Originally Posted by
Seattle Forrest
I had the old, magnet-based GSC-10 and still have my 800. I was never able to get the speed sensor to work reliably, it would often display zero. I ultimately gave up and have been using GPS for speed ever since, with no ill effect.
Learn my on the need for a speed sensor ?.
I kept my Cateye sensors on my bike when I added a Garmin 810 and do notice that there's a slight lag on the 810, maybe 3-5 seconds at best ?, of current speed. Distance seems to be off about a mile in 100 and the auto-stop/start is different as well, so I guess ride distance/time/avg. is different, but somewhat a "so what".
So why do these exist ?.