Speedometer Error

Thunderchief

Thunderchief

Joined
Oct 25, 2014
Messages
78
Age
89
Location
Waynesville, NC
Bike
2007 Honda ST1300
I suspect I am not the only guy who has an ST with a speedometer that reads much higher than the speed but I could not find a "thread" on this subject. Anyway my speedometer reads 6 mph higher than the GPS speed. Is there a way to calibrate the speedometer on a 2007 ST1300?
 
In the UK there is a company that calibrates your actual speedo, there must be someone who does this in the US.
 
I don't bother using the speedometer. The GPS is accurate and easier to see when mounted on top of the dash anyway.
 
Thunderchief said:
I suspect I am not the only guy who has a Motorcycle with a speedometer that reads much higher than the speed /QUOTE]

Speedohealer as mentioned can be used to fix this but also affect the odo which is accurate.
Radar checks confirm it's not optimistic enough LOL.

The police model cluster can be set to 2mph or 2% I forget which.
Click to expand...
 
Last edited:
There are a number of speedohealer threads here, search for them. And at least a couple of posts describing replacing the standard speedo with one bought from a police bike (not a trivial task).

Last summer I checked my odo against the mile markers on the interstate. It was 3% high over a 10 mile stretch. I suspect that some of the difference is due to new vs. old tires, as well as brand. Never having collected a few samples of every tire used on ST's and mounted them, run them for a few miles, and then checked their circumference, I have to believe there is some tire to tire (brand) variation. And, I don't really know how indicated distance on brand new tires compares with old, worn out tires.

I'm in the process of installing a speedohealer, and I am not sure yet if I will zero the speedo perfectly or the odo. Final tweaks will have to wait for a 20 mile trip up the interstate to see what the odo does.
 
SMSW said:
I'm in the process of installing a speedohealer, and I am not sure yet if I will zero the speedo perfectly or the odo. Final tweaks will have to wait for a 20 mile trip up the interstate to see what the odo does.
Click to expand...

What is more important to you? Speed or miles traveled. I have one on my bike and installed one on the Son in laws. Both were off the same amount. About 7% on speed and 2% on miles. Corrected for speed as this is what was important to us. Both odometers are now 4% short. I just use a simple add 4 miles per hundred driven if calculating an accurate MPG. You can not have both speed and distance correct. I have checked mine using my gps and when to odometer shows 100 miles the GPS is 104 +/- a tenth or two.
 
Kevin_56 said:
What is more important to you? Speed or miles traveled. I have one on my bike and installed one on the Son in laws. Both were off the same amount. About 7% on speed and 2% on miles. Corrected for speed as this is what was important to us. Both odometers are now 4% short. I just use a simple add 4 miles per hundred driven if calculating an accurate MPG. You can not have both speed and distance correct. I have checked mine using my gps and when to odometer shows 100 miles the GPS is 104 +/- a tenth or two.
Click to expand...

Kevin,
You are right. I tend to cruise at speeds based on my gps, and use the speedo to maintain that speed (it is more visible especially in bright sunlight than the gps). And, truth be known, I lean toward having a speedo that is a tad optimistic - so it is my expectation that I will knock my speedo error down so the odo is spot on, and live with it showing 3% faster than actual speed.

I have noticed I can take the bike up to a steady speed, roll off on the throttle a little, and my gps instantly shows a slight drop in speed, but the speedo needle lags or even stays where it was (I'm talking about maybe a 2 or 3 drop in mph). The speedo eventually catches up (or down) but I think the analog display is not as responsive as a digital display would be.
 
This gets kicked around every now and then.

I solved it by putting a Cop speedo on my 2010 and I have one on my Project bike. Which leaves my Commuter bike with a stock speedo, which will probably get me into trouble because I forget I'm on the 2010 and when I'm doing indicated 80mph, I'm not doing my normal 73/74mph like I would be on the commuter bike! :eek:4:
 
I just add 5 to speed limit and go with it. if the speed limit is 65, I figure i'm safe running 70 on the ST. On my CB 1100, it is pretty much right on

My brothers Triumph and Yamaha both have speedo errors as well

It is a common problem on most motorcycles, or else Speedo Healer would have trouble staying in business if only the ST had this speedo error.
 
the Ferret said:
I just add 5 to speed limit and go with it. if the speed limit is 65, I figure i'm safe running 70 on the ST. On my CB 1100, it is pretty much right on

My brothers Triumph and Yamaha both have speedo errors as well

It is a common problem on most motorcycles, or else Speedo Healer would have trouble staying in business if only the ST had this speedo error.
Click to expand...

Agreed. My ST was off by quite a bit (don't recall the exact figure at the moment). My current bike, Tiger 1200 is also off, although it's got the least variance of all my bikes indicating 126KPH to an actual of 120KPH. Every bike I've ridden has been off to some extent, as have all my cars except for my Hyundai Elantra. Years ago, I even took my VW Jetta in to the dealership because it was off by 10KPH at 120KPH. Dealer said it was within normal limits. That's when I learned they're all off.

I've always tested using a GPS and have simply adjusted in my head for the variance so as not to get into trouble with LEO's. Was never keen on spending the $ for a speedo healer myself.
 
