Wheel weight

On Wednesday, March 6, 2019 at 8:58:23 PM UTC+1, duane wrote:
On 06/03/2019 2:51 p.m., wrote:
On Wednesday, March 6, 2019 at 8:41:40 PM UTC+1, wrote:
On Wednesday, March 6, 2019 at 11:12:05 AM UTC-8, wrote:
On Wednesday, March 6, 2019 at 3:29:13 PM UTC+1, duane wrote:
On 06/03/2019 9:02 a.m., AMuzi wrote:
On 3/5/2019 9:55 PM, jbeattie wrote:
On Tuesday, March 5, 2019 at 7:28:17 PM UTC-8, James wrote:
On 6/3/19 12:47 pm, John B. Slocomb wrote:
On Tue, 5 Mar 2019 16:44:03 -0800, "Mark J."
wrote:


I think it's the trigonometry of the computation; the GPS (as I
understand it) measures distance to a collection of satellites whose
positions are well known, then computes location from triangulating
the
results.Â* I'm guessing that since most of the satellites are
usually not
directly overhead, but rather the line of sight to the satellite is
usually be much closer to tangential to the earth, then very small
errors in the distance-to-satellite computation turn into much larger
errors in the altitude computation.

I think this is why higher-end bike GPS's have a pressure-based
altimeter as well, to correct the fluctuations in the GPS-computed
altitude.Â* I know my Garmin Edge's regularly solicit known altitude
input at the start of a course.


I'm not sure about how accurate GPS really is but back in the day, the
seismic folks had a large "Black Box" that they used to locate their
seismic lines on the chart that they said was accurate to within feet.


Mark is pretty close to the correct reason. Most GPS receivers
intentionally track satellites that are close to the horizon as opposed
to direct overhead.Â* This is so that the X-Y part of the position
information is most accurate, at the expense of less accurate Z
position.


The overall accuracy depends greatly on the GPS receiver quality.Â* The
cheap receivers (say $50 ea) may be within a few meters, while expensive
receivers ($500) are 10 times better.Â* If you pay more ($10,000) and
incorporate corrections for atmospheric conditions and such, accuracy
can be better still.

The difference between cheap and expensive is largely down to the
stability of the oscillator used to time signals.Â* The antennas can also
be an expensive part and play a big role in accuracy and reflected
signal rejection.

But...Â* Even cheap GPS receivers are relatively stable over a short
time.Â* They usually produce a position, speed and heading once per
second.Â* The previous position, speed and heading are combined with new
measurements in a special filter, that usually results in better
accuracy than if the measurements were used alone.

The only times I've noticed real problems is when you cycle relatively
fast around tight corners.Â* The GPS position effectively cuts a little
off the corner each time, modelling it as a series of straight lines.
Hence your road speed appears to be slower than it really is and you
appear to accelerate again when the road straightens out.

More expensive GPS receivers can produce calculated position results
more frequently than 1 per second.Â* More powerful processor.Â* More power
consumption.Â* Unlikely to be in a battery operated consumer grade bike
computer.

But I find that they are accurate enough not to miss the magnet and reed
switch.

I have no instrumentation. I like surprises at the end of the ride
when I ask my fully instrumented riding buddies how far we went and
how much we climbed -- then I round up. No data to prove me wrong. I
adopt my son's power data when we're riding together since we're both
about the same weight, although he is all muscle and I'm muscle and
other things.Â* He gave me a Stages GPS Garmin-ish thing from work, but
I haven't put it on my bike. It sends me an e-mail every week
reminding me that I haven't ridden any miles.Â* That's super helpful.

-- Jay Beattie.





+1
I don't need to know; it's not why I ride.


I, on the other hand, am pretty wired up with my Garmin and Strava and
RideWithGPS. I like the stats to show my progress. I find the GPS helps
me when leading groups on rides that I don't know the route so well.
Less problematic than paper maps.

What's cool about cycling is that we are both happy with what we have.

