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GPS Units = Show road steepness?



 
 
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  #31  
Old March 12th 19, 03:02 AM posted to rec.bicycles.tech
SMS
external usenet poster
 
Posts: 8,597
Default GPS Units = Show road steepness?

On 3/11/2019 1:23 PM, jbeattie wrote:

snip

I hate people on eBikes. But then again, I hate people on regular bikes. Traffic is traffic. With eBikes, though, you end up with otherwise unskilled riders who ride really fast in bike traffic. Fast dopes. Really fast unassisted riders are generally skilled -- not always, but generally. Imagine a pack of eBikers. It would make a Cat 5 race look safe.


Get ready for the eBike explosion in the U.S.. Costco is now selling an
eBike which one publication touted with "Is The Jetson Adventure E-Bike
Perfect?" for $1299.99. It is sufficient for most people's commuting
needs and it doesn't even really look like an eBike.

https://www.costco.com/Jetson-Adventure-Electric-Bike-.product.100370011.html

https://ridejetson.com/collections/bikes/products/adventure-electric-bike

Costco also periodically sells the GenZe eBike for around the same
price, with a larger motor and a throttle.

There's no real reason for eBikes to be costing $2000+, it's not that
much technology for a rear-hub motor wheel, a Li-Ion battery, and a
controller.



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  #32  
Old March 12th 19, 03:53 AM posted to rec.bicycles.tech
John B. Slocomb
external usenet poster
 
Posts: 805
Default GPS Units = Show road steepness?

On Mon, 11 Mar 2019 20:02:23 -0700, sms
wrote:

On 3/11/2019 1:23 PM, jbeattie wrote:

snip

I hate people on eBikes. But then again, I hate people on regular bikes. Traffic is traffic. With eBikes, though, you end up with otherwise unskilled riders who ride really fast in bike traffic. Fast dopes. Really fast unassisted riders are generally skilled -- not always, but generally. Imagine a pack of eBikers. It would make a Cat 5 race look safe.


Get ready for the eBike explosion in the U.S.. Costco is now selling an
eBike which one publication touted with "Is The Jetson Adventure E-Bike
Perfect?" for $1299.99. It is sufficient for most people's commuting
needs and it doesn't even really look like an eBike.

https://www.costco.com/Jetson-Adventure-Electric-Bike-.product.100370011.html

https://ridejetson.com/collections/bikes/products/adventure-electric-bike

Costco also periodically sells the GenZe eBike for around the same
price, with a larger motor and a throttle.

There's no real reason for eBikes to be costing $2000+, it's not that
much technology for a rear-hub motor wheel, a Li-Ion battery, and a
controller.


I see a 250W, 36V,rear wheel conversion kit listed on e-bay for as low
as Thai Baht 6,637, about US$207.
It appears to include the complete rear wheel but didn't seem to
specify the size.

--
Cheers,
John B.


  #33  
Old March 12th 19, 04:13 AM posted to rec.bicycles.tech
James[_8_]
external usenet poster
 
Posts: 5,975
Default GPS Units = Show road steepness?

On 12/3/19 1:00 pm, Mike A Schwab wrote:

For an instant reading, you can get a bubble inclineometer, properly
calibrated measures the incline between the front and rear contact
patches.


That would work for most bicycling, but for trick cyclists like Robbie
McEwan, who has been seen riding on one wheel going up hill, the GPS is
still better.

--
JS

  #34  
Old March 12th 19, 05:10 AM posted to rec.bicycles.tech
Sir Ridesalot
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Posts: 4,406
Default GPS Units = Show road steepness?

On Monday, March 11, 2019 at 10:00:31 PM UTC-4, Mike A Schwab wrote:
On Saturday, March 9, 2019 at 6:46:44 PM UTC-6, Sir Ridesalot wrote:
Talking about GPS units on another thread reminded me of something else I wondered if they do. Does a bicycle GPS unit show you the steepness of roads? There's an area that I frequently ride where on road has short but very steep hills, another road a mile or so east of it has much more gradual hills whilst a third road to the west of the first one is a major highway that can be ridden with a bicycle. What I'm wondering is this: if someone unfamiliar with the area got there and used a GPS unit to show those three roads, would the GPS unit show them the different gradients of the roads? Or is that another function that they'd need to download or otherwise install?

Cheers


For an instant reading, you can get a bubble inclineometer, properly calibrated measures the incline between the front and rear contact patches.


Doesn't do much good when you want to compare gradients of roads that run parallel or nearly parallel to each other in order to see which one would be easier to ride up.

Cheers
  #35  
Old March 12th 19, 05:14 AM posted to rec.bicycles.tech
Sir Ridesalot
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Posts: 4,406
Default GPS Units = Show road steepness?

On Monday, March 11, 2019 at 11:02:28 PM UTC-4, sms wrote:
On 3/11/2019 1:23 PM, jbeattie wrote:

snip

I hate people on eBikes. But then again, I hate people on regular bikes. Traffic is traffic. With eBikes, though, you end up with otherwise unskilled riders who ride really fast in bike traffic. Fast dopes. Really fast unassisted riders are generally skilled -- not always, but generally. Imagine a pack of eBikers. It would make a Cat 5 race look safe.


