Suzuki Burgman USA Forum banner

Status
Not open for further replies.
1 - 20 of 33 Posts

·
Registered
Joined
·
3,411 Posts
Discussion Starter #1
As promised, I have conducted a thorough test of the speedometer and odometer on my Burgman 650, using a WAAS enabled 12-channel GPS as a reference.

I'll tabulate the data first, then describe my test protocols below that for any who are interested.

Odometer Error Test
(Distances in Statute Miles per Hour)

Odometer Reading: 100.7 miles
GPS Trip Odometer: 98.2 miles
Difference: 2.5 miles
Percent Error: 2.5% above true distance



Speedometer Error Test
(Speeds in Statute Miles per Hour)

Speedometer Reading..........GPS Speed Reading..........Difference............Percent High
..........30..........................................27.3..............................2.7.........................9.9%
..........45..........................................41.1..............................3.9.........................9.5%
..........60..........................................54.5..............................5.5.......................10.1%
..........66..........................................59.8..............................6.2.......................10.4%
..........70..........................................63.7..............................6.3.........................9.9%
..........90..........................................82.0..............................8.0.........................9.8%
........113..........................................102...............................11.........................10.8%
.........................................................................Average Speedometer Error: +10.0%


Testing Protocol

Testbed: 2003 Suzuki Burgman 650
Comparison Instrument: Garmin etrex GPS, with WAAS beacon receiver (Wide Area Augmentation System) activated for enhanced accuracy.

Procedure:

For speed testing, a selected speed was ridden for a minimum of 30 seconds. If the speed indicated on the vehicle's speedometer went above the target speed for even an instant, the test was voided and had to be repeated.

At the end of each test run, the GPS log was read for "Max Speed," and that number recorded next to the target speed. Then the "Max Speed" reading was reset for the next run.

This process enable the tester to keep watch on the vehicle speedometer without needing to cross-reference the GPS while the vehicle was in motion.

For the odometer testing, the vehicle was driven northbound on Interstate 5 between Everett, Washington and Mount Vernon, Washington for 48 miles as indicated on the vehicle's trip meter, then driven southbound on the same route with the GPS recording constantly. Including the distance to and from the freeway at each end of the run, total distance was 100.7 miles indicated.

Prior to starting each run the GPS signal strength was checked, and a minimum of 4 satellites had to be in view for the test to begin. At the end of each run, signal strength was again checked, and if full strength was not shown the test was voided and repeated.

It should be noted that the vehicle tested was factory stock, with 9,000+ miles on the original tires. Your results may vary.
 

·
Registered
Joined
·
3,411 Posts
Discussion Starter #2
Interesting to me was that the average speedometer error of 10% was exactly what several members have been estimating for some time. It makes compensating pretty simple.

The odometer error was half what I had been told one rider was getting, but more than what some others were expecting.

Most interesting of all (to me, anyway) was the maximum speed attained.

A year ago, with fewer than 1,000 miles on the bike, I was able to get the bike up to 112 MPH indicated on two tries.

Tonight, with a little over 9,000 miles on the bike and in similar conditions, I was able to get 113MPH indicated. Things seem to have "loosened up," even if only slightly.

Note that I do not condone or recommend anyone else riding this fast. I did this for testing purposes at 2:00AM in a well controlled environment on a stretch of 4-lane highway with no other traffic on it. Riding above the speed limit is done at your own risk.
 

·
Registered
Joined
·
611 Posts
Yeah - I'd attribute the odometer error to the high mileage tires. I wish the manufacturers would give us accurate speedometers. Why is it they always run them up optimistically anyway? It's not going to keep me below any speed limit - because I always follow with traffic, and it's not going to feed my ego to think I'm going fast either.
 

·
Registered
Joined
·
3,411 Posts
Discussion Starter #6
pauljo said:
Jim said:
I wonder what affect the older tires had, being smaller dia. than when newer. I would guess 1-2%.
Good point - and probably the primary cause of the odometer error.
I'll let you know tomorrow night. I'll be riding a low mileage '05 650 for a bit, and am bringing the GPS.
 

·
Registered
Joined
·
111 Posts
Brian,
Thanks for going to all this effort, it's really great to have the info. While I've only had my Burgie up to around 90 (and only for a few moments), I think that's probably about as fast as I'll ever go. I'll leave the top speed runs for you "Turbo" guys... :)

WLB :)
 

·
Registered
Joined
·
3,411 Posts
Discussion Starter #8
WLB :>) said:
Brian,
Thanks for going to all this effort, it's really great to have the info.
Doitashimashite.