GPS based cycling computers with navagation capabilities is one of the best and niciest cycling accesory IMO. Everything in one unit, never have to stop to look at a map, automatic logging and uploading, easy swap between bikes, clean cockpit, user definable datafield (number and content). What is there not to like?

https://photos.app.goo.gl/R11bCJx9DAaYHuDQA (map, cadence and power)

After my last crash we had a discussion with the insurance company of the woman I crashed into about my speed at the time of the crash. She accused me of excessive speed. I knew exactly my speed:

https://photos.app.goo.gl/vt8X8cetjpNfotfd9

That was settled then.

Lou

If you're not sure where you're going and they have a BICYCLE navigation feature they have advantages. But I can do the same thing with my smart phone minus the altitude function.

I doubt that. Does your phone have a battery life of 15-20 hours with the screen on? Can you use your phone in the rain without a clumsy cover?

Lou


I tried with my iPhone as well using RideWithGPS. In addition to your
points, I was rarely able to see the screen on sunny days.

That is also my experience. To able to use your phone to see were you are most of the times you have to stop, turn on the screen and hold your hand above the screen to be able to see anything. It is by far not the same as using your Garmin as you ride along.

Lou

On Wednesday, March 6, 2019 at 11:51:45 AM UTC-8, wrote:
On Wednesday, March 6, 2019 at 8:41:40 PM UTC+1, wrote:
On Wednesday, March 6, 2019 at 11:12:05 AM UTC-8, wrote:
On Wednesday, March 6, 2019 at 3:29:13 PM UTC+1, duane wrote:
On 06/03/2019 9:02 a.m., AMuzi wrote:
On 3/5/2019 9:55 PM, jbeattie wrote:
On Tuesday, March 5, 2019 at 7:28:17 PM UTC-8, James wrote:
On 6/3/19 12:47 pm, John B. Slocomb wrote:
On Tue, 5 Mar 2019 16:44:03 -0800, "Mark J."
wrote:


I think it's the trigonometry of the computation; the GPS (as I
understand it) measures distance to a collection of satellites whose
positions are well known, then computes location from triangulating
the
results.Â* I'm guessing that since most of the satellites are
usually not
directly overhead, but rather the line of sight to the satellite is
usually be much closer to tangential to the earth, then very small
errors in the distance-to-satellite computation turn into much larger
errors in the altitude computation.

I think this is why higher-end bike GPS's have a pressure-based
altimeter as well, to correct the fluctuations in the GPS-computed
altitude.Â* I know my Garmin Edge's regularly solicit known altitude
input at the start of a course.


I'm not sure about how accurate GPS really is but back in the day, the
seismic folks had a large "Black Box" that they used to locate their
seismic lines on the chart that they said was accurate to within feet.


Mark is pretty close to the correct reason. Most GPS receivers
intentionally track satellites that are close to the horizon as opposed
to direct overhead.Â* This is so that the X-Y part of the position
information is most accurate, at the expense of less accurate Z
position.


The overall accuracy depends greatly on the GPS receiver quality.Â* The
cheap receivers (say $50 ea) may be within a few meters, while expensive
receivers ($500) are 10 times better.Â* If you pay more ($10,000) and
incorporate corrections for atmospheric conditions and such, accuracy
can be better still.

The difference between cheap and expensive is largely down to the
stability of the oscillator used to time signals.Â* The antennas can also
be an expensive part and play a big role in accuracy and reflected
signal rejection.

But...Â* Even cheap GPS receivers are relatively stable over a short
time.Â* They usually produce a position, speed and heading once per
second.Â* The previous position, speed and heading are combined with new
measurements in a special filter, that usually results in better
accuracy than if the measurements were used alone.

The only times I've noticed real problems is when you cycle relatively
fast around tight corners.Â* The GPS position effectively cuts a little
off the corner each time, modelling it as a series of straight lines.
Hence your road speed appears to be slower than it really is and you
appear to accelerate again when the road straightens out.

