Speedo inaccurate?

[motoinmoab]

Can you guys with a GPS please verify what I'm thinking:  The DRZ-S speedo is reading fast, like maybe +5 mph at 55?  I live in the boonies with no mile markers or radar signs so I can only go by how traffic wants to pass me when I'm going the speed limit @ 55mph.

 

I had a TrailTech Vapor on my '05 E and you dial that in at setup.  This factory unit seems very optimistic. 

[Supermotomad1]

Can you guys with a GPS please verify what I'm thinking: The DRZ-S speedo is reading fast, like maybe +5 mph at 55? I live in the boonies with no mile markers or radar signs so I can only go by how traffic wants to pass me when I'm going the speed limit @ 55mph.

I had a TrailTech Vapor on my '05 E and you dial that in at setup. This factory unit seems very optimistic.

no speedo or even rev counters are 100%

[mickeydee]

Stock speedo is generous 5 to 7% on average

[Kioti]

This factory unit seems very optimistic. 

I would like to know how optimistic the DRZ speedo is also.

 

My 650 Burgman is 9.5 % optimistic, but pretty easy to figure the speed. 55 indicated is actual 50, 77 is 70 .

[JoeMongo]

Yeah, mine was off by a lot as well.  Funny thing though, the trip odo was dead nuts on, as long as I left the calibration scale at 100 percent.  When I took it apart a few weeks ago (after it died), I found that the speedo cable direct drives a pulse tachometer wheel with four nice large windows for the infrared LED to shine through to a discrete photo eye to count pulses.  Therefore, the only inaccuracy in the system (other than tire circumference differences) was the lousy clock.  If they had put a decent clock in there, it would have been as perfect as the trip odometer.

 

My DRZ OEM trip odometer typically agreed with my Garmin 62S within one or two tenths of a mile, at the end of long days on the trail OR on the road.,  Unbelievable, except that I saw it each day.

 

Tire choice also makes a big impact.

[William1]

Depending on tire choice, the OEM odometer is fairly accurate (and has to be, by federal law). The speed part however, is about 10% high. Which is fairly common. I think it has something to do with the 'bold new graphics'.

[Zeeno]

I'm sure they intentionally make the speedometer high for liability reasons. Like William said.

Any motorcycle I have ridden indicates speed ~5-10% higher than actual.

[taldrz]

GPS verified my stock speedo shows 60mph when I'm actually doing 55mph.

[motoinmoab]

Thanks guys.  I figured it had to be off by about 5 at 55 mph by the way cars keep passing me.  If it was off only 2 or 3 they probably would try to be patient.  So 60 is the new 55.

[BurnCycle]

I replaced my stock speedo a few years ago with a Vapor because it was so far off. By a whopping 30%. Once I did and got it all calibrated and checked it against my GPS unit it was very close. At least within a tenth of a mile. Way better than before. My reading for gas mileage were down to 33 mpg with the old one. Now I get between 45mpg highway and 55 offroad. Running at high speeds of 75mph on the highway sucks the gas down. Crossing the desert it does so much better cuz I usually cant or dont travel that fast.

[ohgood]

Thanks guys.  I figured it had to be off by about 5 at 55 mph by the way cars keep passing me.  If it was off only 2 or 3 they probably would try to be patient.  So 60 is the new 55.

 

 

keep in mind that every bike made reads high, same with cars, trucks, vans, etc

 

it's your 'wiggle' room for not getting a ticket. 

 

if you speed, and are caught speeding, the officer already knows:

 

1 your speedometer read higher than your speed

2 you disreguarded the higher speed reading, and continued

 

that's why they really don't care about excuses.

[Plane Dr]

Not all speedometers read high. My BMW is spot on.

[William1]

My Nissan Frontier and my wifes Volvo are within 1%. I find most four wheel vehicles are accurate and most Euro bikes accurate. It seems Japanese bikes are almost all off by 10%. Probably a translation thing.......