Milage trip meter seems way out

[PhilJones 5]

Hi All,

I'm on my second week of owning an NC manual 750x 2014 and I'm using it for a 100mile round trip commute every day. I have already covered 1500 miles,  My problem is related to the trip meter saying I have completed 58miles when it is closer to 48 miles, this is almost backed up be the speedo showing 37mph when I am doing no more than 30. I am sure distance must be related to speed. This is in turn giving me a completely false mpg. This morning I clocked 216 miles on a 10.65L fill up that's 91to the gallon. I do ride within all the speed limits but still its just too good to be true!

Did the other people with faulty speedos have extended miles on the trip meter? Is there anything I can do to get more accurate readings. I checked the rear cog and it is 43 teeth so seems correct for the bike. 

[Mikdent 4,070]

Hi Phil and welcome along.  

 

Ive heard of the A trip messing about but never the actual speedo readout.

 

My A trip used to mess about and I read the solution was to make sure the HISS light is set to on (i.e. Flashing when the bike has been left along for short time).

 

Others have poo pooed the idea but it's worked for me and I didn't have the dash replaced either as I wanted to see the true mileage of the bike. 

 

But....as I said, Ive never heard of the actual speedo showing a false speed. 

[shiggsy 529]

I know there are some case where the bike sometimes looses battery power for an instance, and the cluster re-sets making it look like the trips in-accurate, but again not heard of the speedo being out like that?

[Tonyj 6,907]

Just an odd thought,  if it's overeading on the miles covered etc could it be a sprocket ( wrong one been replaced )  or sensor pick up in relation to the distance / revolutions turned like when you have bigger wheels on a car or maybe just a dodgy speedo . 

[PhilJones 5]

Hi Guys 

Mikdent I will keep an eye out for your suggestion I was tailing another NC on the way home and his speedo was 27 and mine 34 I just thought they might be linked thinking it was travelling further in a certain time would increase the presumed speed but that isnt very electronic   Tony J I checked the rear sprocket and it seemed to be correct. I might try to see if Trip B gives the same mileage or just clock the main tacco. Thanks all Phil BTW what a fabulous bike they are, I also have a 1995 speed triple for fun, but this is the master commuter.  

[embee 7,288]

Two possibles spring to mind.

If someone fitted a 16T gearbox sprocket from a 700 on your 750, which should have a 17T, then the gearbox will be running 17/16 times as fast as it should. The speedo is taken off the gearbox shaft so will show a higher value than the bike is actually doing.

The other one is that if yours has had the instrument pack recall change done and a DCT item is fitted instead of a manual (if this will actually work, I have no idea, just thinking aloud), then it would be a similar issue with the speedo calibrated for a 17/39 ratio and getting a 17/43, i.e. getting a faster signal than the bike is actually doing.

[PhilJones 5]

Hi NC Guru,

These two scenarios work well, I will have a look under the gearbox cover when it stops raining in London probably tomorrow   as for the instrument from the dct model I guess it will need to be checked by a dealer!  I usually avoid Metropolis like the plague  if I can... Thanks for your reply. P

[Tonyj 6,907]

Dct check is easy , they did it the other way on me and no handbrake symbol on the dash when brake activated . So they must different. Check the panel for the symbol and I was referring to gearbox sprocket , I should have been clearer .

[stephenmcg 869]

Check you are on miles and not Km

just a thought

smcg in roasting Glasgow - makes a change

[XXX 2,697]

When I ride with my GPS there is always a difference in speed between the bike's speedometer and the speed shown on the screen of my TomTom 450. I have assumed that the GPS is more likely to show an accurate speed (don't ask me why, just a gut feeling), which suggests that the speedometer overstates the speed by anywhere from 3-10kph, depending on how fast I am travelling. Top speed I have done is 130kph, yet there were still cars passing me, suggesting I was riding closer to the speed limit of 120kph. When I took a spin on my father in law's VFR 1200 there was the same gap between his speedometer and his GPS. 

[Bigglesaircraft 293]

If my maths are Ok the sprocket etc would have to be vastly different as the suggestions so far would not give such large changes, my suggestion go to a trusted shop with a recommended mechanic.

[Bigglesaircraft 293]

42 minutes ago, Woody 99 said:

When I ride with my GPS there is always a difference in speed between the bike's speedometer and the speed shown on the screen of my TomTom 450. I have assumed that the GPS is more likely to show an accurate speed (don't ask me why, just a gut feeling), which suggests that the speedometer overstates the speed by anywhere from 3-10kph, depending on how fast I am travelling. Top speed I have done is 130kph, yet there were still cars passing me, suggesting I was riding closer to the speed limit of 120kph. When I took a spin on my father in law's VFR 1200 there was the same gap between his speedometer and his GPS. 

In all the reviews that I have read since 2013 it has always been reported that the Speedo is very accurate with no deviation.

[XXX 2,697]

1 hour ago, Bigglesaircraft said:

In all the reviews that I have read since 2013 it has always been reported that the Speedo is very accurate with no deviation.

I've done some quick, non scientific googling on this and find nothing to substantiate that there is no deviation on a motorbike speedo. On the contrary, there seems to be a lot of sources suggesting the opposite. There does seem to be a lot of evidence, however, to suggest that GPS measurement is accurate, so I tend to think that my experience is probably correct. 

[Bigglesaircraft 293]

Back to a good, trusted and recommended mechanic then, problem solved!

