168mph On A 5th Gen

[Guest Dalewman]

168mph on a 5th gen:

I've narrowed it down to 3 possibilities:

1) There's a tear in space/time in Taliaferro County (bonus points for pronouncing Taliaferro correctly).

2) The bike and I fell out of a plane, which I'm pretty sure I would have remembered.

3) My GPS wigged out.

Anyone else had this problem of an absurdly high speed reading?

Also, after 1-15 minutes of riding, the GPS turns off. I've tried 3 different sets of batteries, so that's not it. It's a Garmin eTrex Legend. It will stay on all day on my desk, but on the bike it eventually turns off. I guess it's the vibration. Do you suppose plugging it in to a 12v socket would help?

Thanks for any input.

[doug5551]

I got this from Agirl's website :

http://seizethejourney.com/

Webmaster Note: 165mph MAX SPEED???? No wonder they got there and back in a day!!!

Actually, while GPS systems are usually quite accurate it doesn't take much of a "Glitch" to cause an error in a maximum or minimum reading such as "Max Speed." There are several causes of errors in GPS systems, and in most cases the errors are averaged out. The bottom line is that when working with GPS data timing is EVERYTHING!

The 24 GPS satellites are orbiting the Earth at a distance of about 12,000 miles, and they continually transmit information about their exact location above the Earth as well as the exact time that the information was transmitted. The GPS receiver takes this information from several satellites (a minimum of 3 is required for horizontal location information and a minimum of 4 is required for horizontal and vertical information) and computes the difference in the time one signal was received and the time the next signal was received. Using this information as well as the information about where the satellites are in orbit above the Earth it can calculate exactly where it is on the Earth, and it can do so very accurately.

The GPS receiver does this calculation many times a second, however it is, at heart, a computer. As we all know computers are very literal devices and have no imagination whatsoever. Occasionally satellites will update their internal clocks by a microsecond or so which can cause some slight errors. Additionally, there are certain errors caused by ionospheric delays, "Multipath" (reflections from nearby buildings, mountains, etc.) and other factors. Since the satellites are about 12,000 miles from the receiver and the radio signals travel at the speed of light (186,000 miles per second in a vacuum and slightly slower in atmosphere) it will take about 6/100 of a second for the signal to reach the receiver after it is transmitted by the satellite. To a computer accustomed to measuring things in nanoseconds 0.06 second is a long time. If there are delays in receiving the signal the computer in the GPS receiver thinks it has travelled farther than it actually has. If it takes only 1/100 of a second longer to reach the receiver that is already a 16.6% error in the timing. Since computers are, as mentioned, very literal they view "Maximum Speed" as exactly that, the MAXIMUM speed. They do not know whether that speed was caused by delays or other errors, they only know that for a period of time, a period that may well be only a microsecond in length, it calculated that speed. Short-duration errors in position and distance traveled are "Averaged Out" by subsequent receptions and calculations, but to a computer "Maximum" means "Maximum" so that is what it displays.

In short, while the overall numbers generated by GPS receivers are very accurate the "Maximum" and "Minimum" values are always questionable. I saw the "Maximum" speed on mine jump from 75 to 132 last week while cruising down the interstate.

[skuuter]

168mph on a 5th gen:

I've narrowed it down to 3 possibilities:

1) There's a tear in space/time in Taliaferro County (bonus points for pronouncing Taliaferro correctly).

2) The bike and I fell out of a plane, which I'm pretty sure I would have remembered.

3) My GPS wigged out.

Anyone else had this problem of an absurdly high speed reading?

Also, after 1-15 minutes of riding, the GPS turns off. I've tried 3 different sets of batteries, so that's not it. It's a Garmin eTrex Legend. It will stay on all day on my desk, but on the bike it eventually turns off. I guess it's the vibration. Do you suppose plugging it in to a 12v socket would help?

Thanks for any input.

For what it's worth, my 450 ZUMO started turning off on the bike when it was only a month old. It would charge up and stay up fine off the battery. It finally went off and I couldn't get it back on. It was still under warranty, so they replaced the whole unit (wood knocking sound).....has worked perfect ever since......if yours is out of warranty, I hope your problem is different.......... :blink:

[Beck]

You must have carried the GPS in your pants pocket when you got off the bike. Could have recorded how fast you had to put them down in your bathroom, after that wild ride! :goofy:

Or.........we can blame it again on the poor aliens......... No wonder they want to destroy us all! :blink:

Beck

95 VFR - Yes young man, she'll do 170, that the max on the speedo isnit!

[Guest]

WTF Aliens? Military experiment? GPS glitch?

Yeah...I've had issues with that too. Garmin eTrex Vista.

[oyama]

Actually, while GPS systems are usually...

...

...

...but to a computer "Maximum" means "Maximum" so that is what it displays.

Wow, now that is an explanation! :thumbsup:

[Guest]

Thanks for the input everyone.

Unfortunately, it's out of the warranty period.

I think I'll try the 12v route and see what happens.

[Dutchy]

For "mission critical" gps applications, a set of landbased receivers (called DGPS) are used to pick up the satelite signals and correct them (since the landbased location is fixed).

these corrections are then transmitted to be incorporated in the overall location determination.

[benSV]

eTrex is notoriously bad for shutting off from vibration.

