tomato coupe

No one has stated that GPS is more accurate in all circumstances.

tomato coupe

I did not hand pick the data. The only rides on this route that were thrown out were ones that had obviously different start or stop points, e.g. a ride where I didn't hit the start button until I was already 1/4 mile down the road.
What difference could that possibly make? Are the roads different lengths on different days?

How about are you supposed to compare the repeatability of GPS-calculated distances if you use different routes?

No "snap to road" in my stuff.

indyfabz

I don't use GPS. If I am riding/touring in a unfamiliar area, I use PGS, which stands for Paper Guidance System, also known as cue sheets. Try starting a campfire with a GPS unit or cell phone absent battery asplosion.

wphamilton

As I said, I'm not implying anything about your data.

The equipment could change. The road could change.

All routes within a set should be the same. Don't cherry-pick the type of route to test. I get the feeling you're just being argumentative, because with a moment's thought you would have seen all this.

skenry

A few percent or a half mph is really a pretty close measurement, Much more accurate than your vehicles speedometer or a police radar gun. (generally calibrated to within 3 mph)

tomato coupe

The road could change??? You're really reaching now. (Even if the road did change, that would make GPS look worse than it really is.)

Cherry picking? You specifically proposed the following:
I did exactly what you proposed, and I did it by choosing a route that I had ridden many times with a consistent beginning and end. I'm not going to go out and repeat a bunch of routes of varying distance and terrain to satisfy your curiosity. Do it yourself.

tomato coupe

Isn't there an app for that?

philbob57

It's not an assumption. Many posters have written that they use their phones as bike computers. I believe them.

philbob57

I do not follow your meaning. I wrote that many riders use their phones as bike computers, which, I thought, requires the GPS functions. You called that a 'silly assumption.' I pointed out that the statement was not an assumption; rather, the statement was based on data. (BTW, you can check the data with the search function.)

My argument that GPSes are less reliable than sensors for distance and speed is based not on my difficulties but on data. You can't check the data about my rides, but you certainly can find lots of authoritative warnings that consumer-level (and probably military) GPSes don't do well under canopies of leaves, and leaves aren't the only obstacles.

That argument is pretty clear, and pretty clearly not silly or inane. If you disagree, fine ... come back with some facts and logical interpretations of those facts..

You started this dialog with an insult. You followed with 'silly,' 'inane,' 'please pay attention', and with 2 sentences that I find incomprehensible. I might respond if you post something on topic and understandable. I won't respond to more posts like #113.

And please don't quote me again. I really don't like the notifications.

wphamilton

well obviously. I am advising correct methodology, not a methodology that would make one hypothesis look better.

Nobody asked you to repeat any tests. You wanted to know why someone shouldn't cherry pick the type of route, and I explained why. If your integrity is ok with what you've presented, that's fine. Nobody is accusing you.

bbbean 

Depends on sampling rate and the pause settings (i.e., pause recording below 3 mph vs 5 mph vs while stopped). As a general rule, a computer using a speed sensor (your spoke magnet) shoudl be more accurate than a phone that is relying on GPS readings (variable by design) taken so many times per minute.

BB

tomato coupe

Your idea of correct methodology is to ride a route multiple times in a short time span,in case the road changes? Cmon man, let's stick with reality. The road isn't changing between rides -- if it does, everyone will know it.

I did not ask why someone shouldn't cherry pick data. You suggested riding the same route multiple times and comparing the results. I did that, but the results don't support your narrative, so now you're calling into question my selection of the route. By your standards, any chosen route would be cherry picked, and therefore would be called into question.

Maybe you shouldn't question my integrity, even in a thinly veiled way.

njkayaker

You can turn off the notifications.

philbob57

Thanks.

cjenrick

we are fortunate enough to have a bike path with mile markers , this Avocet is dialed in at +/- 0.01 miles per 5 mile trip,

depends on how much weaving we do,

don't use it anymore, too depressing, distracts from ride enjoyment,

it is the "dang, i thought i felt pretty good today but i am 2 minutes slower than yesterday when i felt like crap" syndrome.

good for total miles if you like to journal your rides, but we already have all the route miles figured out, jus sayin, wtf?

we like doing the same rides over and over again, familiarity - security, going on new rides gives me nervous diarrhea,

is that too much info? what are the rules at this forum on diarrhea?

locolobo13 

https://www.instructables.com/How-to...never%20before.

Actually I don't use GPS for measuring my rides. My GPS is an android. It often records jumps of up to half a mile. Teleportation?

Don't matter. I use it for a map of my rides later. Going thru pix later you can usually find exactly where you took the pic using Strava. And if somebody is interested in your ride you can share it.

indyfabz

I map out my tour routes on RWGPS ahead of time so I can see elevation gain, but I don’t rely on a device while riding. After the trip I map what I actually rode in case I deviated from the plan. As for photo locations, I use “memory chip” I was born with.