2013 FJR Digital Speedometer Accuracy

[art miller]

I have a set of PR2's ready to mount when the original tires are shot. The rear will be a 190/55-17. Considering the Traction Control feature, will going with the larger rear tire have any negative affect on TC? I read comments claiming the 190/55 puts the speedo almost dead-on with GPS.

 

[Dale2010]

I have a set of PR2's ready to mount when the original tires are shot. The rear will be a 190/55-17. Considering the Traction Control feature, will going with the larger rear tire have any negative affect on TC? I read comments claiming the 190/55 puts the speedo almost dead-on with GPS.

Let us know how you make out with the new rubber.

How about the handling?

Also, does it really improve speedometer accuracy as it's the pits with the standard Bridgestone 023s as shipped.

 

[steve_g]

I have a set of PR2's ready to mount when the original tires are shot. The rear will be a 190/55-17. Considering the Traction Control feature, will going with the larger rear tire have any negative affect on TC? I read comments claiming the 190/55 puts the speedo almost dead-on with GPS.

Art,

I read of others using a 190 on a 2013 fjr and don't recall any issues including TC. If you do a search, I think fairlaner was one of the first.

 

[art miller]

Steve, I read Richard's thread on the use of 190's. He did not have any negative comments. He said the 190 made getting the bike on the center stand easier. I find the 14ES much easier to get on the center stand compared to my 07. Hopefully since no one has yet found any negative input to TC it is good to go with the bigger tire.

 

[kebo123]

My friend imported this week AE '14 RED one from NA to Europe (he loves red and with el. suspension red is not available in Europe at all). We have been together in Austria this weekend for riding academy organized by Austrian cops. Actually - the red one on his FJR is 100% identical to my wifes '08 Yamaha XJ6 diversion...

Back to the topic: He was very happy to learn that speedo on his bike is possible to set from M/H to km/h. (actually we tried to change temp from Fahrenheit to Celsius but without success - any suggestions welcome) By riding on highway next to each other with switched NAVI on my bikes my bike ('13 European A version) showed 120 km/h, his bike ('14 AE NA version) displayed 112km/h and Navigator (BMW NAV5) 112 km/h. So you guys in NA has really accurate speedometer on FJR - at least on '14 models, ours show 8-10 km/h more than in reality is.

Some pictures from the event here - last one is not is good quality, but red FJR in action looks great:

 

[CA G-Man]

I just got a TomTom Rider and so for the first time have had a chance to compare my 2013's speedo to GPS. I knew the speedo read high, but I was pretty surprised how high. I haven't crunched the numbers to work out the exact percentage of error, but it looks like it reads about 12-13% higher than actual (112 kph on bike = 100 kph on GPS). I guess with new tires that would drop a bit, but probably not too much (my original BT023s with 8700 km on them aren't too thin yet!).

I'm not terribly concerned, but I might feel a little ripped off if someday I'm selling a bike showing 112,000 km when it really only has 100,000.

 

[Bungie]

Mine was off a similar amount (I think about 8-9%) with the stock tires. BTW, I just changed mine at 13,000km. Pretty good! About 8000 miles.

Anyway, put on a set of PR4's that are a bit taller than the stockers. Dropped it down to about a 5% error.

Oh ya, just because the speedometer is off doesn't mean your odometer is off a similar amount. In fact, I believe their are laws regarding that. But I haven't checked it.

 

[Allen_C]

These posts are very odd to me. At an indicated 40 my TomTom Rider states 39, at indicated 75 it's 73, at 130 it's 126-127. These are all mph. Initially, I thought it was a USA vs other country's bikes but I'm only experiencing about a 2.6% difference, not 9%!

 

[Old Guy]

I've not checked mine against a GPS, but I've checked it against mile markers over a 10-mile stretch of freeway a couple of times with a stop watch, and I think it's within 1 or 2 percent in MPH. It seems the people reporting wide variances are in KPH. I can't see how it'd matter, though. I'd guess that the computer basically counts the revolutions on the rear tire over some period of time and uses the circumference of the tire to computer speed. Whether that's in KPH or MPH shouldn't matter.