More expensive GPS receivers can produce calculated position results
more frequently than 1 per second.Â* More powerful processor.Â* More power
consumption.Â* Unlikely to be in a battery operated consumer grade bike
computer.

But I find that they are accurate enough not to miss the magnet and reed
switch.

I have no instrumentation. I like surprises at the end of the ride
when I ask my fully instrumented riding buddies how far we went and
how much we climbed -- then I round up. No data to prove me wrong. I
adopt my son's power data when we're riding together since we're both
about the same weight, although he is all muscle and I'm muscle and
other things.Â* He gave me a Stages GPS Garmin-ish thing from work, but
I haven't put it on my bike. It sends me an e-mail every week
reminding me that I haven't ridden any miles.Â* That's super helpful.

-- Jay Beattie.





+1
I don't need to know; it's not why I ride.


I, on the other hand, am pretty wired up with my Garmin and Strava and
RideWithGPS. I like the stats to show my progress. I find the GPS helps
me when leading groups on rides that I don't know the route so well..
Less problematic than paper maps.

What's cool about cycling is that we are both happy with what we have.

GPS based cycling computers with navagation capabilities is one of the best and niciest cycling accesory IMO. Everything in one unit, never have to stop to look at a map, automatic logging and uploading, easy swap between bikes, clean cockpit, user definable datafield (number and content). What is there not to like?

https://photos.app.goo.gl/R11bCJx9DAaYHuDQA (map, cadence and power)

After my last crash we had a discussion with the insurance company of the woman I crashed into about my speed at the time of the crash. She accused me of excessive speed. I knew exactly my speed:

https://photos.app.goo.gl/vt8X8cetjpNfotfd9

That was settled then.

Lou

If you're not sure where you're going and they have a BICYCLE navigation feature they have advantages. But I can do the same thing with my smart phone minus the altitude function.

I doubt that. Does your phone have a battery life of 15-20 hours with the screen on? Can you use your phone in the rain without a clumsy cover?

Lou

Where do you ride your bike at 15-20 hours at a stretch?

On Wednesday, March 6, 2019 at 11:58:23 AM UTC-8, duane wrote:
On 06/03/2019 2:51 p.m., wrote:
On Wednesday, March 6, 2019 at 8:41:40 PM UTC+1, wrote:
On Wednesday, March 6, 2019 at 11:12:05 AM UTC-8, wrote:
On Wednesday, March 6, 2019 at 3:29:13 PM UTC+1, duane wrote:
On 06/03/2019 9:02 a.m., AMuzi wrote:
On 3/5/2019 9:55 PM, jbeattie wrote:
On Tuesday, March 5, 2019 at 7:28:17 PM UTC-8, James wrote:
On 6/3/19 12:47 pm, John B. Slocomb wrote:
On Tue, 5 Mar 2019 16:44:03 -0800, "Mark J."
wrote:


I think it's the trigonometry of the computation; the GPS (as I
understand it) measures distance to a collection of satellites whose
positions are well known, then computes location from triangulating
the
results.Â* I'm guessing that since most of the satellites are
usually not
directly overhead, but rather the line of sight to the satellite is
usually be much closer to tangential to the earth, then very small
errors in the distance-to-satellite computation turn into much larger
errors in the altitude computation.

I think this is why higher-end bike GPS's have a pressure-based
altimeter as well, to correct the fluctuations in the GPS-computed
altitude.Â* I know my Garmin Edge's regularly solicit known altitude
input at the start of a course.


I'm not sure about how accurate GPS really is but back in the day, the
seismic folks had a large "Black Box" that they used to locate their
seismic lines on the chart that they said was accurate to within feet.


Mark is pretty close to the correct reason. Most GPS receivers
intentionally track satellites that are close to the horizon as opposed
to direct overhead.Â* This is so that the X-Y part of the position
information is most accurate, at the expense of less accurate Z
position.


