Bicycles Stack Exchange
Bicycles Stack Exchange

Questions tagged [power]

Power meters and all related data analysis. This includes how to train with power.

Power meters measure direct force applied to one of the pedals, crankarm, crankset, rear hub, or other methods.

They use cadence in conjunction with the force to measure the power or wattage.

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What method or algorithm is used for computing power curve on Strava?

Many cycling analytics apps like Strava, TrainingPeaks or GoldenCheetah are offering the critical power curve chart, computed from the power meter data. I'm familiar with the curve meaning and usage, but I'm curious how the curve is computed from…
JirkaV
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Is it possible to burn only ~850 cal. on 1.5h / 20 km fast bike ride?

I have just recorded two following activities (I am 42 years old and seriously fat / 108 kg): Hike: 9.04 km / 1h20m / 90 m elev. / 1,220 kcal Bike: 20.26 km / 1h25m / 146 m elev. / 837 kcal Is this kcal burnout on second activity accurate /…
trejder
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How can consumers test if their power meters are accurate, and how should we address discrepancies?

Over time, serious cyclists may get multiple power meters. As a minimum example, you might get a power meter for your bike, and later you get a smart trainer. DC Rainmaker and GP Lama do extensive cross-testing of power meters and smart trainers to…
Weiwen Ng
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Changing from Ultegra 6800 crank to r8000 dual power meter

I currently have a shimano ultegra 6800 crank set on my 2014 trek speed concept 7.0. I want to install a dual side power meter and can only find the r8000 dual side power meter setup. Will the r8000 work on the bike I’m riding?
Bryce
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What to consider buying a single left side power meter from stages?

My current crank arm is 175 cm. I have a Giant Contend 3 with the following parts: Rear Derailleur- Shimano Claris Front Derailleur - Shimano Claris Crank - FSA Tempo, 34/50 Bottom Bracket - cartridge What characteristics or model should I buy for…
tread
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Understanding how to calculate critical power curves

Hello fellow cyclists, There are services out there that can calculate power curves based on your bike ride (when training with a power meter). This curve shows the time to exhaustion (t) based on the power P. So let's assume that my maximum power…
Sascha S
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Solar charger for iPhone whilst on a bike tour - is it worth it?

Are there any feasible solar chargers for iPhone / or with a usb slot that will work or is a backup battery available. Best value (and something that works) is my priority. I found this brilliant link on crazy guy on a bike-…
Andrew Welch
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What is the difference between a speedometer and a power meter in terms of performance measurement?

If I cycle the same route every day, what would be the benefit of having a power meter over a speedometer? Can't I just measure my speed and compare it against my last run and see if I've done better?
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Reverse FTP measurement

Often it is argued that an 8 or a 20 minute effort can be sufficient to estimate Functional Threshhold Power (FTP), an indicator of how many watts a rider can put out over the course of an hour (or 40 minutes, depending on who you ask). For a 20…
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Does a crank arm Power Meter measure power in both directions?

The leg on the upstroke weighs down on the pedal and creates additional work for the leg on the downstroke. A crank/hub power meter ignores that and gives you the effective power combined by both legs. Lets assume a rider generates 120W on the…
AzulShiva
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How many watts is a good push worth?

The other day as I commuted home a stranger gave me a helpful push as I approached the top of a steep hill. It was wonderful, and I immediately wondered if this is what an e-bike boost would be like. Is there some way to calculate how many…
Paul R Pival
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Resurrecting an old style SRM Amateur power meter?

I decided to put my old SRM amateur chainset on my indoor trainer bike, then charged the SRM V unit, but its not working after the charge. I've not used it in 3 years so not surprised, and Im guessing the strain gauge battery is dead too. My…
farrellmr
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Zero Offsetting P1 pedals using just Rouvy android mobile app

I don't have a bike computer, rather I use my old cellphone for that matter. Does anybody know how to do a zero offset of P1S pedals using Rouvy app? Apparently, there should be an option when you pair your sensor, but on my app I don't have one.…
Amir
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Can single-sided Power meters cause unnatural Bilateral asymmetric pedaling?

In case it is not clear for everyone, let me briefly explain the graph. The pink line represents the Power output along the y axis while the grey dots represent Left/Right balance in Power. The x axis represents time. I was aiming for 360 watts in…
AzulShiva
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Which are better for reproducible power output: Mag- or Fluid-trainers?

I'm looking to buy a trainer but my primary concern is being able to consistently improve my power output. To do this I need a way to measure my output consistently - I don't care what the actual power output is, only that I'm consistently…
user1524361
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