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Post by scooterdave on May 23, 2013 6:09:14 GMT -5
My 2012 Jonway yyt250 speedomoter doesn't seem to be accurate.
Has anyone else noticed this?
For instance when it says Im doing 40 MPH I believe im doing 35.
I live near a highway that is 55 MPH If i'm doing 50 MPH on my bike the cars are wizzing by me, going around me, honking at me.
So I believe I'm doing 45 in a 55 ?
Tires are origional, not been changed, only replaced valve cores.
Are cars and traffic just speeding? or is it my scooter?
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Post by larry001964 on May 23, 2013 6:44:51 GMT -5
Hi ScooterDave,
The Inaccuracy of Chinese speedometer have been the subject of many discussions on other forums, Including the old scootdawg. Yes they can be quite inaccurate. My suggestion is if you have a smart phone, there are gps apps that can be downloaded, you can use that to confirm the speed your traveling... It's not exact but other than marking out a mile, and timing the run, or driving besides a car with an accurate speedometer it will get you close to your true speed.. Good Luck
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Post by devo344a on May 23, 2013 8:26:49 GMT -5
What I do is drive down the road and if it will run 60mph check it with the mile marker
it should be a mile a minute
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Post by chihuahuas on May 23, 2013 10:10:03 GMT -5
seconds per mile / 3600= MPH
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Post by rollbar57 on May 28, 2013 18:19:55 GMT -5
got the same scoot I checked it this weekend speedo said  mph gps said 68 speedo is right up to 30 mph gps confirmed it but after that it seams like 1 mile for every 5 its off so I just keep up with traffic or other scoots I ride with lol most of them are 100 cc or less lol |
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Post by domindart on May 28, 2013 19:33:19 GMT -5
mine is 5 mph off (speedo too fast) too
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Post by prodigit on May 28, 2013 19:55:31 GMT -5
Best thing I'd advise, is get a GPS, ride at a constant speed (eg:30MPH on GPS), and look where the needle points. Then do the same for 40, 50, 60 MPH etc..
Once you know where the needle points at which GPS speeds, you can use a permanent marker, and just add dots and MPH numbers on the plastic.
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Post by lykos23 on May 28, 2013 20:02:02 GMT -5
Here are some results from my ongoing experiment in a different thread/forum...:
These are my speeds with different terrain and sliding weights comparing gps and my speedometer:
Speedometer speed - GPS Speed
4g:
35mph uphill, 33mph GPS
40mph flat terrain, 36mph GPS
45mph downhill, 39mph GPS
Three 4g and three 9g:
32mph uphill, 28mph GPS
40mph flat terrain, 37mph GPS
50mph downhill, 43mph GPS
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Post by scootnwinn on May 29, 2013 9:02:25 GMT -5
I have never owned a 2 wheeled vehicle with an accurate speedometer, ever. I have had Hondas, Suzukis, Chinese and now Vespa. I have ridden everything under the sun pretty much and they were all wrong. My current speedo is slow so when it says 35 its more like 42 I have GPS data that says I hit 70 but it never read over 60. So figure out how off it is and run it.
Most Japanese cars I have owned were a bit optimistic too...
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Post by barnie on May 29, 2013 19:18:05 GMT -5
I have a JCL MP250a with linhai 257 engine. My speedo was off also so I bought a Astrale Cateye electric bicycle speedometer. the Cateye 8 will read up to 185 mph. mounting takes a little fiddling but end results are the little magnet attached to hub on front wheel with the sensor mounted on fork and you measure outside dia of tire in inches and convert to millimeters and set the speedo head to match. This thing is dead accurate at all speeds checked with my suv. It also has an odometer etc. I rarely look at my in dash factory speedometer. Barnie  |
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mph gps said 68 speedo is right up to 30 mph gps confirmed it but after that it seams like 1 mile for every 5 its off so I just keep up with traffic or other scoots I ride with lol most of them are 100 cc or less lol
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