has anyone compared the mph on odo vs gps?

I wondered what the difference in speed between the two, I will do that tomorrow.

There's about 10% difference in my case. An indicated 70MPH on the GPS and the scooter reads about 64 MPH

"There's about 10% difference in my case. An indicated 70MPH on the GPS and the scooter reads about 64 MPH"

I think this statement is reversed. Usually the actual speed is less than the speed indicated on the bike's speedometor.

Yes you're absolutely right, what a plonker I am.

My GPS shows 4 mph over speedometer of scoot.
I am going to do a test today to test the odometer reading.
I will be back.
Gary

My speedo reads 3-4 mph faster than the GPS (50 indicated, 46 (gps actual). Garmin SP2610

ok today I noticed 3-4 mph difference when going slow speeds around 20 to 50mph but any higher the difference is 5 to 6.

I just finished a fairly long circular trip ( approximately >142 mi) to test something else. You can check out the comparing odometer to gps thread on this forum for specifics. I tried to verify exact differences, but could only get approximates. I found that for speeds up to 20 mph there was no visible difference. At 25 - 30 the difference was about 1 mph. At 35-40 the difference was about 2 mph. At 45 - 50 the difference was 3 mph. At 55 - 60 the difference was 4 mph. I did not look at faster speeds, but it appears to me that we can interpolate a curve about 1 mph increase for every 10 mph of the odometer.
This is just for my scoot. I am sure there will be different values for each scoot.
My Ford truck is consistently 5 MPH fast almost at any speed on the GPS.

Gary

Opalsboy wrote:

I found that for speeds up to 20 mph there was no visible difference. At 25 - 30 the difference was about 1 mph. At 35-40 the difference was about 2 mph. At 45 - 50 the difference was 3 mph. At 55 - 60 the difference was 4 mph. I did not look at faster speeds, but it appears to me that we can interpolate a curve about 1 mph increase for every 10 mph of the odometer.
Gary

Gary,
My experience is essentially the same. I did test mine up to about 85 mph and your theory holds - about 1 mph increase for every 10 mph on the speedo. At 65 speedo I was 60 on the GPS, at 75 speedo the GPS says 69. AT 85 speedo, the GPS indicates 78.

One nice side benefit of the darkside tire is that the speedo is accurate up to about 65 mph. Over 65 the speedo is about 1 mph faster than the GPS.

Not on GPS, but I've checked against mile markers and those roadside radar-speed things. The speedometer is about 5 mph fast at an indicated 70, and the odometer is equally screwed up.

My Toyota Tundra has the only accurate speedometer I've ever seen. With new tires it is absolutely dead nuts on. Less than 1/10 of a mile off during a 500 mile trip. I don't think even the GPS is that accurate.

Most cycles speedometers read a little faster than you are actually going. Some are worse than others. You will hardly ever find one that is right on...My Silverwing is a 2005 and it graduates with speed but at 69 indicated on my speedometer, the GPS is showing 65 mph. Don't get alarmed because they are all that way.

http://en.wikipedia.org/wiki/Speedometer

See 'error'

There are devices to help you fix that, but they usually cost about $100 plus installation. Not worth it, especially if you have a GPS.

I get the same as Gary (Opalsboy) on my gps. So if you want to go 65 mph (actual) then you can go 70 mph on your speedo. When I go 100 indicated I'm doing 93 on my gps.

Don't forget that tyre pressures will have an impact. If you're running low or high compared to the recommended for your set-up, that'll affect your reading.

In the UK, it's rumoured that the Police allow a 10% margin before 'talking' to you about your speed. I'd trust GPS over mechanical speedo any time, but it's useful to know how much the speedo is out by, if only for the sake of your licence!

Tested my bike's speedometer. When the speedometer is reading 110 kph the GPS was reading 102 kph. 2 friends were with me at the time. One on a Suzuki Strom. His read 103 on GPS versus 110 on Speedometer. The other bike, a Kawasaki Concours, read GPS of 105 against 110 on the speedometer.

I haven't measured on my Swing yet, but the variable in the car is about 8 mph. The GPS always shows a lower speed.