Comparing 2021 RWGPS to 2013 RWGPS

Probably because I was wasting time instead of doing what I should have been, 

I stumbled across this post from 2013:  "Johnson Mill Jaunt." 

 

While there is some amusing stuff near the bottom end of that 2013 post, 

[And make no mistake, I immediately shared that post with the "Irregulars" and 

Levi, the butt of the humor, responded to all of us with a "big fun" email.] 

The thing that drew my attention was the chart of RWGPS reported climbing per mile. 

 

I know / knew that RWGPS had modified their algorithms to estimate gross climbing, 

But until stumbling across the 2013 post, I didn't recall where to find evidence from before the change. 

 

On a bicycle forum and/or the randon-google-group-list-serve, 

I have mentioned the change in the RWGPS algorithms 

Which, it is my opinion, made the estimates for rolling hill routes less accurate 

While possibly maintaining the quality of the estimates for climbing mountains. 

 

At least one person parroted the RWGPS propoganda 

That the change was so that their estimates would more closely reflect 

The climbing reported by Garmin and other GPS devices. 

 

I responded with a politer version of "hogwash." 

As best I can recall, every person that has ridden the "Bahama Beach" route 

With a GPS device has reported climbing estimates ranging from 3200 to 3900 feet. 

The middling estimates of around 3500 to 3600 seem most frequent (and reasonable). 

 

Below is the reproduced chart from 2013, 

Followed by a revised chart showing the figures RWGPS reports today. 

And the total comparison summarized below that. 

 

The change ("reduction") varies considerably by route, but 

The average reduction of 23% is nothing to be sneezed at (i.e., ignored). 

 

Oh, as I have been known to say and/or type: 

NONE of the climbing estimates from ANY of the sources can be deemed "accurate." 

They can, however, provide some amusement as one or a group compares routes. 

 

	Route Name	2013 chart	miles	RWGPS	ft/m
1	-- errand ride --	Raleigh, NC	48.2	3,257	67.6
2	Rp - L-L-L Permanent	Raleigh, NC	127.1	8,093	63.7
3	R - NCBC 400k Brevet (2013)	Morrisville, NC	249.4	14,981	60.1
4	R - NCBC 300k Brevet (2013)	Morrisville, NC	189.9	10,818	57.0
5	IR - Johnson Mill Jaunt	Bay Leaf, NC	81.9	4,625	56.5
6	Rpp - Bahama Beach (std rte)	Bay Leaf, NC	64.6	3,587	55.5
7	Rpp - Howling Grits	Chatham, NC	64.3	3,567	55.5
	Route Name	2021 chart	miles	RWGPS	ft/m	reduced
1	-- errand ride --	Raleigh, NC	-- map not saved / no update --
2	Rp - L-L-L Permanent	Raleigh, NC	127.1	6,429	50.6	21%
5	R - NCBC 400k Brevet (2013)	Morrisville, NC	249.3	11,191	44.9	25%
7	R - NCBC 300k Brevet (2013)	Morrisville, NC	189.9	7,845	41.3	27%
3	IR - Johnson Mill Jaunt	Bay Leaf, NC	81.9	3,885	47.4	16%
4	Rpp - Bahama Beach (std rte)	Bay Leaf, NC	64.6	2,918	45.2	19%
6	Rpp - Howling Grits	Chatham, NC	64.3	2,810	43.7	21%
	2013 sum, excl "errand ride"		777.2	45,671	58.8
	2021 sum, excl "errand ride"		777.1	35,078	45.1	23%
	-- standard deviation of the six "reductions" reported --					4%