posted August 12, 2006 05:47 PM
Edited By: flyboy on 12 Aug 2006 19:54
Speedo Error I was curious about the accuracy of my speedometer so I set up my GPS on my bike.
As a pilot I have three Garmin GPS's and my portable is a Garmin 296 which runs about $1,600. It connects with 12 satellites so it is one of the most accurate GPS's made, if not the most accurate. It's also WASS capable. (means it's accurate)
posted August 12, 2006 06:04 PM
This is by design on all sport and many sport touring bikes. It is likely what you said...trying to limit their liability (speeding tickets). Every sport bike I ever had had this issue, except my FJR, which was off like 1.5%. 7-8% high is the norm for most of these types of bikes.
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FYYFF!!!
posted August 12, 2006 06:08 PM
Almost every bike I know has the speedo read high. Probably a legal thing. If they read low people would blame the mfg. for some of the more minor speeding tickets.
They also have to factor in the possibility of people fitting different brands of tires with small differences in diameter. Better to be on the conservative side and have them read high.
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Speed has never killed anyone,
suddenly becoming stationary...
That's what gets you.
posted August 13, 2006 05:56 AM
On the sprockets calculations page the bike will do 204 at 10800. This past weekend the bike was pulling to 11k. I made it to about 10800. My rear tire has wear on it. So i would say at least from 195. It took sometime but it kept pulling.
posted August 13, 2006 06:11 AM
195 indicated=180.375 true...on the 14, against a GPS. When they do top speed measurements, they are real speeds using radar, not indicated speeds on the speedo. Your bike will never do 195 without serious engine mods and a broken or patched speed limiter.
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FYYFF!!!
posted August 13, 2006 06:23 AM
FBA i the sph set at -20 so i cant tell what the speedo says. The bike has the usual mods so far besides nitrous and gearing. Im using the tach for a idea of the speed. The speed sprocket math calculation said 204 at 10800 rpm. I only said 195 because my tire is worn. Im sure that would be an under measurement. Besides the math calculations is what im going by. It seems that every gps is different but the math calculations always stay the same. With the mods and a lighter ride. The bike may have gotten to 11k alot faster.
posted August 13, 2006 02:38 PM
Best way to set your SH is to go buy a GPS and see the exact difference...once done, return the GPS for a refund... ____________
FYYFF!!!
posted August 13, 2006 11:48 PM
Further to this, fitted an 18t sprocket last week and now the speedo is correct.
____________
Candy Thunder Blue 2006 ZZR1400
Stock wheelbase
Max: 205.4 mph in 1.25 miles
2012 ZZR1400 in Golden Blazed Green
Brock CT Full System. etc
Max: 203.1 in 1 mile (so far)
Needs a life
Full throttle!
Posts: One MEEEEEELLION
posted August 14, 2006 01:31 AM
quote:Best way to set your SH is to go buy a GPS and see the exact difference...once done, return the GPS for a refund...
Not only is that consumer fraud, but it's not the best way. Best way is to put the bike on a dyno. Run it at whatever your normal cruising speed is (140kph, whatever) as indicated on the dyno, then set the speedohealer appropriately. Run it up to speed again to verify and you are done.
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82 Gpz750, 84 Ninja 900, 2000 ZX12R (Muzzy Big Bore Kit), *another* 2000 ZX12R (Muzzy custom stroke crank 1341cc motor), 2004 ZZR1200, 2005 ZX10R, 2007 ZX14, 2008 Concours 14, 2014 Versys 650, 2014 Yamaha WR450F, 2015 Ninja H2
quote:Best way to set your SH is to go buy a GPS and see the exact difference...once done, return the GPS for a refund...
Not only is that consumer fraud, but it's not the best way. Best way is to put the bike on a dyno. Run it at whatever your normal cruising speed is (140kph, whatever) as indicated on the dyno, then set the speedohealer appropriately. Run it up to speed again to verify and you are done.
Sorry dude...but all major electronics retailers including Costco (who is a large GPS reseller), have a no questions asked, 30-day money back guarantee. I am a large GPS distributor and I deal with all of them. This 30-day guarantee exists in the US and Canada. We get units back from people who buy them for a trip and return them...no questions asked. There's no fraud there at all.
2) Dyno...it won't account for wheel slippage
3) GPS is way more accurate than you think, especially when compared to a Dyno. Even the consumer GPS units are accurate on speed to less than .01%
4) Best to use tools that will reflect real road use...not test Dyno's IMO.
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FYYFF!!!
posted August 14, 2006 10:54 PM
Yes GPS are very accurate in measuring speed and You should also remember that the postion accurance the GPS shows has next to nothing to do with the speed accurancy because the speed is not calculated from the positon but on a different method wich is very accurate even if don't have many satellites showing.
posted March 26, 2007 09:52 PM
since using my GPS a few days, I can not beleive the amount of speedo error Kawi provided me!
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2010 Concours14
'08 R1 YAMAHA
ZX14 gone!
CBR600RR track bike
Needs a life
Full throttle!
Posts: One MEEEEEELLION
posted March 27, 2007 08:43 AM
It's not the accuracy of the GPS I'm talking about, it's the slew rate. It can't measure speed instantaniously, so there is always an inherent lag. And with regard to tire slippage on the dyno, there is zero if you are just holding steady speed. Tire slippage occurs during accelleration runs, not zero-load steady state running.
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82 Gpz750, 84 Ninja 900, 2000 ZX12R (Muzzy Big Bore Kit), *another* 2000 ZX12R (Muzzy custom stroke crank 1341cc motor), 2004 ZZR1200, 2005 ZX10R, 2007 ZX14, 2008 Concours 14, 2014 Versys 650, 2014 Yamaha WR450F, 2015 Ninja H2
quote:who looks at the speedo anyway? I just ride off the tacho. Yellow box fixes speedo error.
I suppose you know the tacho is optimistic by several percent too.
____________
Candy Thunder Blue 2006 ZZR1400
Stock wheelbase
Max: 205.4 mph in 1.25 miles
2012 ZZR1400 in Golden Blazed Green
Brock CT Full System. etc
Max: 203.1 in 1 mile (so far)
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posted August 12, 2006 05:47 PM
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