Get ready for the eBike explosion in the U.S.. Costco is now selling an
eBike which one publication touted with "Is The Jetson Adventure E-Bike
Perfect?" for $1299.99. It is sufficient for most people's commuting
needs and it doesn't even really look like an eBike.

https://www.costco.com/Jetson-Adventure-Electric-Bike-.product.100370011..html

https://ridejetson.com/collections/bikes/products/adventure-electric-bike

Costco also periodically sells the GenZe eBike for around the same
price, with a larger motor and a throttle.

There's no real reason for eBikes to be costing $2000+, it's not that
much technology for a rear-hub motor wheel, a Li-Ion battery, and a
controller.


Around here a 30 miles radius of ride is not that far. How long is the recharge time new and when the battery is old? I imaging that battery life drops a fair bit as it gets older? How long before the radius drops to 20 miles or less?
  #36  
Old March 12th 19, 05:37 AM posted to rec.bicycles.tech
John B. Slocomb
external usenet poster
 
Posts: 805
Default GPS Units = Show road steepness?

On Mon, 11 Mar 2019 22:14:02 -0700 (PDT), Sir Ridesalot
wrote:

On Monday, March 11, 2019 at 11:02:28 PM UTC-4, sms wrote:
On 3/11/2019 1:23 PM, jbeattie wrote:

snip

I hate people on eBikes. But then again, I hate people on regular bikes. Traffic is traffic. With eBikes, though, you end up with otherwise unskilled riders who ride really fast in bike traffic. Fast dopes. Really fast unassisted riders are generally skilled -- not always, but generally. Imagine a pack of eBikers. It would make a Cat 5 race look safe.


Get ready for the eBike explosion in the U.S.. Costco is now selling an
eBike which one publication touted with "Is The Jetson Adventure E-Bike
Perfect?" for $1299.99. It is sufficient for most people's commuting
needs and it doesn't even really look like an eBike.

https://www.costco.com/Jetson-Adventure-Electric-Bike-.product.100370011.html

https://ridejetson.com/collections/bikes/products/adventure-electric-bike

Costco also periodically sells the GenZe eBike for around the same
price, with a larger motor and a throttle.

There's no real reason for eBikes to be costing $2000+, it's not that
much technology for a rear-hub motor wheel, a Li-Ion battery, and a
controller.


Around here a 30 miles radius of ride is not that far. How long is the recharge time new and when the battery is old? I imaging that battery life drops a fair bit as it gets older? How long before the radius drops to 20 miles or less?


I wonder. Do people buy an e-bike for making long rides? Or do they
buy one to putter around the local village and do their shopping?

To be honest, I've never even seen an e-bike but I did look at some
electric powered three wheelers used to haul tourists around in
Singapore and talked with some of the Drivers?Owners? They use a
battery about the size of a large auto battery and I was told that
they would "go all day" although I'm not sure how long "all day"
actually is to a "Samlo" as I see them parked quite often. I don't
remember the costs but they were Chinese made hub matters and I do
remember at the time I though they were pretty cheap.

"Samlo" is a Thai word meaning three wheel and is used for the Thai
three wheelers. See https://tinyurl.com/y5rytxqp for both engine
powered and man powered versions.


--
Cheers,
John B.


  #37  
Old March 12th 19, 11:03 AM posted to rec.bicycles.tech
Duane[_4_]
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Posts: 1,519
Default GPS Units = Show road steepness?

Sir Ridesalot wrote:
On Monday, March 11, 2019 at 11:02:28 PM UTC-4, sms wrote:
On 3/11/2019 1:23 PM, jbeattie wrote:

snip

I hate people on eBikes. But then again, I hate people on regular
bikes. Traffic is traffic. With eBikes, though, you end up with
otherwise unskilled riders who ride really fast in bike traffic. Fast
dopes. Really fast unassisted riders are generally skilled -- not
always, but generally. Imagine a pack of eBikers. It would make a Cat 5 race look safe.


Get ready for the eBike explosion in the U.S.. Costco is now selling an
eBike which one publication touted with "Is The Jetson Adventure E-Bike
Perfect?" for $1299.99. It is sufficient for most people's commuting
needs and it doesn't even really look like an eBike.

https://www.costco.com/Jetson-Adventure-Electric-Bike-.product.100370011.html

https://ridejetson.com/collections/bikes/products/adventure-electric-bike

Costco also periodically sells the GenZe eBike for around the same
price, with a larger motor and a throttle.

There's no real reason for eBikes to be costing $2000+, it's not that
much technology for a rear-hub motor wheel, a Li-Ion battery, and a
controller.


Around here a 30 miles radius of ride is not that far. How long is the
recharge time new and when the battery is old? I imaging that battery
life drops a fair bit as it gets older? How long before the radius drops
to 20 miles or less?


Are you talking about full electric bikes? I was talking about a variable
assist. In that case I think it depends on how much you use it. My
friend’s wife uses it on hills and maybe into wind but otherwise she
pedals.

