Topic: Zumo 665 speed not correct ? (Read 3033 times)

Mano · « **on:** October 17, 2011, 10:34:44 PM »

While riding this weekend i noticed that my Zumo 665 SPEED was 5 km (3.1 miles) LESS that my speedo. When my buddy pulled up beside me i asked him what his speedo said when we where cruising at 80 km. Confirming that the speedo was correct this means the Zumo 665 is showing the incorrect speed.

Is this normal or is my unit the only one?

dmnrdn · « **Reply #1 on:** October 17, 2011, 10:46:00 PM »

Have you given a thought that your speedo is wrong and the 665 is correct. Most speedos show faster than your actual speed. A gps is more accurate

Para Bellum · « **Reply #2 on:** October 17, 2011, 10:53:08 PM »

Quote from: dmnrdn on October 17, 2011, 10:46:00 PM

Have you given a thought that your speedo is wrong and the 665 is correct. Most speedos show faster than your actual speed. A gps is more accurate

X2

BUCKNUT GREG · « **Reply #3 on:** October 18, 2011, 12:15:52 AM »

Quote from: dmnrdn on October 17, 2011, 10:46:00 PM

Have you given a thought that your speedo is wrong and the 665 is correct. Most speedos show faster than your actual speed. A gps is more accurate

X3 gps more accurate. But hey it helps in speeding tickets Re.

jcraig147 · « **Reply #4 on:** October 18, 2011, 12:18:55 AM »

All the people I ride with are 2 miles fast....I go by my GPS

Joe

kiwihog · « **Reply #5 on:** October 18, 2011, 01:11:16 AM »

mine is the same I would believe the GPS it reads the same as my car and about 3mph over the RG

sadunbar · « **Reply #6 on:** October 18, 2011, 07:38:40 AM »

Quote from: BUCKNUT GREG on October 18, 2011, 12:15:52 AM

X3 gps more accurate. But hey it helps in speeding tickets Re.

x4

16HD117 · « **Reply #7 on:** October 18, 2011, 08:39:50 AM »

Quote from: dmnrdn on October 17, 2011, 10:46:00 PM

Have you given a thought that your speedo is wrong and the 665 is correct. Most speedos show faster than your actual speed. A gps is more accurate

X5

txhawg · « **Reply #8 on:** October 18, 2011, 09:17:54 AM »

GPS is always more accurate

North Georgia Hawg · « **Reply #9 on:** October 18, 2011, 09:43:15 AM »

Yeah... who you gonna believe? The $100,000,000,000 GPS satellite network staffed around the clock by the U.S. military and time corrected constantly to account for the precession in the Earth's orbit... or your Harley speedo? I'd go with the GPS network!

grc · « **Reply #10 on:** October 18, 2011, 10:15:15 AM »

Considering how cheap the rest of Harley's gauges are, I find it amazing that folks still think the speedometers are actually precise and accurate, or should be. The fact that they are only off a couple mph at 60 these days is a big improvement over the old stuff.

Jerry

mrmagloo · « **Reply #11 on:** October 18, 2011, 10:18:50 AM »

Let not forget that by setting the speedo's consistently 5%+ high, the bikes turn the miles quicker, and the warranty expires 5% sooner as well.

John53052 · « **Reply #12 on:** October 18, 2011, 10:59:54 AM »

That has always been my thought!!

Texas Fat Boy · « **Reply #13 on:** October 18, 2011, 11:51:16 AM »

GPS is closer to being right.

T-Hawk · « **Reply #14 on:** October 18, 2011, 12:13:28 PM »

Even in my Cage... trying different tire sizes and all, I've always trusted my GPS to tell me what my actual (closest to actual) speed was when traveling at highway speeds. Since the opening of the (more military than civilian) gps satellites back in the Clinton days... they have been reporting more and more accurate readings for not only position, but the calculations of speed traveled.

Midnight Rider · « **Reply #15 on:** October 18, 2011, 02:38:17 PM »

X6...believe the GPS, not the HD speedometer. With some tuning software, you can correct the speedo reading to be more accurate.

Just be glad we're not still dealing with a cable and gears stuck in the side of the transmission....

hotroadking · « **Reply #16 on:** October 18, 2011, 02:56:07 PM »

GPS

Also if you wish to get the speedo and GPS in close
to each other in reading using the TTS Mastertune you
can adjust the speedo factor to correct the speed
read on the bike.

I've got mine within 1 to 2 mph, it was 4 mph off..

I'd rather have the speedo reading a bit high
due to some high enforcement zones in our
local jurisdiction, a couple of extra MPH
helps keep you under the radar LOL

Mano · « **Reply #17 on:** October 18, 2011, 04:47:33 PM »

I believe you all BUT my buddy was on his Gold Wing and he was reading exactly 80 KM when my HD was reading 80 KM. Does this mean all bike speedo's are off ?

grc · « **Reply #18 on:** October 18, 2011, 04:55:11 PM »

Quote from: Mano on October 18, 2011, 04:47:33 PM

I believe you all BUT my buddy was on his Gold Wing and he was reading exactly 80 KM when my HD was reading 80 KM. Does this mean all bike speedo's are off ?