 

[CA G-Man]

Yeah, I wondered about the link between the speedo and the odometer. I would think that since they're just different calculations based on the same raw data (the number of turns of the wheel, the wheel diameter, and in the case of the speedo, a clock) they'd be off by the same percentage. Given that the displayed clock seems to keep good time I don't imagine that could be the issue. I haven't done the math on the actual effect of tire wear, but I suppose that could account for most of it (I'll have to watch for the change when I put new rubber on).

If anyone has actual knowledge about how these things work rather than just idle speculation like mine, I'd be interested to hear it.

 

[mcatrophy]

Yeah, I wondered about the link between the speedo and the odometer. I would think that since they're just different calculations based on the same raw data (the number of turns of the wheel, the wheel diameter, and in the case of the speedo, a clock) they'd be off by the same percentage. ...

As far as I can tell from my Tomtom and my (GenII) odometer, there's about the same error on distance and speed readings, a little over 3.5%. I've found this on many occasions, so I believe the bike's speedometer and odometer are consistent with each other.

 

[Queensland Ken]

Not quite %10 error on my 2014 AEE, 8-10 km/h.

 

[Just Krusen]

My bike at 82 shows 80 mph on the gps. I checked the odometer when the bike was new and it was almost spot on to the gps over 100 miles. It's the closest any of my vehicles have ever been. I prefer the odometer to be more accurate than the speedo and mine is.

 

[RichDoyle]

One question emerges from these similar experiences: why hasn't Yamaha corrected this with the (their) suggested tire sizing long before the bike gets to market? Most automobile owners wouldn't accept this discrepancy (nor would the police if the readings were low) so why should bike riders be any different? Just wondering...

Both my car and my truck show just about the same discrepancy as my FJR.

 

[RichDoyle]

I sense a conspiracy here. Note that all the places that have the Queen of England on their currency seem to have this problem.

 

[Bungie]

I sense a conspiracy here. Note that all the places that have the Queen of England on their currency seem to have this problem.

Yup, I noticed that a while ago. It seems the math routines when converting to km/h are suspect.

Mine was off a similar amount. Put on a fresh set of PR4's (slightly taller than the stockers) and am now out only about 5% (haven't checked beyond casual comparison).

 

[ionbeam]

The Gen I used a VSS (vehicle speed sensor) to derive speed/distance because ABS wasn't available on the USA '03 and optional on the '04 & '05. The Gen II & Gen III use an ABS wheel sensor for the speed/distance source. The ABS ECU needs to very accurately know the wheel speed to calculate the slip angle of the wheel and determine if the wheel is impending lockup. In the later Gen's the ABS ECU feeds the engine management ECU the wheel speed info.

What the speedometer and odometer reads is determined by Yamaha's wishes and the accuracy of the servo that drives the speedometer's needle. The ECU(s) are more than capable of calculating speed to better than ± 1 mph. As previously mentioned, the tire diameter will play a role in both speed and distance readings.

On the bright side the error is consistent; just think if it varied during the day or from day to day.... The worriers on this site would never be able to sleep at night or ride during the day because calculating gas mileage and fuel volume to empty would really be an unknown.

 

[Brodie]

Nobody mentioned what type of road they were on when they took their percentage measurements.

Was the road curvy or straight?

Your best measurements will be on a dead straight road most likely found out here in the western states. When the bike is leaned over the effective tire diameters are smaller due to the rounded profile cross section of the tire. Dark siders also will experience this, however the effect will be less due to the squarish nature of the tire. Sidewall deflection has a play here.

Your GPS also will be affected by the number and severity of the turns. It has to do with sample rate. The more the road changes directions the more the samples will 'chord the turns'.

It's kinda like reading your airspeed and equating it to distance traveled. I think Yamaha has the system set up pretty close considering all the variables.

Of course, what do I know, I just ride the damn thing and take it for face value.

Brodie

;-)

 

[CA G-Man]

Brodie, around here a curve is something to dream of. To visualize. To anticipate. To salivate over. Not something to actually experience while riding more than once or twice in an afternoon.

Dead-straight roads, for the most part, and my speedo reads about 12% high.

 

[Allen_C]

Brodie, central Indiana is covered in long straight and boring roads! My observations were on straight flat interstates and state highways. I don't think I would even want to try to compare speedo to gps while leaned over in a curve...