GPS vs indicated speed

I recently upgraded from the Reflex and my GPS always indicated 2-5 mph less than my indicated speed. So I got used to traveling at 60 believing I was going just above 55. Now on my Swing I also travel at indicated 60 and I find my GPS is also reading 60. Is the indicated speed on the Swing correct?

Keith
Iowa

Usually the speedo reads about 10% higher than actual.
Its that way from the factory. If you got one that is accurate,
thats a rarity.

My Swing also reads the correct speed.

dspevack wrote:

Usually the speedo reads about 10% higher than actual.
Its that way from the factory. If you got one that is accurate,
thats a rarity.

Mine also read 10% higher. I also have two friends with Silver wings and
theirs also reads 10% high.

Mine is also almost exactly 10% off.

Mine, too.

I find the GPS especially useful when returning to the UK - I don't have to do calculations to convert KPH to MPH.
The UK speed limits even appear on the GPS in KPH.

I was informed years ago that the motor industry built in the inaccuracy, usually between 2 to 10%.

No different to the aviation industry, however there dials and measuring readouts usually come with a table so that the +/- figures can be adjusted by the pilots.

The GPS I'm using was our first Tom Tom that also read a lower reading than indicated in my wifes car. At first I thought maybe it just read correctly up to 60 so I took it up to 80 and it still read dead on. Could it be something new on the 2010?

Keith
Iowa

Anything is possible, however I would suggest you do the following:

1. Go out to a highway.
2. Pull over to the emergency lane at a mile marker.
3. Reset your trip odometer.
4. Go on the road and pull over at the next mile marker.
5. Check accuracy of the odometer.

Why? Because those that have attempted to use devices to correct the inaccuracy of the speedometer, ended up developing an inaccuracy in the odometer, as the two are related.

If your odometer is accurate, do the following:

1. Secure a stopwatch to your handlebars.
2. Get up to 60 miles per hour.
3. Hit the stopwatch as you pass a mile marker.
4. Maintain 60 miles per hour for 5 miles.
5. Stop the stopwatch. It should show 5 minutes.

Why not do this for only 1 mile?
You may not be steady on the throttle. Nobody is perfect.
This is how you guarantee your speedometer accuracy.
Over 5 miles any inaccuracy should be apparent.

Good luck.

Dan

Boy oh boy!

At the risk of sounding like someone who has ridden billions of miles in the last month - This is really a whole lot of foolishness for a non-problem. Now I know there will be a whole lot of "what ifs..." that my calling this a non-problem will generate, so be it.

Unless you are doing a lot of events where you are navigating by keeping track of heading, time and distance - this GPS vs. Speedometer debate is little more than a grand exercise in typing.

I've never heard of a GPS reading greater than the SilverWing speedometer so just ride with an indicated speed that matches the posted and you'll be fine.

I have read before where the all awesome most high GPS by "manufacturer x" does not agree with another all awesome most high GPS made by "manufacturer y" or even with an older model made by "manufacturer x". Kind of makes them suspect.... I'm just sayin'...

You can install a speedometer correction device to correct the speedometer or the odometer. The odometer and the speedometer are off by different percentages. My SWing speedometer reads fast about 6.5% and the odometer read about 4% more miles than you really have traveled. Since the speedometer and the odometer are off by different percentages you can only set one or the other to read true. If you set the speedometer to read true than the odometer will read slightly low and if you set the odometer to read true than the speedometer will read slightly fast.

BTW … I can live with the inaccuracy!

http://www.dakotadigital.com/index.cfm/page/ptype=results/Category_ID=115/home_id=60/mode=cat/cat115.htm

http://www.healtech-electronics.com/

http://www.yellr.com/

Dale and Ron,
You both are of course correct.
But, some people are curious, and enjoy satisfying their curiousity.
All I did was post the steps to do that.

Ron...That's a heck of a stable! :not worthy:

Just sing louder !!!!!!!!!!!!

MaxB

I did not mean a foul -I do periodically check our speed using mile markers and I appreciate a simple solution.

I was once on a group ride where we were told we could not pass and that the ride would be at the posted speed. I was grateful when a fellow (not a leader) asked, "Is that indicated or GPS speed?" Why was I grateful? I now knew to avoid this knuckle head as he had self identified as an idiot. - What difference did it make indicated or GPS? I get curiosity, but stupidity, I struggle to comprehend that.

jdeereanton wrote:

I did not mean a foul -I do periodically check our speed using mile markers and I appreciate a simple solution.