Wouldn't be surprised. Also wouldn't be surprised if you wouldn't have seen the same thing if you had a car pacing you as well. Vehicle speedo's all tend to read slightly high.

Jerry

mrmagloo · « **Reply #19 on:** October 18, 2011, 05:05:37 PM »

Quote from: grc on October 18, 2011, 04:55:11 PM

Wouldn't be surprised. Also wouldn't be surprised if you wouldn't have seen the same thing if you had a car pacing you as well. Vehicle speedo's all tend to read slightly high.

Jerry

x2 If you consider 5+% off as being 'slightly'.

Officially some mfr's judtify this from a safety perspective, which again is just BS. Every warranty should have a 5% extra miles cushion factor.

Midnight Rider · « **Reply #20 on:** October 18, 2011, 05:21:19 PM »

Quote from: Mano on October 18, 2011, 04:47:33 PM

I believe you all BUT my buddy was on his Gold Wing and he was reading exactly 80 KM when my HD was reading 80 KM. Does this mean all bike speedo's are off ?

Every vehicle I've owned since I've owned a GPS has been off anywhere from 2-4 mph....that's 5 bikes (Ducati, Yamaha, a Vrod, and 2 Ultras), a Subaru, a Toyota, and a Nissan.

The GPS is correct.

I've tweaked the TTS in my current bike to get the speedo within 1 mph of the GPS, just because I was already in there doing stuff anyway.

Mano · « **Reply #21 on:** October 18, 2011, 05:24:20 PM »

Quote from: TCnBham on October 18, 2011, 05:21:19 PM

Every vehicle I've owned since I've owned a GPS has been off anywhere from 2-4 mph....that's 5 bikes (Ducati, Yamaha, a Vrod, and 2 Ultras), a Subaru, a Toyota, and a Nissan.

The GPS is correct.

I've tweaked the TTS in my current bike to get the speedo within 1 mph of the GPS, just because I was already in there doing stuff anyway.

GPS it is.

How difficult was it to tweak the TTS?

Midnight Rider · « **Reply #22 on:** October 18, 2011, 05:29:13 PM »

Quote from: Mano on October 18, 2011, 05:24:20 PM

GPS it is.

How difficult was it to tweak the TTS?

Not difficult at all...there's a box that displays a number (either 4 or 5 digits) when you're loading a map. Increasing the number (making it higher), decreases the speedo reading. I think the pop up box includes information about how much to increase it to see a change. I forget...it's been more than 5 minutes since I did it

It's pretty obvious in the software though...

Mano · « **Reply #23 on:** October 18, 2011, 05:38:19 PM »

Quote from: TCnBham on October 18, 2011, 05:29:13 PM

Not difficult at all...there's a box that displays a number (either 4 or 5 digits) when you're loading a map. Increasing the number (making it higher), decreases the speedo reading. I think the pop up box includes information about how much to increase it to see a change. I forget...it's been more than 5 minutes since I did it

It's pretty obvious in the software though...

Thank you.

480Ruger · « **Reply #24 on:** October 18, 2011, 05:48:20 PM »

What was the TMAX number you used? 14XXX? I just got the 665 so don't know how much mine is off.

mrmagloo · « **Reply #25 on:** October 18, 2011, 06:04:51 PM »

If you have a Baker DD6, you can correct the speedo as well.

porthole · « **Reply #26 on:** October 19, 2011, 03:15:26 PM »

Sometime ago Power & Motor Yacht magazine did a speed comparison between a Garmin 276 (predecessor to the 478) a certified police hand held radar and a very sophisticated GPS based survey gizmo along with some lab tests.

The Garmin was deemed to be spot on and more accurate then the police radar.
I'd go with the GPS based system over any automotive type gauge that has a standard of accuracy of + - 10%

At least until the new cell systems are up and running and interfering with the GPS stuff - or enough satellites drop out of the loop and are not replaced.

charles05663 · « **Reply #27 on:** October 21, 2011, 03:18:13 PM »

This post came to mind about speedo vs GPS:

Quote from: kraut on March 05, 2010, 03:48:49 AM

Hi Klaus,

1. TomTom must show at least 5 km/h less: under German ans EC law speedos must show at least 5 km/h more than the actual speed. This does not apply to GPS-speed-readings,, they try to give you the "real" speed - wich is minimum 5 km/h less So with this difference at least your speedo should be reading allright.

2. as far as I remember, the ECM does not use speedo-information at all and I doubt the cruise control does, it's deducted from some other sensor-information, but don't ask me wich one. This is the line to check out I believe ...

5 km/h = 3.11 mph

Diamondback · « **Reply #28 on:** October 22, 2011, 12:26:59 AM »

Not that it matters now because clearly the Garmin or any GPS is more accurate. In fact at the standard +/- 30 feet of accuracy for the GPS signal, the Garmin under worst case conditions would be .8mph off at 70 mile per hour ( that is 69.2 to 70.

. Statistically it would no more than half of that in a normal mode so better than .4 mph. And under most conditions it would be even more accurate than that.

Go with the Garmin or any GPS device with average accuracy.

Author Topic: Zumo 665 speed not correct ? (Read 3033 times)