The overall accuracy depends greatly on the GPS receiver quality.Â* The
cheap receivers (say $50 ea) may be within a few meters, while expensive
receivers ($500) are 10 times better.Â* If you pay more ($10,000) and
incorporate corrections for atmospheric conditions and such, accuracy
can be better still.

The difference between cheap and expensive is largely down to the
stability of the oscillator used to time signals.Â* The antennas can also
be an expensive part and play a big role in accuracy and reflected
signal rejection.

But...Â* Even cheap GPS receivers are relatively stable over a short
time.Â* They usually produce a position, speed and heading once per
second.Â* The previous position, speed and heading are combined with new
measurements in a special filter, that usually results in better
accuracy than if the measurements were used alone.

The only times I've noticed real problems is when you cycle relatively
fast around tight corners.Â* The GPS position effectively cuts a little
off the corner each time, modelling it as a series of straight lines.
Hence your road speed appears to be slower than it really is and you
appear to accelerate again when the road straightens out.

More expensive GPS receivers can produce calculated position results
more frequently than 1 per second.Â* More powerful processor.Â* More power
consumption.Â* Unlikely to be in a battery operated consumer grade bike
computer.

But I find that they are accurate enough not to miss the magnet and reed
switch.

I have no instrumentation. I like surprises at the end of the ride
when I ask my fully instrumented riding buddies how far we went and
how much we climbed -- then I round up. No data to prove me wrong. I
adopt my son's power data when we're riding together since we're both
about the same weight, although he is all muscle and I'm muscle and
other things.Â* He gave me a Stages GPS Garmin-ish thing from work, but
I haven't put it on my bike. It sends me an e-mail every week
reminding me that I haven't ridden any miles.Â* That's super helpful.

-- Jay Beattie.





+1
I don't need to know; it's not why I ride.


I, on the other hand, am pretty wired up with my Garmin and Strava and
RideWithGPS. I like the stats to show my progress. I find the GPS helps
me when leading groups on rides that I don't know the route so well.
Less problematic than paper maps.

What's cool about cycling is that we are both happy with what we have.

GPS based cycling computers with navagation capabilities is one of the best and niciest cycling accesory IMO. Everything in one unit, never have to stop to look at a map, automatic logging and uploading, easy swap between bikes, clean cockpit, user definable datafield (number and content). What is there not to like?

https://photos.app.goo.gl/R11bCJx9DAaYHuDQA (map, cadence and power)

After my last crash we had a discussion with the insurance company of the woman I crashed into about my speed at the time of the crash. She accused me of excessive speed. I knew exactly my speed:

https://photos.app.goo.gl/vt8X8cetjpNfotfd9

That was settled then.

Lou

If you're not sure where you're going and they have a BICYCLE navigation feature they have advantages. But I can do the same thing with my smart phone minus the altitude function.

I doubt that. Does your phone have a battery life of 15-20 hours with the screen on? Can you use your phone in the rain without a clumsy cover?

Lou


I tried with my iPhone as well using RideWithGPS. In addition to your
points, I was rarely able to see the screen on sunny days.

Well, I can't see mine either. But what's to see? It calls out impending turns with the screen off.

On 06/03/2019 3:07 p.m., wrote:
On Wednesday, March 6, 2019 at 8:58:23 PM UTC+1, duane wrote:
On 06/03/2019 2:51 p.m., wrote:
On Wednesday, March 6, 2019 at 8:41:40 PM UTC+1, wrote:
On Wednesday, March 6, 2019 at 11:12:05 AM UTC-8, wrote:
On Wednesday, March 6, 2019 at 3:29:13 PM UTC+1, duane wrote:
On 06/03/2019 9:02 a.m., AMuzi wrote:
On 3/5/2019 9:55 PM, jbeattie wrote:
On Tuesday, March 5, 2019 at 7:28:17 PM UTC-8, James wrote:
On 6/3/19 12:47 pm, John B. Slocomb wrote:
On Tue, 5 Mar 2019 16:44:03 -0800, "Mark J."
wrote:


I think it's the trigonometry of the computation; the GPS (as I
understand it) measures distance to a collection of satellites whose
positions are well known, then computes location from triangulating
the
results.Â* I'm guessing that since most of the satellites are
usually not
directly overhead, but rather the line of sight to the satellite is
usually be much closer to tangential to the earth, then very small
errors in the distance-to-satellite computation turn into much larger
errors in the altitude computation.

