BloomBikeShop
04-05-05, 04:19 PM
How accurate is the power function of the Ciclosport HAC4? How does it compare to the Polar unit?
Training & Nutrition - Ciclosport HAC4 as power meter
Bikeforums.net is a forum about nothing but bikes. Our community can help you find information about hard-to-find and localized information like bicycle tours, specialties like where in your area to have your recumbent bike serviced, or what are the best bicycle tires and seats for the activities you use your bike for.View Full Version : Ciclosport HAC4 as power meter
pacesetter
04-05-05, 10:59 PM
No it's a big guess! uses weight and speed to calculate power. ride into a 25mph head wind with a slight grade of 2% it's way off.
Bontrager
04-06-05, 07:59 AM
The HAC4 calculates power like the poster above said. I have the HAC4.
I believe the Polar unit actually measures power by measuring strain or something on the chain.
There's other products that will measure power directly/better. It all matters how much you want to know and spend.
I believe the Polar unit actually measures power by measuring strain or something on the chain.
There's other products that will measure power directly/better. It all matters how much you want to know and spend.
BloomBikeShop
04-06-05, 08:37 AM
Yeah, I'm thinking of getting the Polar S720i and then adding the power unit.
(My other bike is a jeep too)
(My other bike is a jeep too)
Guest
04-09-05, 05:45 PM
The HAC4 calculates power like the poster above said. I have the HAC4.
I believe the Polar unit actually measures power by measuring strain or something on the chain.
There's other products that will measure power directly/better. It all matters how much you want to know and spend.
I believe you are correct. I actually read a report that compared the different systems that measure power. At the top of the list was the PowerTaps being the most accurate, with the Polar unit slightly behind the PowerTaps. What they didn't like about the Polar unit was that the power reader is a bit difficult to work with because it seems to slide off the chain or around the chain at times.
Both units are pretty expensive, although the PowerTaps is far more expensive than the Polar.
Koffee
I believe the Polar unit actually measures power by measuring strain or something on the chain.
There's other products that will measure power directly/better. It all matters how much you want to know and spend.
I believe you are correct. I actually read a report that compared the different systems that measure power. At the top of the list was the PowerTaps being the most accurate, with the Polar unit slightly behind the PowerTaps. What they didn't like about the Polar unit was that the power reader is a bit difficult to work with because it seems to slide off the chain or around the chain at times.
Both units are pretty expensive, although the PowerTaps is far more expensive than the Polar.
Koffee
acrafton
04-10-05, 07:07 PM
I had a HAC4 and now have a PowerTap and the difference is huge. Do not use the HAC4 as any kind of power meter - it is simply too far off. Perhaps indoors with no wind or gradient it would be closer but in the real world it is way off. Keep in mind that the HAC4 only records once every 20 seconds so it often 'misses' gradients and does not take into account winds.
For example, I compared PowerTap recordings to HAC3 recordings over the same route/conditions and the readings averaged 30-50% off and sometimes even higher on climbs.
I liked the HAC4 and think it is a fine cycling computer but it is worthless as far as watts go. . .
Adam
For example, I compared PowerTap recordings to HAC3 recordings over the same route/conditions and the readings averaged 30-50% off and sometimes even higher on climbs.
I liked the HAC4 and think it is a fine cycling computer but it is worthless as far as watts go. . .
Adam