Bicycle Computers - what do they do?

In article <[email hidden]>,

Michael J. Klein said:

Ryan Cousineau said:

In article <[email hidden]>,

<snip>

Quoted message said:

Cateye makes the CC-HB100 heart rate cyclecomputer. I
have one, and would be really happy with it if it had 2-
bike wheel memory and recorded Max heartrates.

It's quite common to have a bike computer and then a
separate heart rate monitor, but I believe some Polaris
bike-specific models integrate some fairly funky features
(the CC-HB100 integrates a fairly bogus "calorie counter"
based on heart rate and speed, but it doesn't even have
an entry for rider mass, so I would suggest it is only
useful as a relative effort measurement).

Hmmm... gives me some new product ideas. I'll be talking
with some suppliers on Monday.

Well, as long as you're taking requests, here's my
dream computer:

-Heartrate, cadence, and oh, how about an Avocet-style
altimeter? -Heart rate computer should remember peak and
average HR; the Cateye also has programmable range
indicators, in which it puts up a little arrow if your HR is
above or below the numbers you put in. -Average and peak
cadence memory, too. -use the altimeter and speedometer to
generate instant VAM (see Dr. Ferrari) numbers! -allow user
to enter their weight. Use that to generate a not-entirely-
bogus calorie-meter, but also to...generate moderately
accurate power output numbers, at least on hills! -must be
able to handle two wheel sizes. Three would be even nicer,
but not necessary. A corollary is that making extra wiring
harnesses available for a nominal cost is a nice advantage.
Cateye does this, though the last time I checked I ended up
buying a computer, because it cost $5 more for the cheap
computer than for the separate harness.

-Downloadable-to-PC data is cool, but probably adds too much
cost. -I have little interest in wireless units (except, for
obvious reasons, the heart rate transmitter) because I am
allergic to buying batteries. But it's probably a market
advantage.

Note that the competition in the low-end computer market has
taken a turn for the weird. Filzer now makes a competent non-
cadence computer for a price that, at wholesale, must be
remarkably close to nothing:

filzer.comcatalog.htmlOpen ↗

The MEC listings:

tinyurl.com22l4qOpen ↗

The full-featured dB4L is C$14.50. There's a dB2L for
$12.50, but I don't think that's enough price difference to
sway anyone. It's possible the cheap computer only exists to
make the 4L look like an even better deal.

And then there's the dB4W, the wireless version of the
4L. it's C$24.00. That's less than USD$18. For a
wireless computer.

Now for the bad news: Filzer has started making HRMs now,
too. Performance doesn't sell them under the Filzer name,
but the high-end one costs $50:

performancebike.comlarge photo.cfmOpen ↗
63&Store=Bike

Share & Enjoy,
--
Ryan Cousineau, [email hidden]
sfu.cawiredcolaOpen ↗ President, Fabrizio
Mazzoleni Fan Club

Captain's log. On StarDate Sat, 26 Jun 2004 09:36:06 +0800 received comm from
Michael J. Klein <[email hidden]> on channel rec.bicycles.tech:

: I use a GPS on my bike. I've read some info about bike
: computers, and it seems like they don't do anything that
: my GPS does. Is that a correct assessment? Also, I would
: like to know more about bike

No.

I don't think your GPS will do for example:

Cadence Heart Rate Power

: computers and I will read any suggested information.

polarusa.comS720.aspOpen ↗

Best regards,

martin törnsten

--
82.182.73.12682.182.73.126Open ↗

Michael J. Klein said:

I use a GPS on my bike. I've read some info about bike
computers, and it seems like they don't do anything that my
GPS does. Is that a correct assessment? Also, I would like
to know more about bike computers and I will read any
suggested information.

In their simplest common form, they count the wheel
rotations and their durations, and calculate and display the
information that can be derived from that raw data; current
speed, distance traveled, average speed, etc. More
sophisticated units also sense, calculate and display gear
ratio and pedalling cadence. There are also units which
engage in biomonitoring of the rider, but I place those in a
different category since they are monitoring more than just
the bicycle.
--
Typoes are a feature, not a bug. Some gardening required to
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Michael J. Klein said:

I use a GPS on my bike. I've read some info about bike
computers, and it seems like they don't do anything that my
GPS does.

A GPS tends to give an approximation of distance travelled
based on apparent movement within the mapped space. The
inability of the instrument to detect minor changes in
position makes this a less accurate method of measurement of
motion for a bicycle than the more direct method used by the
on-board physically linked computer, which gives a
calculation based on measured wheel motion. A wiggly path
can make a short direct-line distance into a much longer
actual trip.

--
Typoes are a feature, not a bug. Some gardening required to
reply via email. Surrealism is a pectinated ranzel.