2017 CB1100EX Speedometer error?

Thread starter
The ferret_imp said:
tuareg I have a good friend from Germany that comes to visit every once in awhile and he says he likes coming here because gas is on sale lol

3rd bike what speedo app did you download? to a smart phone?
Click to expand...
I believe it's just called 'speedometer', downloaded it to my iPhone SE. It has a built in 'alarm' that flashes and beeps when you pass your choice of speed limit. (Like I could hear that on the bike!) The app eats up battery when flashing and beeping, and the only way around that is to buy an upgrade. I really just got this app to check my speedos.. Now that I'm done, I'll prolly delete it.
 
The ferret_imp said:
tuareg I have a good friend from Germany that comes to visit every once in awhile and he says he likes coming here because gas is on sale lol

3rd bike what speedo app did you download? to a smart phone?
Click to expand...
Yeah, he's right... There are worse places though, for example I always drive through Italy non stop because even diesel is a whopping 6.5 US$/gal (gas is 7):D
 
After a 5 year relationship with my CB11 (2013 European model), regrettably I have decided that I need to move on with my 'modern ride'

Having reflashed the ECU, gutted the catalytic converter, fitted a Yoshimura RS3 muffler, a K & N air filter and upped the front sprocket to 19 teeth, today was the day to at last find out how fast she would go.

Not far from where I live there is a 1.5 mile straight beside a reservoir with no pavements (ie no pedestrians), no roads joining it, a sweeping bend at the top before a slight drop to the flat road and best of all no police! Back in the day this was where we tested the work done on our bikes.

A teenager once again I came around the the top left hander in 3rd at about 70 mph. As the straight opened up in front of me, for the first time ever I wrung its neck to the redline, before notching up into 4th. At the end of flat mile there is a slight incline before a sharpish right hander. Tucked in behind the Road Comet II (with the high aero screen) with the revs nudging 8k the speedo was showing somewhere between 125 - 130 mph (at that speed concentration is required elsewhere!)

Very satisfied with this result I rode back and did the same run again, this time clicking up into 5th, this whilst dropping the revs to nearer 7k little effect on the speed over this short distance.

Happy with my first bike speed trial in 35 years I checked the Tomtom - 119?

So a question - is my speedo over reading by 10 mph at that speed, or was the Tomtom unable to register accurately over such a short distance?

I have to say that I suspect speedo error, as it does over read, according to the GPS by about 5 mph at 'legal' speeds.


Sent from my GT-N7100 using Tapatalk
 
As I recall, back when the CB1100 was first released here in the States, road tests showed that the speedometer was surprisingly accurate. That would have been with a fairly fresh set of tires. As tires wear and become smaller, I would imagine that the speedometer reading would become a bit faster over time but I have no idea to what degree.
 
Guth_imp said:
As I recall, back when the CB1100 was first released here in the States, road tests showed that the speedometer was surprisingly accurate. That would have been with a fairly fresh set of tires. As tires wear and become smaller, I would imagine that the speedometer reading would become a bit faster over time but I have no idea to what degree.
Click to expand...
My 2014 standard has the most accurate speedo of any vehicle I have owned.

The speed sensor is on the rear.

If a new tire is 26" OD, the circumference would be 81.64" (pi x D)
If worn is 25.5", the circumference would be 80.07"

If 60 MPH is indicated with a new tire, then a worn tire (based upon 1/4" less tread on the radius) would indicate 58.84 MPH.

81.64/60 = 80.07/X

A new tire indication of 100 MPH, would be be 98.08 with a worn tire...again, that is based upon a 1/2" difference in diameter between new and old.

81.64/100 = 80.07/X

Not a big difference, about 2% regarding circumference, which is proportional to speed.
 
The rear tyre is the OEM Dunlop Sportsmax Touring 140/70 R18.
The tread at the edge measures 4.6mm and in the centre 3.7mm.
It has done 6k miles always at the correct pressure of 42psi.

Sent from my GT-N7100 using Tapatalk
Just a thought, but why did Honda change the speedo after the 2013 bikes? To those that only go up to 120 mph?

Sent from my GT-N7100 using Tapatalk
 
I've read on car forums mention of law in other countries that a car could not go faster than the dash indicated at any given speed so they default to slightly lower than displayed.

It is not uncommon for a car to read 3% higher than actual speed. Also explains why I remember being in cop cars and them having a sticker on the dash stating something like calibrated speedo.
 
PowerDubs_imp said:
I've read on car forums mention of law in other countries that a car could not go faster than the dash indicated at any given speed so they default to slightly lower than displayed.

It is not uncommon for a car to read 3% higher than actual speed. Also explains why I remember being in cop cars and them having a sticker on the dash stating something like calibrated speedo.
Click to expand...
I am not sure where you are coming from with this?

But I can tell you that here in the UK there is an allowance in the law for a speedometer to be 10% inaccurate ie you will not be prosecuted if you are doing 33mph in a 30 limit, 66mph in 60 or 77mph in a 70 etc etc.
Of course if you are traveling in/on a machine with a speedo that already overeads by 10% you've got a fair old calculation to make if you want to push the legal speed limits, when perhaps you should be concentrating on the road?
 
Dengie Boy, I haven't seen anyone respond to your question about the GPS. I'm sorry I can't help either, other than to say that my CB's speedo says I'm going faster than the GPS, but the GPS takes a while to react to any throttle variation, so I'm not sure how much you can rely on it.

At one point I had a iPhone app called "QMT" which allowed you to run a quarter mile and collected all sorts of data about the run. That might help.

However, the error you reported seemed excessive to me.

I suppose you could ask a friendly police officer to point a speed camera at you. :P
 
3rdbike_imp said:
I ran a search on this, found two threads with those words in the text, but the subject was how tire size might affect speedo reading.

My question is: has anybody determined if the 2017 EX speedometer is accurate? Reasons for asking: motorcycle speedometers have traditionally been 5 - 10% fast, and keeping up with traffic on I-40 (the freeway) here in Albuquerque, my speedo is reading 75 - 80 mph. The speed limit is 65mph. Am I naïve, and/or giving too much benefit of doubt to these cag(ahem) drivers? Or, is this simply the usual motorcycle speedo error?
Click to expand...

Hi. I just bought the 2017 EX two weeks ago. Last weekend I used a GPS speedometer app on my Android and found the accuracy to be very good/acceptable. Specifically, it was dead on until a little over 30 mph. When I got over that it looked like the speedometer on the bike was reading high by around 1 mph. When I got up to around 75 mph (per Android app) the speedometer on the bike read 76 to 77 mpH depending. I thought there would be more error than this so was quite pleased not to have to run out and buy/hook up one of those calbrating gizmos.
 
G'day 2017CB1100EX-STL. Welcome to the forum.
 
You must log in or register to reply here.

Similar threads

V
2017 CB1100 EX First Ride Review
5 6 7
Replies
137
Views
13K
riggies_imp
R
Back
Top