>and
>> > a heart rate monitor combined for a reasonable price. But till now I

>cannot
>> > buy one because of delivery problems in Holland. Is it possible to buy

>one
>> > in other countries?
>> > Does anybody have any experience with the Blackburn Delphi 6.0 ?
>> >

>>
>> Hans,
>>
>> What kind of demand would there be for an altimeter in Holland?
>>

>
>You'd need a v-e-r-r-y sensitive one...


And in places, one that measured depth as well as altitude...
--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.
 
R

Rik O'Shea

Guest
Altimeter of this sort do not actually measure altitude, they only
measure air pressure (similar to an aircraft altimeter). So the
altitude measurement is effectively a pressure-based measurement of
"pressure altitdue" (GPS performs a distance-based measurement of
actual altitude).

When these altimeters measure pressure they convert the pressure
measurement to the altitude defined in ISA which is simply a
mathematical model of atmosphere. The big problem with pressure based
altimeters is distinguishing between changes in pressure due to
altitude change (as you increase altitude pressure decreases) and
pressure changes due to the weather changing - generally speaking they
cant. Pilots periodically recalibrate using the altimeter air pressure
for a known altitude and you are supposed recalibrate your altimeter
before every ride - this process in itself is a little "ify" since it
generally based on knowing the current value for sea level air pressure
and your current altitude.

I suspect the Cat Eye baraometer temperature reading just reads
temperature and has no bearing on the altitude derivation. I own a
number of altimeters and they cant distingush between air pressure
change due to altitude change and/or weather change - despite the burb
about advanced algorithms...

Altimeters are great little gadgets and if you calibrate them before a
ride they are probably acurrate to +/- 3 m during the ride itself.
 
I had a cateye model about 5 years ago with the altimeter function.
Worked a few weeks then keep reseting on it's own. chucked it. While
it worked the altimeter function seemed somewhat accurate. Within a
few hundred feet at the high passes in colorado. You could adjust it
for varying air pressure but that was too much bother on a daily basis.

I have a planet bike computer with built in thermometer. It's rather
inaccurate. Direct sunlight runs the temp up an extra 10-15 degrees.
Ride with the unit in the shade of your body and the temp drops. The
sunnier the day, the more it heats up in that little plastic box.

Also have an Avocet watch with the altimeter function. A used gift.
Been sent in for repair many times by the previous owner. used it once
during a yosemite trip for fun.

So what do you want from an altimeter? Just to know your current
altitude? Total climb for the day's ride? Down load the days ride
into your pc and see a profile of the altitude changes? Calculate
percent grade during the ride? Or do you just want a toy with lots of
buttons.

For something much more advanced:
http://www.garmin.com/products/edge305/

Rick