I think this is why higher-end bike GPS's have a pressure-based
altimeter as well, to correct the fluctuations in the GPS-computed
altitude.Â* I know my Garmin Edge's regularly solicit known altitude
input at the start of a course.


I'm not sure about how accurate GPS really is but back in the day, the
seismic folks had a large "Black Box" that they used to locate their
seismic lines on the chart that they said was accurate to within feet.


Mark is pretty close to the correct reason. Most GPS receivers
intentionally track satellites that are close to the horizon as opposed
to direct overhead.Â* This is so that the X-Y part of the position
information is most accurate, at the expense of less accurate Z
position.


The overall accuracy depends greatly on the GPS receiver quality.Â* The
cheap receivers (say $50 ea) may be within a few meters, while expensive
receivers ($500) are 10 times better.Â* If you pay more ($10,000) and
incorporate corrections for atmospheric conditions and such, accuracy
can be better still.

The difference between cheap and expensive is largely down to the
stability of the oscillator used to time signals.Â* The antennas can also
be an expensive part and play a big role in accuracy and reflected
signal rejection.

But...Â* Even cheap GPS receivers are relatively stable over a short
time.Â* They usually produce a position, speed and heading once per
second.Â* The previous position, speed and heading are combined with new
measurements in a special filter, that usually results in better
accuracy than if the measurements were used alone.

The only times I've noticed real problems is when you cycle relatively
fast around tight corners.Â* The GPS position effectively cuts a little
off the corner each time, modelling it as a series of straight lines.
Hence your road speed appears to be slower than it really is and you
appear to accelerate again when the road straightens out.

More expensive GPS receivers can produce calculated position results
more frequently than 1 per second.Â* More powerful processor.Â* More power
consumption.Â* Unlikely to be in a battery operated consumer grade bike
computer.

But I find that they are accurate enough not to miss the magnet and reed
switch.

I have no instrumentation. I like surprises at the end of the ride
when I ask my fully instrumented riding buddies how far we went and
how much we climbed -- then I round up. No data to prove me wrong. I
adopt my son's power data when we're riding together since we're both
about the same weight, although he is all muscle and I'm muscle and
other things.Â* He gave me a Stages GPS Garmin-ish thing from work, but
I haven't put it on my bike. It sends me an e-mail every week
reminding me that I haven't ridden any miles.Â* That's super helpful.

-- Jay Beattie.





+1
I don't need to know; it's not why I ride.


I, on the other hand, am pretty wired up with my Garmin and Strava and
RideWithGPS. I like the stats to show my progress. I find the GPS helps
me when leading groups on rides that I don't know the route so well.
Less problematic than paper maps.

What's cool about cycling is that we are both happy with what we have.

GPS based cycling computers with navagation capabilities is one of the best and niciest cycling accesory IMO. Everything in one unit, never have to stop to look at a map, automatic logging and uploading, easy swap between bikes, clean cockpit, user definable datafield (number and content). What is there not to like?

https://photos.app.goo.gl/R11bCJx9DAaYHuDQA (map, cadence and power)

After my last crash we had a discussion with the insurance company of the woman I crashed into about my speed at the time of the crash. She accused me of excessive speed. I knew exactly my speed:

https://photos.app.goo.gl/vt8X8cetjpNfotfd9

That was settled then.

Lou

If you're not sure where you're going and they have a BICYCLE navigation feature they have advantages. But I can do the same thing with my smart phone minus the altitude function.

I doubt that. Does your phone have a battery life of 15-20 hours with the screen on? Can you use your phone in the rain without a clumsy cover?

