So my Filzer dB4lw-c cyclocomputer works fine above 55F, but the speed registers 1/2 what I'm actually traveling below that, and around 32F, seems to not really work much at all.

I have replaced the battery in the wireless speed sensor, and all other functions (cadence included) work fine. Is there water in the reed switch in the speed sensor or something? I'm stumped.

I'd bet that the battery in the transmitter just isn't happy about the cold. The receiver shouldn't be drawing much power anyway, so the transmitter would probably be the first suspect. Seems awfully sensitive though, 55 degrees is far too warm to start getting temperature related issues.

I use a Planet Bike Protege 9.0, and I haven't had it not read properly yet. Last week I was riding at below -20*F (the onboard thermometer just read "--") and the display was barely readable even in bright light, but it was working and registered the same distance for my commute that it always does.

Personally I would never use a wireless, but I guess that's personal choice. I don't trust wireless all that much, plus they go through batteries at much more than twice the rate that a non-wireless does (mine uses a single CR3250, and I only have to replace it about every 18 to 24 months).

I don't even run wireless for my home network, except for one laptop which actually rarely gets used at home. I pull wires through the walls anywhere that a computer will be installed. My motto is, wireless might be nice, but wires "Just Work."

Get my money back and buy a different brand, is what I'd do.

lucky that's your only issue. my cassete keeps skipping and being utterly annoying to ride with. Once it warms up a little, it's fine. Must not like 10F weather any more than I do...

the battery just gets cold, happens with my camera batteries all the time. Can you bring your bike inside for a while prior to your ride?

@ Roody- love the signature.

I run an 'el cheapo' Topeak 150 Wireless, and have never had a problem until this morning, when it was close to 0*F, and the problem was intermittent. I knew that I was due for a battery, so I will change it, but other than today, I have never had a problem with my wireless setup.

Thanks.

My wireless computer would malfunction below 5C (40F) and only register about 1/4th my distance on cold days. I put new batteries in the transmitter and computer but it had no effect other than resetting my odom. In the end, I replaced it with a cheap wired computer and haven't had any problems since.

I've almost never had a cold weather problem with the cheap wired Cateyes that I use. One time one died in a very severe rain squall, but they replaced it immediately under warranty--even though I didn't have the receipt with me.

I've never had to replace a computer battery, because I'm pretty bad about losing them and breaking them before the battery runs out. My LBS will sell me the display head only (without the sensor. magnet and mount) for a few bucks less.

Even so, I have the sensors and mounts on three or four different bikes, so I can put the one display head on any bike. I like it that way.

Wow, there's a good reason not to go wireless, if I needed another (my first one is, I never figured out what the point was of spending more money to get something more complicated to do the same job). That computer wouldn't work right here probably 5 months out of the year, at least on many mornings.

That is an EXCELLENT idea. I will do that to ensure that it is in fact the root cause!

Thanks nahh!