I was once on a group ride where we were told we could not pass and that the ride would be at the posted speed. I was grateful when a fellow (not a leader) asked, "Is that indicated or GPS speed?" Why was I grateful? I now knew to avoid this knuckle head as he had self identified as an idiot. - What difference did it make indicated or GPS? I get curiosity, but stupidity, I struggle to comprehend that.

I see what you're saying it's just that some of us that had worked with scientist for years have this "need" to be acturate. Like I said at the start I though when I was running 60 indicated that I was only running 52-55, so that kind of explains why now nobody is passing me all the time when I'm going 60. Of course some still do but when I had the Reflex it seemed everyone had to pass me no matter what.

Keith
Iowa

I still work with scientists (little outfit called NASA) and I understand the need to be accurate. My wife and I don't ride our SilverWings to test the boundaries of their performance or to see if they conform to the spec sheet.

Living as we do in an environment that prizes power and speed we get passed an awful lot. Sometimes we are in the group doing the passing, sometimes not, mostly we ride to enjoy the ride and to get away from the race.

Probably just me. I do like the features a GPS provides. Don't have one for the SilverWings at present, even though our daughter-in-law has purchased us each one of DennisB's mounts. I even put them on the bikes already, but no GPS. We use them like a saddle pommel and hang our lariats off of them.

HMMM! I can see you going down the interstate lassoing 18 wheelers.
Craig




Who you will never catch streaking.

"Wow, there's a lot of speed demons out on the road today!"

When I first got my S Wing I noticed when I was driving to work on my normal route that cars were lining up behind me a lot. When I hooked up my GPS I realized it was because I was going around 49mph in a 55 zone.

Now that I correct for the speedo out of habit, I tend to keep up with the cars in front of me better and not get such a lineup behind me.

I always check the speedometers on vehicles I own. Both my Silverwing and Goldwing have about the same optomistic error, a bit under 10%. I really dislike instruments that don't read accurately so plan to install a yellowbox speedo calibrator on my GW since I tend to run faster on that bike than my SW. I have use my GPS on my SW right now to get a solid idea of what the actual speed on the GPS vs. the speedometer indication is for various operating speeds. I hate to hold up traffic by operating under the speed limit, it just irritates drivers behind you and can cause road rage problems. Being rather vulnerable to cages on the road I don't want to increase the problem.
GPS indicated speeds are quite accurate, I've tested my GPS against mile markers with my stopwatch several times and find it within one mile per hour of the timed stretches.
One thing that does irritate motorists are groups of motorcycles or scooters going below the speed limit in areas where it's nearly impossible to pass them. I distinctly remember getting behind about 40-50 Harleys in a group on a two lane road that were loafing along about 10mph below the limit. I was on my GW so I just worked my way through their staggered formation. If I'd been in a car it would have been impossible to pass them for many miles. Very irritating. I've never seen a group of bikes pull over even when many vehicles are held up behind them. In most states this is illegal.

This is interesting.
the Problem boils down to the individual.

I have a GPS, mostly for directions. But before I owned one, I used milemarkers. I usually had no problems, since i tend to drive fast.
Now this is going to sound funny, I use a cadence of white lines , using them as a tempo. Kinda like humming or a cadence. If you notice very few of us constantly look at the speedo. I go with the flow and a little more.

I have noticed white lines tend to keep the same cadence with the speed limit. Shorter cadence /lower speed limit. If you keep the cadence constant you are at the speed limit or close.

Scientifically accurate, I doubt it. Just an observation.

MaxB ( who sings out loud)

MaxB wrote:

I use a cadence of white lines , using them as a tempo. Kinda like humming or a cadence.
MaxB (who sings out loud)

I'm officially outing Max B.

His real name is......
















Hudson Hawk!


Would you like to swing on a star?

hahahahaha good one
MaxB

Flow of traffic works for me. At 75mph indicated, I know I'm only going 70mph on GPS. The speed display on the GPS is kinda tiny and I don't like looking away from the road that long, so I just follow the flow of traffic and when possible overtake and return to the cruising lane. If traffic is slow or non-existent to use as a gauge, I usually keep within 10mph indicated higher than the speed limit, cos then I know I'm about 3-5mph over the speed limit. Feels safer that way and works for me. I don't like to go too much faster than traffic cos I'm afraid of getting pulled over. I dunno how my sportbike buddies go 100+mph for any extended amount of time on the highways - I'd just be too worried about the cops!

Hammy wrote:

dunno how my sportbike buddies go 100+mph for any extended amount of time on the highways - I'd just be too worried about the cops!

Maybe you don't lie as much??