[ChrisCB 6,674]

UK law is based on EU standard, a speedo must never show less than the actual speed or more than 110% of actual speed +6.2mph so legally could read 50.25 at 40mph. Manufacturers calculate in to read high so they never read less when you take in rolling diameter changes to tyres from tyre pressures, wear and different manufacturers from OE tyres. Satellite navigation is not the device designated by which the vehicle speed is measured so none of those factors are relevant. Navigation is not very accurate at the build up speed but a lot closer when cruising at a constant.

[XXX 2,697]

I think you're right about "speed build up". Changing speeds on the GPS seem to be a bit jerky but cruising seems to be accurate. 

[PhilJones 5]

On ‎09‎/‎08‎/‎2017 at 21:19, Tonyj said:

Dct check is easy , they did it the other way on me and no handbrake symbol on the dash when brake activated . So they must different. Check the panel for the symbol and I was referring to gearbox sprocket , I should have been clearer . Hi,  I do have a parking symbol on the dash next to the left hand indicator arrow but it doesn't light up at all. Does this symbol only appear on the Auto models? If so you have cracked it !!  

 

 

On ‎09‎/‎08‎/‎2017 at 22:40, stephenmcg said:

Check you are on miles and not Km

just a thought

smcg in roasting Glasgow - makes a change

 

[PhilJones 5]

1 minute ago, PhilJones said:

I am struggling with how to reply to individuals, I am definitely going to struggle with my bike fix   Anyway the auto  Dashboard is interesting, I have a parking symbol that seems to have no function (and does not light up ever) on my bike as it is a manual. Does this prove I have a DCT instrument panel on a standard X

 

 

[SteveThackery 3,090]

Earlier you said your speedo reports 34mph when you colleague's reports 27mph.  That's a ratio of 1.26 : 1.  Not enough to be explained by an mph/kph error, but too big to be explained by a one-tooth difference on the sprocket.

 

On the other hand, your 27mph/34mph readings might be inaccurate because it's very difficult to track someone at exactly the same speed they are doing, all the time.  Even so, I am puzzled by this.

 

I hope someone with a manual will chime in to answer your question.  Mine's a DCT, and I don't know whether the manual bikes have the same panel fitted with an inoperative warning light, or a different panel.

[Tonyj 6,907]

Steve when my dash (2015 dct )was changed they put one on that worked but no parking brake symbol would show when brake activated 

so it had to be returned and replaced by another dash. I did ask if it's just a wire etc but was told they are different ?

[SteveThackery 3,090]

2 hours ago, Tonyj said:

Steve when my dash (2015 dct )was changed they put one on that worked but no parking brake symbol would show when brake activated 

so it had to be returned and replaced by another dash. I did ask if it's just a wire etc but was told they are different ?

 

Ah, OK - that does sound like they are different, then.  Cheers, mate.

 

We aren't making much progress towards solving the riddle, though, are we?  Except that we have established it has the wrong dash fitted.  Phil: at this stage my advice would be to get the dealer to fit the correct dash before pursuing any other leads.  If it's still mis-reading after that, we can have another discussion session on it.

[Rogue 831]

On 07/08/2017 at 22:29, embee said:

Two possibles spring to mind.

If someone fitted a 16T gearbox sprocket from a 700 on your 750, which should have a 17T, then the gearbox will be running 17/16 times as fast as it should. The speedo is taken off the gearbox shaft so will show a higher value than the bike is actually doing.

The other one is that if yours has had the instrument pack recall change done and a DCT item is fitted instead of a manual (if this will actually work, I have no idea, just thinking aloud), then it would be a similar issue with the speedo calibrated for a 17/39 ratio and getting a 17/43, i.e. getting a faster signal than the bike is actually doing.

I have same model (2014 manual 750x) and as Embee has suggested I suspect that issue with inaccurate mileage reported on trip meter could well be related to sprocket that is fitted. 

A couple of years ago I needed new chain and sprockets and correct sprocket was in very short supply in UK at the time so I suspect the dealer fitted the "alternative" sprocket. 

I pretty much only use bike for daily commute and my regular 3 day mileage total between re-fuelling went form being 180 miles prior new sprockets to 191 with new sprocket (fits in with Embees' mathematics). Now following another new set of sprockets & chain last year it's back to showing correct 180 miles

[SteveThackery 3,090]

7 hours ago, Rogue said:

I have same model (2014 manual 750x) and as Embee has suggested I suspect that issue with inaccurate mileage reported on trip meter could well be related to sprocket that is fitted. 

A couple of years ago I needed new chain and sprockets and correct sprocket was in very short supply in UK at the time so I suspect the dealer fitted the "alternative" sprocket. 

I pretty much only use bike for daily commute and my regular 3 day mileage total between re-fuelling went form being 180 miles prior new sprockets to 191 with new sprocket (fits in with Embees' mathematics). Now following another new set of sprockets & chain last year it's back to showing correct 180 miles

 

Yeah, that's also something that should be put right.

The reason I'm uncertain about it is that the error (as reported by Phil) is too big (much bigger than 17/16) to be explained by an incorrect sprocket.  Of course, it may be that Phil wasn't able to get an accurate figure for the speedo error.

[DaveM59 1,605]

Does anyone have an accurate list of what sprockets front and rear each model should be fitted with? Models and years.

My Integra over reads speed by 3 at 30 to 7 at 80 according to my GPS and it had new C&S when I got it so I'd like to check too.

[embee 7,288]

5 minutes ago, DaveM59 said:

Does anyone have an accurate list of what sprockets front and rear each model should be fitted with? Models and years.

My Integra over reads speed by 3 at 30 to 7 at 80 according to my GPS and it had new C&S when I got it so I'd like to check too.

That degree of over-reading is correct.

You can check the sprockets/chain details on https://www.bike-parts-honda.com/ . I think it's also in the owner's manual, may be wrong on that.