It's OK on the VFR.. forget about using it on a V-Twin.. it will shut off every time you grab throttle and/or get to a certain RPM.

It's the battery contacts.. if you wire it up nicely to the bike it should stay on..

It will still die over time from vibration (as in break).

I've had two break (Vista).. first one Garmin replaced. Now I just don't care.

[Motor_Ref]

168mph on a 5th gen:

I've narrowed it down to 3 possibilities:

1) There's a tear in space/time in Taliaferro County (bonus points for pronouncing Taliaferro correctly).

2) The bike and I fell out of a plane, which I'm pretty sure I would have remembered.

3) My GPS wigged out.

Anyone else had this problem of an absurdly high speed reading?

Also, after 1-15 minutes of riding, the GPS turns off. I've tried 3 different sets of batteries, so that's not it. It's a Garmin eTrex Legend. It will stay on all day on my desk, but on the bike it eventually turns off. I guess it's the vibration. Do you suppose plugging it in to a 12v socket would help?

Thanks for any input.

Mine showed a ridiculously high speed once. I called Garmin and asked how it did that. I don't remember what they said to do, but it solved the problem. It has not happened again.

Good luck.

[swas]

Dalewman,

Just get used to it, as explained by Doug5551, atmospherics play a big role. I have used my Garmin Geko extensively whilst bush walking and it is a common problem, more so when around and under trees with wet leaves. Interestingly different types of trees create more extreme effects. If you have the facility to download your track from the GPS to your computer and load that track onto maps you can see where the GPS has put you to create these abnormalities in readout. It is quite hilarious sometimes.

In order to extend battery endurance I have tried in vain to carry mine around connected externally to a battery pack, the external connection is just not reliable enough to do that but I have not had any incidents using the internal batteries on walking trips, motorcycle trips, nor on-road and off-road bicycle rides.

]

GPS devices are not infallible, although when they are on song they are extremely accurate and good fun to use. A great way to calibrate your speedo 99% of the time!

[skuuter]

.....and I thought the Ruckus actually had hit 131 MPH sometime or other.............

[Guest]

You guys really shouldn't be fiddling with a camera at those speeds.

[soichiro]

I use mine with just the batteries and it doesnt shut off. I put it on the dirt bike once on a mx track and it would shut off.

My friend did 318mph on a wr450 dual sport. The gps doesnt lie right?

[Dutchy]

You guys really shouldn't be fiddling with a camera at those speeds.

I *think* that these units memorize the highest speed recorded versus the actual speed at the time..... :warranty:

[Guest]

If you really want a true reading of how fast you go, along with average speed, riding time, stopwatch, etc., get a Sigma Sport BC906 bicycle computer. For less than $30, get all that and a more accurate ground base reading. The one I have on the Ninja 250 said I did 109mph.

[Guest]

You guys really shouldn't be fiddling with a camera at those speeds.

Fiddling w/ the camera is the easy part. Getting the tripod to stay on the tank @ 168 is the real challenge.

[Bent]

.....and I thought the Ruckus actually had hit 131 MPH sometime or other.............

It probably did on Monteagle. I would believe it after following you up and down the mountain many times. :warranty:

[vfrcapn]

You guys really shouldn't be fiddling with a camera at those speeds.

Fiddling w/ the camera is the easy part. Getting the tripod to stay on the tank @ 168 is the real challenge.

Actually, getting the Throttlemeister locked down at that speed so you have both hands free to open the tank bag and take the camera and tripod out is the tough part..

:warranty:

[sirimiri]

You guys really shouldn't be fiddling with a camera at those speeds.

Fiddling w/ the camera is the easy part. Getting the tripod to stay on the tank @ 168 is the real challenge.

Actually, getting the Throttlemeister locked down at that speed so you have both hands free to open the tank bag and take the camera and tripod out is the tough part..

:warranty:

Have your pillion reach 'round and do it all for you!!!! :goofy:

[skuuter]

.....and I thought the Ruckus actually had hit 131 MPH sometime or other.............

It probably did on Monteagle. I would believe it after following you up and down the mountain many times. :warranty:

SSSHHhhhhhhhhh........don't blow the "old and slow" thing.................. :P

[HispanicSlammer]

some of the older garmins are not as powerful searching for satalites and lose contact then suddenly get contact again, thinking you moved from here to there in a shorter amount of time than you actually did it calculates a ginormous speed.

[Bent]

.....and I thought the Ruckus actually had hit 131 MPH sometime or other.............

It probably did on Monteagle. I would believe it after following you up and down the mountain many times. :wheel:

SSSHHhhhhhhhhh........don't blow the "old and slow" thing.................. :P

Hey Skuuter, want to go for a slow, scenic ride up Monteagle pretty soon? I can't go over 35 because my reflexes are diminishing week by week..... :goofy:

[skuuter]

.....and I thought the Ruckus actually had hit 131 MPH sometime or other.............

It probably did on Monteagle. I would believe it after following you up and down the mountain many times. :wheel:

SSSHHhhhhhhhhh........don't blow the "old and slow" thing.................. :P

Hey Skuuter, want to go for a slow, scenic ride up Monteagle pretty soon? I can't go over 35 because my reflexes are diminishing week by week..... :goofy:

I'm working on it.............. :thumbsup: