signifigant speedo error?

[kennedyted]

i have noticed riding on the highway my speedo is off, it would always be 90 or so but barely passing people, my brother rode my bike to brampton canada and hit some work zone readouts, only one he remembers clearly was speedo-37 wokzonereadout-31 he hit one in canada but doesnt remember exactly , he said was around 20-25 kmh off....as far as i know the bike has the stock sprockets, why would it be off so much

 

[mave2911]

The stock speedo is out by approximately 7%.

Cheers,
Rick

 

[kennedyted]

i was reading a post about speedo drd or whatever( alt to speedohealer), will this fix the inaccuracies , or would i be better off go up/down 1 on my sprocket seeing how its cheaper? also my math be wrong but it comes out to like 20 percent off if it reads 37 and im going 31, that seems like alot to me

 

[outasight20]

i was reading a post about speedo drd or whatever( alt to speedohealer), will this fix the inaccuracies , or would i be better off go up/down 1 on my sprocket seeing how its cheaper? also my math be wrong but it comes out to like 20 percent off if it reads 37 and im going 31, that seems like alot to me

Stock speedo error is ~7% as mave said. If you want to nearly eliminate speedo error, switch to a 17T (+1) front sprocket for a speedo error of under 1% at all speeds. I have the 17T sprocket and enjoy the accurate speedometer on my highway commute.

 

[Lefty]

Stock speedo error is ~7% as mave said. If you want to nearly eliminate speedo error, switch to a 17T (+1) front sprocket for a speedo error of under 1% at all speeds. I have the 17T sprocket and enjoy the accurate speedometer on my highway commute.

I too switched to a 17T in the front and on a long 2600 mile ride using a GPS I found my speedo now to be spot on accuracy wise but my odometer was now
-4% off.

 

[GTPAddict]

I have the SpeedoDRD on mine with stock gears. Adjusting to 7.7%, the speedo is correct with the GPS all the way up to 90MPH (didn't check it any faster then that), but the odometer is off by 7.7% now. They build the 7ish% error in to the speedo. I believe they do it to make you go slower (pretty good idea if you ask me).

 

[Signal 50]

I have tracked my speed with GPS and the speedo next to each other. Stock gearing my speedo reads 4mph over actual speed.

 

[TownsendsFJR1300]

Stock, at approx 60 MPH, mine read low 3-4 MPH.

A Speedohealer, adjusted to match the GPS, fixed it dead on....

They also make a plug and play so NO hacking into the wiring assembly is required...

You can remove it if you get rid of the bike as well and use it on another bike...

 

[kennedyted]

i get that they are off stock but at 37 being 31 thats almost 20 percent off, could there be a problem elsewhere causing the bigger discrepancie, like i said rear sprocket is stock, how do i tell if front has been changed ? thats all i can think of as to why so large a difference

 

[mave2911]

i get that they are off stock but at 37 being 31 thats almost 20 percent off, could there be a problem elsewhere causing the bigger discrepancie

Possibly - but I'd check my speedo vs GPS first, as the roadside speed indicator may have been reading incorrectly.

I purchased a phone holder for bicycles/motorbikes that I put on the bar, loaded the phone up with a GPS speedo and got my accuracy that way.

Maybe you could do similar, or ride with a pillion and get them to hold the phone.

I'd be very surprised to see it was 20% out, more likely 7%.

Judging speedo error based on traffic is also an incredibly inaccurate way of determining the error margin.

THEIR speedos are out too! (as from the factory, so everyone tries to compensate etc)

Test it with a GPS speedo, and see.

Cheers,
Rick

 

[kennedyted]

u recommend a gps holder?

 

[mave2911]

I bought a cheap phone holder for bicycles/motorbikes on eBay.

Cost like $5 and mounts on the bars between the fixture bolts (the '05 doesn't have that Yamaha plate)

Mount your phone in there and download an appropriate app.

Cheers,
Rick

 

[GTPAddict]

I've got 2 bar mounts for my Garmin GPS, both from ebay and both were really cheap.

Heres one
MOTORCYCLE/BIKE HANDLEBAR MOUNT HOLDER GARMIN NUVI GPS | eBay

Couldn't find the other, but I was riding with a guy one time that had the suction cup attached to the tank. This seemed to work really well. I mounted my GoPro like that one day and it worked fine. Most GPSs come with a suction cup mount, so you may not have to buy anything.

 

[TownsendsFJR1300]

i get that they are off stock but at 37 being 31 thats almost 20 percent off, could there be a problem elsewhere causing the bigger discrepancie, like i said rear sprocket is stock, how do i tell if front has been changed ? thats all i can think of as to why so large a difference

There's 3 bolts (allan head) that hold the sprocket cover on. You don't have to remove the shifter rod if you gently remove the cover. When re-installing, make sure YOU DON'T PINCH the TWO wires running down the left side cover. Once the covers off, you can see the front sprocket and count the teeth.

From what you describe, the front sprocket has been changed to a smaller one than stock, The stock Yamaha sprocket has a "plastic like" center (which I think helps with noise/vibration). An aftermarket sprocket won't have this plastic.

The below pic is that of an aftermarket sprocket

 

[kennedyted]

duh i didnt even think of the suction cup that came with gps lol good call, thanks fjr gonna check it out as soon as my little brother gets my bike back from canada