John Eucist Posted June 10, 2016 Share Posted June 10, 2016 This video is a bit worrisome to me since I'm considering buying an ACM. Check out the part before 7:44 where the rider "runs off" the euc while (I think) holding two phones. The Gotway app showed 43 km/h right before "the crash" but judging from the movement of the scenery prior to the crash it looked closer to HALF the speed. Have any existing ACM owners measure the difference between the gotway app speed with a gps speedometer app? What REAL speed have you attained riding it? Link to comment Share on other sites More sharing options...
Reivax Posted June 10, 2016 Share Posted June 10, 2016 To me, such tests should never use GPS measured speeds. GPS make an estimate, and I've had speeds up to 90km/h with my MCM2 (!) reported by GPS based applications. In my experience, Gotway App is 2 to 4 km/h more than real speed, measured with a bike odometer. As for judging from the scenery movement, I find it really hard to tell, the impression will be so different depending on the height the camera is held, but also the lens angle, ... it's at night too... Not even mentioning that the video is to the side Look at 0:18 on the video below, I was riding my MCM2, at less than 15km/h and it looks like a hell of a speed, because I hold the camera need the ground: Link to comment Share on other sites More sharing options...
John Eucist Posted June 10, 2016 Author Share Posted June 10, 2016 9 minutes ago, Reivax said: To me, such tests should never use GPS measured speeds. GPS make an estimate, and I've had speeds up to 90km/h with my MCM2 (!) reported by GPS based applications. Yeah what I really wanted to emphasize was that the gw app speed appears to be almost double the real speed in the video. I have replaced the word "gps" in the title with "real" to change the emphasis. That said, if you keep a constant speed over a significant period of time, the gps "average speed" should be pretty accurate. Link to comment Share on other sites More sharing options...
Reivax Posted June 10, 2016 Share Posted June 10, 2016 6 minutes ago, John Eucist said: Yeah what I really wanted to emphasize was that the gw app speed appears to be almost double the real speed in the video. I have replaced the word "gps" in the title with "real" to change the emphasis. That said, if you keep a constant speed over a significant period of time, the gps "average speed" should be pretty accurate. Still I think it needs to be measured, because the speed feeling might be biased. I know a large pavement near my home where I always have a feeling of riding fast, but I get no beeps. It's smooth and flat, I don't know what triggers the feeling of going unusually fast, but I've experienced it several times, always at the same spot. Link to comment Share on other sites More sharing options...
Mono Posted June 10, 2016 Share Posted June 10, 2016 I wouldn't trust judgements from the movement of the scenery unless I know the environment, but I would judge the chances to run off 43km/h to be pretty much zero. Link to comment Share on other sites More sharing options...
OliverH Posted June 12, 2016 Share Posted June 12, 2016 I know a guy managed to run off a KS18 (1st gen 500 W motor) which is above 30 km/h. He struggled, but managed it. Al above is very hard and chances are very low if you don't plan to run off. A power cut comes immediately. Link to comment Share on other sites More sharing options...
Leech Posted June 13, 2016 Share Posted June 13, 2016 On 6/12/2016 at 11:49 AM, OliverH said: I know a guy managed to run off a KS18 (1st gen 500 W motor) which is above 30 km/h. He struggled, but managed it. Al above is very hard and chances are very low if you don't plan to run off. A power cut comes immediately. Topic is about ACM, its power cut lies much beyond 35 km\h on smooth surface as i tested. Link to comment Share on other sites More sharing options...
OliverH Posted June 13, 2016 Share Posted June 13, 2016 4 hours ago, Leech said: Topic is about ACM, its power cut lies much beyond 35 km\h on smooth surface as i tested. My comment was about the run off at around 30 km/h. I really can't believe that it can be done at more than 35 km/h. Link to comment Share on other sites More sharing options...
Cloud Posted June 14, 2016 Share Posted June 14, 2016 On 13 июня 2016 г. at 4:22 PM, OliverH said: My comment was about the run off at around 30 km/h. I really can't believe that it can be done at more than 35 km/h. A run off cannot even be done at 35. The world sprint record is 37 kph. Even if the sprint champion tries to run off at 35, he wont be able to do that as this comes in suddenly with no prior acceleration. For regular people a run off at higher than 25 kph is almost impossible, Link to comment Share on other sites More sharing options...
Nevin@Tec-toyz.com Posted June 17, 2016 Share Posted June 17, 2016 I wouldn't trust the GPS speed as well. I find many discrepancies between my Strava APP and runtastic APP. The GotWay APP based on what I've heard runs off the RPMS from the wheel. It does seem to be off at times by 2-3kmh. Further testing needs to be done. Link to comment Share on other sites More sharing options...
