HAC4+ records speed when not moving?
 

I apologize in advance if there have been previous posts on this, but I did look and couldn't find one; nor could I find anythnig on the HAC4 website.

I'll start out by saying that I love my HAC4. Yes, it's quirky to set up and it could be designed better, but I love reviewing the training logs and analysis on my computer after each ride: "Look honey, this is where I sprinted to beat the light... this must be when I releived myself...etc.

About a month ago the unit started recording speed between 4 - 8 mph when I was stopped. At first I thought it was interesting and I was appreciating the extra mile or so after each ride, but now it's really annoying me. It's also recorging elevation changes and climbing stats while I'm locked into my trainer. Does anyone have any advice on correcting this? Will a reset work or is there a menu option for recalibrating

Advanced appreciation for any help.
Best,
MC

I have a HAC4 and it's my understanding that while the head unit shows stats in real time, it only records data every twenty seconds. For instance, I may stop for a red light, but it changes fifteen seconds after I stop. The log shows no stop, but shows a huge slowdown there. I create a 'marker' every time I have to stop the bike and sometimes am amused to see that what I called a stop shows me going at a decent clip. I don't know if that's what you're seeing or not, though.

As far as elevation changes and climbing stats, the altitude is based on barometric pressure, IIRC. Climbing stats (% ascent, etc.) are calculated off the recorded altitude and distance travelled. If the air pressure is changing where your trainer is located, it would look to the HAC4 like you were climbing or descending. As air is a vapor, temperature changes will affect pressure.

I use the data as a motivational tool/rough guide. If you're using the Hactronic software, you can edit the raw data once you download it from the head unit. Maybe you could contact Ciclosport support and ask them if it needs repair/adjustment? Good luck and let us (or at least me) know what you find out. I'm always curious what kind of support I can expect should I ever need it.

Maybe you're recording the rotation of the earth! <just kidding>

Could be that it is picking up RF noise from some source. For example it will register speed and heart rate while in my van while the engine is running, ignition noise. Also it will record 50 mph when I'm riding on the BART train, from the electric motor drives running the train.

To prevent this, I detach the HAC4 from the base. and set the display to temp and time.