Lou


I tried with my iPhone as well using RideWithGPS. In addition to your
points, I was rarely able to see the screen on sunny days.

That is also my experience. To able to use your phone to see were you are most of the times you have to stop, turn on the screen and hold your hand above the screen to be able to see anything. It is by far not the same as using your Garmin as you ride along.


Our club rides are hosted on RideWithGPS though and with the club
account you can use the app to get turn by turn voice commands. Some of
the members that don't have Garmins or similar use the phone for that
and keep it in their pocket or whatever.

On Wednesday, March 6, 2019 at 7:37:22 AM UTC-8, wrote:
On Tuesday, March 5, 2019 at 2:41:33 PM UTC-8, James wrote:
On 6/3/19 2:48 am, wrote:
On Tuesday, March 5, 2019 at 7:45:36 AM UTC-8, wrote:


The carbon clinchers: Front; 1.13 Kg Rear with 11-29 cassette; 1.58 Kg.

That is with tires and tubes. And the speedo magnet.


If you changed to a Garmin or other GPS based speedometer, you could
save valuable grams from the front wheel because there's no need for a
magnet.

--
JS

Firstly a GPS based system is not accurate - all of those ups and downs are not counted and on a long ride can add up to several miles. Secondly, the wheel magnets I use weigh less than one gram.

I am always amazed that people think that "modern technology" is better than older simply because it is newer.

Well, those people who love all the functions love all the functions. That's fine.

Some of the services can be used for creepy purposes like Strava stalking. Connectivity can be a curse. I have three friends who were cutting through a forest trail on their road bikes just for something different and some irate crazed woman with a dog (illegally off a leash) started yelling at them and confronting them about being on the trial. They squeezed by and split, but next thing they knew, she had their Strava information and their identities and was contacting their employers and claiming she was assaulted. She even made a big stink at city hall. You never know when you're going to encounter a crazy person.

-- Jay Beattie.

On Wednesday, March 6, 2019 at 11:19:45 AM UTC-5, Frank Krygowski wrote:
Snipped

Back in the mid-1980s I got my first cyclometer. For me, it was useful
motivation for training - as in "I'm only going 19 mph? I can go faster
than that!"

Nowadays the data is just depressing. I try not to look at it too much.

--
- Frank Krygowski

I guess that's why some people mount the cyclometer on their seatpost or seat-tube = so they aren't tempted to look at it whilst riding. Yet they have their accumulated mileage at the end of the ride.

Cheers

On 3/6/2019 6:04 PM, Sir Ridesalot wrote:
On Wednesday, March 6, 2019 at 11:19:45 AM UTC-5, Frank Krygowski wrote:
Snipped

Back in the mid-1980s I got my first cyclometer. For me, it was useful
motivation for training - as in "I'm only going 19 mph? I can go faster
than that!"

Nowadays the data is just depressing. I try not to look at it too much.

--
- Frank Krygowski

I guess that's why some people mount the cyclometer on their seatpost or seat-tube = so they aren't tempted to look at it whilst riding. Yet they have their accumulated mileage at the end of the ride.

Very, very vaguely related: On my folding bike, I installed a Cateye
wireless cyclometer, figuring any wire would eventually get ripped apart
during the frequent folds and unfolds.

But at temperatures less than about 45 Fahrenheit, it would lose contact
with the sending unit. It would say Zero miles per hour, even though I
was sure I was going a _little_ faster than that.

Changing batteries in the sender or display units didn't help. Shifting
the sender to different positions, ahead and behind the fork, didn't
help. I finally fabricated a separate little stub mount to keep the
display part about an inch in front of my handlebar. That seemed to cure
the problem. I guess the handlebar itself was blocking the radio signal.

My wife's identical bike has a much cheaper Echo brand wireless
cyclometer. It has no such problem.