TremF Posted June 18, 2016 Share Posted June 18, 2016 10 hours ago, NevNutz said: I wouldn't trust the GPS speed as well. I find many discrepancies between my Strava APP and runtastic APP. The GotWay APP based on what I've heard runs off the RPMS from the wheel. It does seem to be off at times by 2-3kmh. Further testing needs to be done. If the Gotway speed is based on the RPM's then it will require the tire pressure to be just right to be accurate. Too low a pressure will report a higher speed than you are travelling and too high will report a lower speed. If the app is reporting 2 - 3 kmh faster then peolpe need more air BUT according to my ACm's tire it should be set to between 40PSI minimum and 50PSI maximum. I set it in between at 45PSI but I am finding the ride too hard so need to drop back to 40PSI I think. This means that you may not be able to get the right pressure for the right speed due to comfort. ? Link to comment Share on other sites More sharing options...
John Eucist Posted June 18, 2016 Author Share Posted June 18, 2016 2 minutes ago, TremF said: If the Gotway speed is based on the RPM's then it will require the tire pressure to be just right to be accurate. Tire pressure will make a difference but not THAT much of a difference. Gotway has been known to inflate the figure on their apps. Whether intentional for deception or due to incompetence I dunno. Link to comment Share on other sites More sharing options...
dmethvin Posted June 18, 2016 Share Posted June 18, 2016 If you are in a place where it can't get good GPS lock the GPS-measured distances may be off because it records the wrong location and thinks you're traveling longer distances than you really are. That will lead to it thinking you are traveling at a higher speed . If you are doing a lot of zig-zag motions it is also possible you are traveling a longer distance than the GPS readings show, leading to a lower speed reading than reality. When I use MapMyRide I see instantaneous "max speed" GPS numbers of up to 50kph on almost every trip that I know are crazy, since my wheel shuts off around 30kph and I generally don't go faster than 25kph. When the reading is coming off the wheel the instantaneous numbers for both distance and speed should be pretty accurate. Let's say you have a 16 inch wheel and the effects of tire inflation could be as much as 1/2 of an inch difference in the 8-inch radius. That would make the worst-case error (1/2 in 8) or (1 in 16) or 6.25 percent. If you were traveling 20kph that would only be an error of plus or minus 1.25 kph. Obviously there might be other reasons like the app having software bugs that prevent it from having an accurate reading, but as long as they get a signal every rotation they should be able to do the calculation accurately. Link to comment Share on other sites More sharing options...
Cloud Posted June 18, 2016 Share Posted June 18, 2016 Ive downloaded "speed box" on my iphone from thr app store, and i believe it was free. I dont have a gotway but i compared it against my kingsong and every time the speed in the app is spot on matching what kingsong app shows. Perhaps this app can be used to check gotway speed? Now, of course, this is under the assumption that kingsong speed is accurately shown in the kingsong app. Theoretically both sources could be equally wrong. But still its something to go by and appears precise and several experiments show consistent results Link to comment Share on other sites More sharing options...
John Eucist Posted June 18, 2016 Author Share Posted June 18, 2016 3 minutes ago, Cloud said: Ive downloaded "speed box" on my iphone from thr app store, and i believe it was free. I dont have a gotway but i compared it against my kingsong and every time the speed in the app is spot on matching what kingsong app shows. Perhaps this app can be used to check gotway speed? Now, of course, this is under the assumption that kingsong speed is accurately shown in the kingsong app. Theoretically both sources could be equally wrong. King Song app has always matched my GPS speeds with multiple GPS apps on both iPhone and Android (Note 4). Link to comment Share on other sites More sharing options...
Cloud Posted June 18, 2016 Share Posted June 18, 2016 2 minutes ago, John Eucist said: King Song app has always matched my GPS speeds with multiple GPS apps on both iPhone and Android (Note 4). Great, lets use it to check gotway speed then Link to comment Share on other sites More sharing options...
Dominique B. Posted July 12, 2016 Share Posted July 12, 2016 Guys you are turning around the pot many GPS apps are accurate to mesure the speed you just have to chose a straight road with no threes around on a sunny day and you get your max speed mesured in 1 minute. I measured my mcm4 max speed several times and it is 22 kph nothing more and this with tilt back on and just before the first beep. Removing the beeps would mean face plant few kph later not worth trying it hurts a lot... We need the constructors to adapt their technology to our needs that's it... Gotway is coming with a new msuper 3 which speed should be above our expectations! Let's wait and see ! Link to comment Share on other sites More sharing options...
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