--
duane
  #38  
Old March 12th 19, 12:04 PM posted to rec.bicycles.tech
Rolf Mantel[_2_]
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Posts: 81
Default GPS Units = Show road steepness?

Am 10.03.2019 um 23:36 schrieb :

For every position on earth the altitude is known (measured during a
Space shuttle mission if I recall correctly). The information is
available for free.


The information is available but not in the necessary precision for road
gradients; uploading GPS tracks to Strava it is usually most meaningful
to replace the GPS altitude by 'true altitude' but look at the results:

https://www.strava.com/activities/1206896182

The first km, I am faster in the evening than in the morning so I assume
it's level or extremely slightly uphill, Strava thinks it's losing some
5m within 1 km.
Around km 1, there is a steep drop by 2m, followed by a climb of 2m
which is not visible at all in the track.

From km 6 to km 8 the track has a constant "climb" of 1m; Strava
interpolates a peak of 15m altitude into that which is not there in
reality.

Almost everything is correct to within a few m; the map-based
information produces a lot less spurious altitude gain and loss than the
GPS based information but this is not good enough for comparison of
gradients unless you're talking hills with 20m altitude gain or more.

I speculate my trip to work is 10m - 20m altitude gain in total on 11k
distance, the map brings it to 40m, GPS measurement typically around 60m.

Rolf
  #39  
Old March 12th 19, 12:38 PM posted to rec.bicycles.tech
Zen Cycle
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Posts: 108
Default GPS Units = Show road steepness?

On Monday, March 11, 2019 at 9:13:08 PM UTC-4, Ralph Barone wrote:
Radey Shouman wrote:
Zen Cycle writes:

On Sunday, March 10, 2019 at 6:35:02 PM UTC-4, Roger Merriman wrote:
Sir Ridesalot wrote:
Talking about GPS units on another thread reminded me of something else I
wondered if they do. Does a bicycle GPS unit show you the steepness of
roads? There's an area that I frequently ride where on road has short but
very steep hills, another road a mile or so east of it has much more
gradual hills whilst a third road to the west of the first one is a major
highway that can be ridden with a bicycle. What I'm wondering is this: if
someone unfamiliar with the area got there and used a GPS unit to show
those three roads, would the GPS unit show them the different gradients
of the roads? Or is that another function that they'd need to download or
otherwise install?

Cheers


Various mapping sites will show the gradient, and some GPS units will show
the gradient, in the same way that it can give improbable maximum speeds
they can also give improbable max gradients or sometimes on very short
ramps not notice it, there is a nasty little ramp nr my folks place, which
is the software flattens claiming 12% when it’s a fair cruel 25/30% even
more cruel this weekend with a 50mph headwind.

It's probably an averaging issue - taking enough samples before and
after the section so that it flattens the pitch.


It's the same basic issue as the speedometer kerfluffle. Numerical
differentiation amplifies noise.


I would think it was the opposite. Numerical integration suppresses spikes.


That's why I made the comment about the definition of 'noise'. I don't think differentiation is appropriate in this case, especially since we're doing simple math (not even algebra, let alone calculus).

  #40  
Old March 12th 19, 02:30 PM posted to rec.bicycles.tech
Radey Shouman
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Posts: 1,294
Default GPS Units = Show road steepness?

Zen Cycle writes:

On Monday, March 11, 2019 at 3:28:58 PM UTC-4, Radey Shouman wrote:
Zen Cycle writes:

On Sunday, March 10, 2019 at 6:35:02 PM UTC-4, Roger Merriman wrote:
Sir Ridesalot wrote:
Talking about GPS units on another thread reminded me of something else I
wondered if they do. Does a bicycle GPS unit show you the steepness of
roads? There's an area that I frequently ride where on road has short but
very steep hills, another road a mile or so east of it has much more
gradual hills whilst a third road to the west of the first one is a major
highway that can be ridden with a bicycle. What I'm wondering is this: if
someone unfamiliar with the area got there and used a GPS unit to show
those three roads, would the GPS unit show them the different gradients
of the roads? Or is that another function that they'd need to download or
otherwise install?

Cheers


Various mapping sites will show the gradient, and some GPS units will show
the gradient, in the same way that it can give improbable maximum speeds
they can also give improbable max gradients or sometimes on very short
ramps not notice it, there is a nasty little ramp nr my folks place, which
is the software flattens claiming 12% when it’s a fair cruel 25/30% even
more cruel this weekend with a 50mph headwind.

It's probably an averaging issue - taking enough samples before and
after the section so that it flattens the pitch.


It's the same basic issue as the speedometer kerfluffle. Numerical
differentiation amplifies noise.


Interesting how you characterize it as 'noise'.


For the speedometer the main source of noise is quantization error,
resulting from reducing a continuous wheel position to an integer number
of revolutions. For the 2-d field of altitudes obtained from a map I
suspect that the quantization of position, ie, the limited number of
data points, perhaps at irregular places, is the main source of noise.

How to turn topographical survey data into something that looks like a
continuous function is a whole field of study -- there are many ways to
go wrong, and no one perfect way to do it right.

In either case, errors that would be fairly small in altitude or
distance become larger when differentiated to estimate speed or
gradient.


--
 




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