seems to be very accurate when at rest, and most of the time, when riding easy. mostly. but it can rise up to the 140s, to 160, and seems to get stuck on certain numbers.
then when riding extremely hard, it will show low numbers, and start to slowly drop from there. then is seems like some passing cars will affect the reading as well. maybe newer ones, with lots of electronics and stuff? IDK. but this thing is pretty much worthless.
i have checked everything on the strap. battery life. battery contacts. chest contacts are clean
i have a Polar H10 transmitter strap on the way. maybe i'll have better results from that one.