My 2009 was off by 6%. I added the speedohealer and it is spot on to 80, then off by about 1 mph above that. The odomoter is off by about 5% (low) but I'd rather have the speedo accurate and live with the low odo. It also messes with the miles per gallon meter but again, I add about 5-6% for that too when I look at it.

Scott
 
My bike's speedo is off as well and really it is unusual for me to try to maintain an exact speed, mostly the speedo is just to make sure I am not in danger of getting ticketed for which it is close enough for especially knowing that there is a 5% per cent safety cushion built in. Most of the time I just use the surrounding traffic as a a guide to my throttle input. Like most other riders I like to go just a little faster than the flow of traffic.

Gerhard
 
jfheath said:
Unless you use your satnav. But of course, these are not accurate all of the time. Depending on the view of the sky, the presence of buildings, trees, articulated lorries, whether or not you have been accelerating or decelerating,....... the speed shown on the satnav at any single point in time could be wrong.
Click to expand...

So are you TomTom lied to me when it said my VW Jetta went 340 km/h? They changed a road which was not reflected on the map and it gave me this bogus value a few years ago.

Gerhard
 
Many people report that every motorcycle that they have ever owned has speedometer errors. Many report the same with their cars/trucks. I must be unusually fortunate in that the speedometer in every single vehicle that I have owned has been accurate to as close as I can tell by eye while driving- they were all needle speedos as I have never had a digital sppedo. Every one read the same speed as those roadside radar things the police set up and were also accurate when compared to my GPS. This includes both of the ST1100's that I have owned. It also includes the two cars that I currently have. The only vehicle that I have ever had that is off by enough to tell by eye while driving is my ST1300- about 8%. When I discovered this I was rather irritated about it because of my past experiences and was about to bring it in for repair under warranty until I read here that this is "normal". Is my history with other vehicles really the anomaly and these speedo variances are "normal" and "acceptable".
 
I've been contemplating making note of the speedo reading at speeds between 30 and 100 mph., reconciling those indications with what appears on a GPS, and placing small labels on the speedo bezel showing actual GPS-confirmed speeds in 5 or 10 mph. increments. I just need to find a label maker that:

A - makes labels that are small enough & reasonably attractive (or at least not ugly) and,
B - the label material is durable for the application (weather/sunlight/washing resistance).

If anyone knows of such a labeling device, perhaps a reply via PM or new thread (to keep from hijacking this one) is in order.

Good Ridin'
slmjim
 
Last edited:
slmjim..I keep a piece of paper in the mapcase of my tankbag with the correct readings on it, but honestly I never look at it, I just go +5. From memory on my bike I know 55 actual is 62 indicated and 60 actual is 66 indicated
 
jfheath said:
So am I ?? That is exactly the point I am making - depending on the situation, they (the satnavs) could be wrong - and often are. Its interesting to see what it does in a tunnel. Enter it at one speed, and then slow down. Mine continues to show my entry speed until I emerge into daylight. Then it reports a ridiculous number of mph as it catches up with itself.

A lesser but similar effect can be observed along a tree lined route. Similarly when you go off the plotted route and it assumes you are still on the route it thought you should be on (as in your case).

I'm interested in your incident though. Did you have a route plotted at the time, or did it just assume that you were on one of the roads that it knew about ?
Click to expand...
GPS errors do occur but they average out given enough distance traveled and time. The few outliers of reported supersonic speed are lost on a bell curve. Most update about 60 times a minute and current models typically give a position within 1.5 meters of actual position during over 95% of data points. For checking actual speed against the speedometer avoid tunnels and canopied tree-lined roads and it will show tremendous accuracy. GPS was developed for and is used to land aircraft in zero visibility which requires placing a fast moving object at a precise location within 3 dimensions with something like 3 meter accuracy 100% of the time. It's more than up to the task of checking a car or motorcycle speedometer and odometer if you use it with a clear view of the sky.

I don't know about US law but all my cars I've observed with GPS, except for one, were observed to be within 1 mph at legal speeds but my motorcycles were usually off a few percent higher than actual with a few exceptions...My 2012 NC700X was within 1 mph up to 60 mph and only off more than 1 over about 100 mph. My BMW R100 was off less than 1 to 60 mph and my scooter is not off even 1 mph - but it only goes up to 42 mph. My Tiger is off about the same 7%.
 
Last edited:
I'm experimenting with building a speedometer that uses Doppler shift to measure the motorcycle speed. I got interested in this for two reasons. 1) I wanted to have a remotely located speedometer that I could put higher up in my field of view so I didn't have to look down so much and 2) I've always wanted to experiment with Doppler radar.

I just built a GPS speedometer with a 4 digit seven segment display. It's working very well. It does 10hz updates so I get to see updates to my speed in real time. As soon as I let go of the throttle, I can see the speed start to decrease with minimal lag. I thought doing a Doppler shift version would be fun to experiment with.

I've only put this in my car for the moment. I have to make a good case for the GPS version before I mount it to the ST.

Anyway, just wanted to share.

My ST speedo is off by a few mph compared with the Garmin readout which is slightly noticeable above 40mph.

Joel
 
You must log in or register to reply here.
Back
Top Bottom