On our local commuter board, there was this discussion about how the "loops" that trigger lights can sometimes make one's wireless cyclocomputer go haywire.
Then, someone with a GPS reported:
On my Saturday ride it said I was doing 1083 mph in the I-90 bike tunnel How is that for an interval? On my ride yesterday it logged 12 miles while was having pancakes and coffee in the U district. Riding to eat is one thing, but eating to get miles is yet another.
I don't have a GPS, myself, but I thought that this was pretty funny.Do other people have tales from the road like this one?
On our local commuter board, there was this discussion about how the "loops" that trigger lights can sometimes make one's wireless cyclocomputer go haywire.
....
Quoted message said:
I don't have a GPS, myself, but I thought that this was pretty funny.Do other people have tales from the road like this one?
It happens fairly rarely, but occasional glitches in GPS position and speed calculations do occur. GPS depends on the signals coming to the receiver on a direct line-of-sight so the time of travel is an accurate measure of the distance to the satellite. But sometimes you can have a situation where a satellite is hidden by a hill or building but the receiver still gets a reflected signal from it (known as multipath). That can cause a sudden jump in the apparent position of the receiver and also an erronious speed indication which is determined both by position data and direct Doppler speed measurement.
My highest recorded speed while cycling was a case like this where signals probably reflected from a hospital complex on a hillside behind me. My GPS tracklog showed me making a sudden jump to a spot a mile or so away and the Max Speed indicated 4032 mph.
It's also sometimes possible for the GPS under poor reception conditions to lock onto a false position solution which is very different from the real situation. One example was when I was cycling south on a bike path at about 15 mph in an area east of San Francisco, but my GPS thought I was out over the north Pacific at an altitude of 1500' and approaching Seattle at 724 mph. It continued to show that situation for quite a few minutes until it got some additional satellite signals and reset itself to the correct position and speed solution.
On our local commuter board, there was this discussion about how the "loops" that trigger lights can sometimes make one's wireless cyclocomputer go haywire.
Then, someone with a GPS reported:
On my Saturday ride it said I was doing 1083 mph in the I-90 bike tunnel. How is that for an interval? On my ride yesterday it logged 12 miles while was having pancakes and coffee in the U district. Riding to eat is one thing, but eating to get miles is yet another.
I don't have a GPS, myself, but I thought that this was pretty funny. Do other people have tales from the road like this one?
I remember one time, I was waiting at a light and, it said I was doing 150mph. I thought it was a rarity, till I read this.
I wonder what it would sound like, if a cyclist actually broke the sound barrier(761mph). At 1083mph, you would be zooming at Mach 1.4
My GPS tends to lose its position whenever riding near power lines. Generally this only happens when riding parallel to them at a close distance but the high power transmission lines can also cause a brief interruption when crossing underneath.
