Originally Posted by
gpburdell
Product page has the dreaded "up to" qualifier on that 153yd/140m specification - so 400ft instead of 459ft (153yd) isn't that far out of line -- and it's possible Ghostride62 was approximating the distance as well.
Is that enough? I'd say it depends on one's situation. With a closing speed of 60mph - such as riding 10mph with traffic going past you at 70mph, you'd get 4.5 to 5 seconds warning. With a 30mph closing speed the time is 9-10 seconds.
All I know is on the roads I ride, my Varia tells me about cars before they're easily seen in my mirror, and I can easily hear the alert tone on my 830. Maybe the system isn't perfect, but I'm better aware of cars than when I was just using a mirror.
From the time I put that in the post I was wondering if any would do the math and convert yards to feet. So good for you catching on that. I can only sarcastically say or suppose why is it okay for our stated distance be off by almost 15% when there are people in other threads griping about their distance being reported for a ride as off by 2% is a big issue. So probably a private joke that wasn't going to work well anyhow.