Charge 4 won't track my heart rate accurately when cycling

[Martin_cycle]

I know this has been covered many times before, and I've read through and tried all the comments, but I still can't get my Charge 4 to accurately measure my heart rate when cycling. I use it for spin classes regularly, which it seems to monitor accurately, but on my cycle ride to work it refuses to measure anything close to my actual heart rate. I can push myself to my maximum (which would see my heart rate around 165+ on the spin bike) but it won't go above 92 on my commute. It seemed to work accurately on outdoor bike rides in the summer months but now the weather is colder it doesn't work. Often, when I arrive at work or home and get indoors, it will suddenly jump up to 120 which seems more accurate as I'm recovering by them.

Is there anything else to try or is it time to give up on the FitBit? Has anyone found a solution that fully solves this? I like all the rest of the functionality and the app but if it's not accurate there doesn't seem much point in wearing it.

Moderator Edit: Clarified subject

[JuanFitbit]

@Martin_cycle A warm welcome to the Community! Thank you for your message and information. 

Now in winter when you are riding is the Charge 4 exposed  or is it covered?

Remember that there operative temperature for the Charge 4 is from 14° to 104° F (-10° to 40° C) .

If it's covered, is it too tight when you are riding? This might cause that the heart rate not to be recognized correctly. 

Hope this helps you further. 

[Martin_cycle]

Thanks for the welcome! 

Ive tried it covered, uncovered, tighter and looser. None of it seems to make any difference. I have however found a bit of a solution. 
As a right hander, I generally wear the Charge 4 on my left wrist. I’ve discovered that if I switch it to my right wrist when cycling it seems much more accurate, suddenly it’s showing heart rates of 160+ when I’m really pushing it. 
So it’s a bit of a solution, not ideal, but hopefully it will get me through the winter months. 

[CRinCT]

I'm new to the community, but scanning the forum, there are many posts concerning inaccurate HR readings when used outdoors. It seems that Fitbit should clarify their specs. I ran today into a slight breeze with the temperature around 7° C. After 15 minutes I got erroneous readings, but it cleared after running with the wind. I'm familiar with specifying electronics and there are games to be played. Does Fitbit drop the temperature in a chamber and see what temperature causes it to fail or does it actually operate the device at -10° for an extended period of time to see if the devices is accurate for the whole period?  

[Martin_cycle]

So it's now 5 months later and the weather is much nicer - I still have the exact same issues though. This morning I tried it higher, lower, loser, tighter and left wrist/right wrist. None of those positions picked up anything close to an accurate reading. When I did stop and change position it would jump to 140+ but when I was cycling is would show 105. What's frustrating is that the little heart icon keeps pulsing as though it's picking up a reading, but it shows something really low.

So, is there anything else I can try, or would I be better with a different Fitbit? I do like the app and the user interface, I'm just disappointed with the constant inaccuracy when cycling.