--
- Frank Krygowski

On Wednesday, March 6, 2019 at 2:54:56 PM UTC-8, jbeattie wrote:
On Wednesday, March 6, 2019 at 7:37:22 AM UTC-8, wrote:
On Tuesday, March 5, 2019 at 2:41:33 PM UTC-8, James wrote:
On 6/3/19 2:48 am, wrote:
On Tuesday, March 5, 2019 at 7:45:36 AM UTC-8, wrote:


The carbon clinchers: Front; 1.13 Kg Rear with 11-29 cassette; 1.58 Kg.

That is with tires and tubes. And the speedo magnet.


If you changed to a Garmin or other GPS based speedometer, you could
save valuable grams from the front wheel because there's no need for a
magnet.

--
JS

Firstly a GPS based system is not accurate - all of those ups and downs are not counted and on a long ride can add up to several miles. Secondly, the wheel magnets I use weigh less than one gram.

I am always amazed that people think that "modern technology" is better than older simply because it is newer.

Well, those people who love all the functions love all the functions. That's fine.

Some of the services can be used for creepy purposes like Strava stalking.. Connectivity can be a curse. I have three friends who were cutting through a forest trail on their road bikes just for something different and some irate crazed woman with a dog (illegally off a leash) started yelling at them and confronting them about being on the trial. They squeezed by and split, but next thing they knew, she had their Strava information and their identities and was contacting their employers and claiming she was assaulted. She even made a big stink at city hall. You never know when you're going to encounter a crazy person.

-- Jay Beattie.

Well, I don't know how you're going to avoid lunatics as long as you have Frank and Slocumb here.

On Wed, 6 Mar 2019 19:21:31 -0500, Frank Krygowski
wrote:

On 3/6/2019 6:04 PM, Sir Ridesalot wrote:
On Wednesday, March 6, 2019 at 11:19:45 AM UTC-5, Frank Krygowski wrote:
Snipped

Back in the mid-1980s I got my first cyclometer. For me, it was useful
motivation for training - as in "I'm only going 19 mph? I can go faster
than that!"

Nowadays the data is just depressing. I try not to look at it too much.

--
- Frank Krygowski

I guess that's why some people mount the cyclometer on their seatpost or seat-tube = so they aren't tempted to look at it whilst riding. Yet they have their accumulated mileage at the end of the ride.

Very, very vaguely related: On my folding bike, I installed a Cateye
wireless cyclometer, figuring any wire would eventually get ripped apart
during the frequent folds and unfolds.

But at temperatures less than about 45 Fahrenheit, it would lose contact
with the sending unit. It would say Zero miles per hour, even though I
was sure I was going a _little_ faster than that.

Changing batteries in the sender or display units didn't help. Shifting
the sender to different positions, ahead and behind the fork, didn't
help. I finally fabricated a separate little stub mount to keep the
display part about an inch in front of my handlebar. That seemed to cure
the problem. I guess the handlebar itself was blocking the radio signal.

I use a conventional speedometer to measure pedal rpm by modifying the
settings. The sender is mounted on the chain stay and the display on
the top tube. In several cases I have had the display not see the
sender signal, and checking, it was as you say, the top tube blocking
the signal. The cure is always to move the display back, closer to the
sender. Apparently signal strength is important :-)


My wife's identical bike has a much cheaper Echo brand wireless
cyclometer. It has no such problem.

--
Cheers,
John B.

On 7/3/19 1:35 am, Zen Cycle wrote:


There's also the ability to track more than a few satellites.
Mathematically you only need three for acquisition, but the more
satellites you track, the more accurate your calculation will be.
Early and chepaer GPS units would only track three or four, since the
smaller microcontrollers can only handle juggling so much data. More
elaborate GPS systems will track as many satellites as they can see.
A system I worked on recently could log up to 26 at once, though we
generally considered 9 to be optimal for the system architecture and
the application.


Yes, and even relatively cheap modern receivers can track not only more
US satellites, but also Russian and Chinese satellites, like this.

https://www.u-blox.com/en/product/sparkfun-gps-receiver

--
JS