I get a kick out of doing research and finding out all the niggling little details about stuff that interests me.

BTW; I suspect that the 2.5% odometer error can't be attributed -- at least not most of it -- to worn tires, because that would affect the speedometer as well; and the 10% speedometer error I got this week is exactly what I got last June during the first week I had it.

Also, the difference in tread depth between my tires now and when new can be measured in millimeters. Changing the tire pressure and loading would have more effect than that.

But, as mentioned, I'll know more tomorrow.
 

·
Registered
Joined
·
1,686 Posts
Here's my math contribution:

I measured my front tire's circumference at 1699mm for calibrating my bike trip computer. For the odometer to change 2.5% or .025, that would shrink the wheel to 1656.5mm, and the diameter would have shrunk 13.5mm (42.5/3.14) or .53" (more than 1/2 inch)!

As for increasing or decreasing air pressure in a tire, I don't think it will change an odometer reading much. Why? Because no matter how much air is in the tire, the distance around the tire remains the same. The length of the center tread section does not shrink or stretch. Tires do not inflate (grow) like a balloon. They just fill out and get stiffer as air pressure increases. Change to a larger or smaller diameter tire if you really want to effect the odometer calibration.
 

·
Registered
Joined
·
3,411 Posts
Discussion Starter #11
4DThinker said:
Here's my math contribution:

I measured my front tire's circumference at 1699mm for calibrating my bike trip computer. For the odometer to change 2.5% or .025, that would shrink the wheel to 1656.5mm, and the diameter would have shrunk 13.5mm (42.5/3.14) or .53" (more than 1/2 inch)!
Yep. I'm sure I haven't lost that much tread from my tires, so I don't think we can blame the 2.5% error soley on the old tire (which, BTW, still has 2mm of tread depth. How deep is new tread?).

4DThinker said:
...As for increasing or decreasing air pressure in a tire, I don't think it will change an odometer reading much. Why? Because no matter how much air is in the tire, the distance around the tire remains the same. ...
That's true, however a lower pressure will cause the contact patch to expand, creating a larger "standing wave" on the ground ahead of the vertical axis of the tire. This portion of the tire will not contribute to the "active circumference" so it can have a small effect on the odometer and speedometer, much the same as switching to a smaller diameter tire would. The degree to which it is affected could be computed by measuring the distance from the ground to the center of the axle at both the normal and the low pressure, and using the radii thus measured to compute the active circumferences of each using the formula 2R*Pi.

But, as you said, the effect is small.
 

·
Registered
Joined
·
3,411 Posts
Discussion Starter #13
captainfish said:
:scratch: :dontknow: :tard:
:lol: :lol: :lol:

And it was great meeting you, Captainfish. It was nice to finally see another 650 on the road. You need to get it checked, though, 'cause it must be hypothermic.

After all, it's turning blue. :wink:
 

·
Registered
Joined
·
553 Posts
No way

Brian said:
The odometer error was half what I had been told one rider was getting, but more than what some others were expecting.

Most interesting of all (to me, anyway) was the maximum speed attained.

A year ago, with fewer than 1,000 miles on the bike, I was able to get the bike up to 112 MPH indicated on two tries.

Tonight, with a little over 9,000 miles on the bike and in similar conditions, I was able to get 113MPH indicated. Things seem to have "loosened up," even if only slightly.

k.
I only have this to say(I've got better sense than to have any vehicle to 112,113 indicated). They say my 400 will do 95 but I'll never be dingy enough to find out. I wouldn't even drive my Chev Silverodo that fast, no way. To each his own I guess. :wink:
 

·
Registered
Joined
·
3,411 Posts
Discussion Starter #15
Re: No way

swstiles said:
...I've got better sense than to have any vehicle to 112, 113 indicated...
That's good.

As Dirty Harry once said, "A man has got to know his limitations." :p
 

·
Registered
Joined
·
130 Posts
Speedometer error

I also used a Garmin Etrex Legend GPS to check the speedometer error on my Burgman 650. I got the same 10% error so I also checked the accuracy of the GPS against my Dodge Dakota PU. The GPS was right on target with my PU speedometer- 70mph =70mph.
 

·
Premium Member
Joined
·
4,919 Posts
Thanks Brian, for the research and the post!

Captain fish's use of the emoticons slayed me! :D :D :D

Pete
 
1 - 20 of 33 Posts
Status
Not open for further replies.
Top