I've been using my HAC4 for 4-6wks now and it seemed that my power output was low (avg ~100watts) even though my performance was med/high (21-23mph avg on flat @ 240lbs rider+bike+equipment). I went to the analytic cycling page and based on my numbers I should be registering ~300 watts, far from the ~100 the HAC4 is telling me about.
turns out there looks to be two groups. One group down around 100ish and the second up around 2-300. Very weird...
I blame the HAC4 algorithm's dependency on altitude gain, it seems if your not gaining altitude you can't exceed 100 watts easily even at 21mph @ 240lbs on the flat/slight incline (<2%).
I've been using my HAC4 for 4-6wks now and it seemed that my power output was low (avg ~100watts) even though my performance was med/high (21-23mph avg on flat @ 240lbs rider+bike+equipment). I went to the analytic cycling page and based on my numbers I should be registering ~300 watts, far from the ~100 the HAC4 is telling me about.
turns out there looks to be two groups. One group down around 100ish and the second up around 2-300. Very weird...
I blame the HAC4 algorithm's dependency on altitude gain, it seems if your not gaining altitude you can't exceed 100 watts easily even at 21mph @ 240lbs on the flat/slight incline (<2%).
Anybody else???
it won't be anywhere near accurate for level ground cycling or even going uphill if you're going quite fast (probably need to be going uphill at less than 20 km/hr for it to approach reasonable accuracy)
it won't be anywhere near accurate for level ground cycling or even going uphill if you're going quite fast (probably need to be going uphill at less than 20 km/hr for it to approach reasonable accuracy)
ric
Yep mine is not even close to accurate and I know for a fact that I have all my info entered in correctly. If you want to use power to train I'd suggest getting a real power meter, however the HAC4 is an awesome cyclocomputer aside from the power estimation.
Yep mine is not even close to accurate and I know for a fact that I have all my info entered in correctly. If you want to use power to train I'd suggest getting a real power meter, however the HAC4 is an awesome cyclocomputer aside from the power estimation.
I've compared mine to a SRM and it gave me the same values as what he had. We rode next to each other with the same gears and speed.
it must've been pure luck then as it's highly unlikely the HAC4 can be accurate (especially on flat roads)
ric
Yes it was on a climb when we compared it, and never again. But if you train using your hac read out and you see improvement on it say in 2 weeks time then I guess its ok using it as a guide line. Obviously if you want accurate reading then you will have to spend that extra money.
Yes it was on a climb when we compared it, and never again. But if you train using your hac read out and you see improvement on it say in 2 weeks time then I guess its ok using it as a guide line. Obviously if you want accurate reading then you will have to spend that extra money.
I just thought it was good value for money.
it's likely to be reasonably accurate on climbs, however, it's possible to calculate power to about the same accuracy with a calculator for hills when you get home.
I blame the HAC4 algorithm's dependency on altitude gain, it seems if your not gaining altitude you can't exceed 100 watts easily even at 21mph @ 240lbs on the flat/slight incline (<2%).
Don't blame the algorith, just understand how it works.
I live in a fairly (read very) hilly area in SW England. I find the HAC4 power reading to be great and ride with it on most of the time (cadence on the flat). The reading is very consistent on grades of 3-4% upwards but there is a time lag involved. It certainly lets you know if you are slacking! If it rains forget it, I have achieved some amazing power outputs when rain gets into the little sensor holes on the side 😄