Hypothetically, if I was to admit doing something illegal, but I'm not, I could say that I've had the SW near it's top speed which indicated 110+ and 105mph on my GPS. The SW hypothetically handles just fine at that speed though the air flow over the top of my helment could have applied a strong upward pull on the helmet. If this had all happened it would be noted that the windshield didn't flex or bend at speed. If I were to do such an illegal and foolish thing I'd find me a long staight stretch of road go a mile or two to see if any radar photographers were present and then do a run back. If I'd done something like that, which of course I didn't I'd also have discovered my Goldwing 1800 would hit the rev limiter at 126mph. There's no doubt a SW can handle the freeway all day, they shouldn't have too much trouble on the Autobahn.

Max, Its gratifying you got the reference.

Personally my longest ride was from Miami to Knoxville Tennessee for the Honda Hoot.
I did 900 miles in a travel time of 13 hours (17 hours total with breaks for bathroom, food, and recaffination)
With the other stops I made on that trip, the round trip was 2,100 miles.
I probably ran a good portion of the trip just under redline, with no complaints from the bike.
I don't get the top speed some of you do even with the extra 6 HP, because I have a lot of wind resistance due to the clearview and some other stuff on the bike.
I top out around 100 flat.

When Im in the right lane Im slowing down, when I'm in the left lane I'm going fast, when I'm in the twists I'm going slowfastslowfastslowfast. My gps is in my bag for when i get lost.
To busy enjoying the ride to worry about 10% error, or if I'm getting 52 mpg.
Fill er up with regular buddy....

Oh I wish I could drive and not worry about my speed.

Unfortunately my commute takes me through a state park with rangers that like to earn that "little extra." Another town seems to have a sheriff's deputy stationed at the same bank parking lot 24 hours a day. When I drive by in the morning he's pointed one way, when I drive by in the evening he's pointed the other way.

All the cops around here have itchy trigger fingers, for the radar guns not the pistols.

I guess, I better change my riding position when trying to go 100 mph, I just got home from visiting the Honda dealer about 12 mi. away, when I hit 100 mph on the Freeway the SWing started wobbling realy bad, I got off the throttle, got Her under control, got home and changed my skivies. Think I learned a lesson. Ride Safe...Robert in Az.

Something's wrong there robert, my SW is steady as a rock at that speed. Have you checked your tires for pressure and balance? Possibly the steering head bearings might need checking possibly something loose in the forks. Also how about looseness in the swingarm ? Was there a strong or turbulent wind at the time? A wobble is a strong indication that something need to be looked at. I haven't experienced anything like you're describing at any speed with my SW.

Robert,
I'm with exavid on this. Have your bike checked!


Dan

DuggleBogey wrote:

"Wow, there's a lot of speed demons out on the road today!"

When I first got my S Wing I noticed when I was driving to work on my normal route that cars were lining up behind me a lot. When I hooked up my GPS I realized it was because I was going around 49mph in a 55 zone.

Now that I correct for the speedo out of habit, I tend to keep up with the cars in front of me better and not get such a lineup behind me.

This is exactly what I've been trying to say. When I was riding my Reflex at 60 I found out I was only going 53-55 which made me feel a little stupid. However, saying that I have still found my 2010 Swing to be dead on acturate. I wonder if they come from the factory that way and as we use them (tire wear and so on) it becomes about 10% off?

This fact has slowed me down a bit. I was used to going up past 70 thinking I was only going a little over 60, now I'm running along fine with the traffic flow at 65 (the speed limit on 4 lane roads).

I'm more used to the Relflex yet but I'm riding my Swing as much as possible. With my Reflex I sometimes did't even look at the speedometer cause I could tell pretty much by engine sound and tach readings. And ride I did, I put 35,000 miles on my 07, and yes I've done cross country which is the real way I love to ride.

Keith
Iowa

compguy wrote:

I wonder if they come from the factory that way and as we use them (tire wear and so on) it becomes about 10% off?

Not very likely.

jdeereanton wrote:

compguy wrote:

I wonder if they come from the factory that way and as we use them (tire wear and so on) it becomes about 10% off?

Not very likely.

Somehow this seems logical to me. The Honda quality seems to tell me that they would want the scooter to be as good as can be including acturate meters.

I'm sure you know more about this than I so please tell me your ideas.

I've heard that there were laws passed saying that speedometers have to read higher than they really are but I can't find any dependable source for this.

All I've tried is a Tom-Tom One and a Garmin 1390T and both read the same. I have also done the pace car and stop watch method however in all cases my new 2010 Swing seems acturate from 0-80mph.

Keith
Iowa

compguy wrote:

jdeereanton wrote:

compguy wrote:

I wonder if they come from the factory that way and as we use them (tire wear and so on) it becomes about 10% off?

Not very likely.

