Mine is showing a lot of zero. I went for a 20 mile ride last night, and the computer recorded 9 of them. I'm not sure how much of today's ride I "got credit" for, but I looked down a few times and saw zeros. The speed and cadence seem to come and go at the same time. The magnets seem to be aligned properly.

Battery? Time to smash the computer and look for a new one? I got this one about two months ago, with the bike.

maybe a lemon...i have tow of them and they work great.

Since the magnets are aligned and the speed/cadence go out at the same time, I'd go with your first thought...change the batteries. I have Stradas on two of my bikes, and haven't had any problems with either of them.

I have a double wireless and it happened to me as well but only a couple of times in say 2000 km.
Make sure the sensor is as close to the magnets as possible.

Did you use a headlight on your ride? I have a Niterider Newt and if I have it on flash mode or low beam the light interferes with the wireless transmission. For some reason the high beam is not problem for the computer.

Is it getting cold where you live? Is the wheel sensor at the maximum distance from the handlebar? My Cateye quit working in cold weather. The batteries weren't performing as well in cold so I moved the sensor closer.

I'll check the sensor distance from the magnet, but the transmitter is on the chain stay. Thanks for the advice, everyone!

Mine doesn't do well in the cold either. Zero speed and distance, as if I was standing still. Back in the garage, it works fine.

Batteries, or no?

It's easy enough to check the batteries - spin the tire and see if the little icon indicating it's receiving a signal is pulsing. If not, replace the sensor battery.

I've found mine lasts around 6 months. May as well change both at the same time, since batteries come in packs of two. :-)