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Just Got a 4iiii Power Meter. Do I need my Cadence Sensor?

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Just Got a 4iiii Power Meter. Do I need my Cadence Sensor?

Old 01-13-20, 05:24 PM
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illjustride
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Just Got a 4iiii Power Meter. Do I need my Cadence Sensor?

Hi everyone. New here. Psyched to join and spread knowledge in cycling and learn along the way. I just bought a 4iiii Ultegra power meter for my bike. I'm wondering if I need the cadence sensor attached from my old arm on the new arm as I heard that they also have a cadence sensor build in. Just wanted to clarify and ask if anyone can help with this.
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Old 01-13-20, 06:00 PM
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Originally Posted by illjustride View Post
Hi everyone. New here. Psyched to join and spread knowledge in cycling and learn along the way. I just bought a 4iiii Ultegra power meter for my bike. I'm wondering if I need the cadence sensor attached from my old arm on the new arm as I heard that they also have a cadence sensor build in. Just wanted to clarify and ask if anyone can help with this.
No. Power meter will provide cadence. You can search for a cadence sensor on a head-unit and the same ANT ID will show up for both power and cadence.
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Old 01-13-20, 06:34 PM
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Seattle Forrest
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To determine power at the crank arm, it needs to know how hard you're pressing and how fast you're turning the pedals over. And PMs all promise somewhere in the ballpark of 2% maximum error, which they can't achieve by relying on an external cadence sensor, so they have their own.

Not all PMs have a cadence sensor because if you measure at the hub, you don't need cadence. But yours does.
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Old 01-14-20, 10:42 AM
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Welcome to the forums! I have a 4iiii PM as well. Great device. Can't speak highly enough about the unit (even if the L/R issue has yet to be sorted via a software update). I had the same question as you when I installed my PM. The good news? No need for a cadence sensor. The PM will handle that for you. As @saverin mentioned, you just need to bring the field up on your bike computer. Cheers.
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