Somehow this seems logical to me. The Honda quality seems to tell me that they would want the scooter to be as good as can be including acturate meters.

It would seem logical, and yet, how would you explain the reality that more report the error than report the accuracy - regardless of model year or age or wear and tear?

compguy wrote:

I'm sure you know more about this than I...

Also - Not very likely.

compguy wrote:

I've heard that there were laws passed saying that speedometers have to read higher than they really are but I can't find any dependable source for this.

I'd say you are right to be skeptical as it is all just hearsay until someone can cite an authoritative reference. By the way, I've also heard that JFK and Elvis are alive and entertaining each other on a secluded island.

jdeereanton wrote:

By the way, I've also heard that JFK and Elvis are alive and entertaining each other on a secluded island.

Then it must be true ... just because someone said it :lol!:

Now there's a novelty! Sticking to the speed limits!!! I'm quite happy not knowing what I'm doing!

When the nice policeman stops you and you have your GPS on-line, thats your excuse gone out of the window. Whereas us non GPS riders!! have to be granted at least a ten per cent relaxation. (Don't we?)

Thats my excuse and I'm sticking to it!!

Or you could use the Brit excuse as used in Florida on the I95!!! Sorry officer I thought the speed limit was 95 mph like the signs say!!! (I believe that old chestnut isn't believed by the nice men in their cop cars anymore.) Still it was good whilst it lasted.

Waspie wrote:

Or you could use the Brit excuse as used in Florida on the I95!!! Sorry officer I thought the speed limit was 95 mph like the signs say!!!

Gee its a good thing he wasn't on Highway 441, or 826 (both local to miami)

compguy wrote:

... so please tell me your ideas.

I'd attribute a single report of a single scooter indicating a displayed speed that matches with the speed read out of that individuals GPS to a statistical anomoly.

Another little axiom I try to live by - Sometimes no matter how much we want it not to be - we just have to accept that it just is the way it is.

I know this works as it carried me through a few tank battles in my time.

One version of that joke:

A cop pulls over a carload of nuns.

Cop: "Sister, this is a 65 MPH highway -- why are you going so slow?"

Sister: "Sir, I saw a lot of signs that said 22, not 65."

Cop: "Oh sister, that's not the speed limit, that's the name of the highway you're on!

Sister: Oh! Silly me! Thanks for letting me know. I'll be more careful.

At this point the cop looks in the backseat where the other nuns are shaking and trembling.

Cop: Excuse me, Sister, what's wrong with your friends back there? They're shaking something terrible.

Sister: Oh, we just got off of highway 119.

Well I'd love to know the answer but I may never. I know what I will do is to keep checking mine as I ride more miles, although I understand this might not seem like it has anything to do with it I will test and give you a report later if it's ok.

Ok, well thanks to everyone for your response.

Keith
Iowa

Keith,

Of course it is okay - kind of goes without saying quite honestly.

You could be on to something. In my opinion, the variance you might discover will be so insignificant that it will not be statistically viable. But, if it is something that you are interested in or passionate about - pursue it fully.

And what do I think of GPS?

http://www.gocomics.com/nonsequitur/2010/10/29/

Jon

Jon,

tsk, tsk. The all awesome, most high, thoroughly infallible GPS is the answer to most of our problems. I'm with you by the way.

I especially love how the bike GPS using crowd will look upon the indicated speed with disdain because of the most high accuracy of the GPS, yet different model GPS' from the same manufacturer often do not agree with each other.

In this situation, I lean towards the old "ignorance is bliss" adage. That way I can take my chances with "I really don't know how fast I was going, from what I have read the speedometer is grossly inaccurate."

dspevack wrote:

Waspie wrote:

Or you could use the Brit excuse as used in Florida on the I95!!! Sorry officer I thought the speed limit was 95 mph like the signs say!!!

Gee its a good thing he wasn't on Highway 441, or 826 (both local to miami)

Silverwing with JATO bottles and afterburners fully on!!! =

Waspie wrote:

Silverwing with JATO bottles and afterburners fully on!!! =

Would the GPS display the correct MPH?

Of course I have no way to accurately verify my GPS. But I believe the "all powerful" GPS over my Speedo. Why?

When I drive the speed limit based on my speedo, I nearly get run over by all the people passing me.

When I drive the speed limit based on my GPS I don't.

Which would you tend to believe is more accurate in this case?

Hard to say since most people drive from 5 to 10 mph OVER the posted speed limit...

honda_silver wrote:

Waspie wrote:

Silverwing with JATO bottles and afterburners fully on!!! =

Would the GPS display the correct MPH?

At that speed - who cares!! I'd be too busy just hangin' on.