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36 votes

What applications exist for bicycle power, besides propulsion?

Bicycles are simply a method of generating rotational mechanical movement from biological sources. That rotational energy can be used for anything where a motor would be used. The items below have all ...
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17 votes

Is it possible to burn only ~850 cal. on 1.5h / 20 km fast bike ride?

Since the other answers and comments were discussing only your bike trip, I will tackle on your hike values and show why they are probably incorrect. First of all your activity wasn't a hike, but a ...
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  • 171
15 votes

What applications exist for bicycle power, besides propulsion?

Foot operated sewing machines were very common before electric machines appeared. Unlike hand operated machines they allow using both hands for cloth adjustment, and other energy sources like rotating ...
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  • 3,766
13 votes
Accepted

How to convert calories to watts on Strava rides?

Turning my comment into an answer: Watts in a bicycling context are usually measured (or estimated) as mechanical power at the wheel (or crank). Calories burned are the (estimated) total input energy. ...
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  • 19.6k
12 votes

Is there publicly available data on riders' critical and maximum power?

Getting data on professional riders is harder now than it used to be: in the past, teams and riders would sometimes post their data on Strava or in WKO format. I suspect, but do not know, that this ...
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  • 13.6k
12 votes

Is it possible to burn only ~850 cal. on 1.5h / 20 km fast bike ride?

The bicycling calories sound about right (maybe a bit too high, but assuming a relatively bad bicycle and higher moving speed between breaks it could work). I think it’s your walking calories which ...
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  • 19.6k
9 votes

What are (a) the source of and (b) the justification (e.g. experimental) for the concept of "normalized power" used in physical endurance training?

My understanding is that high-intensity efforts are disproportionately taxing, and NP is a way of reflecting that. That is, if you went for one ride where you maintained a steady 75% FTP output, and ...
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  • 24.1k
8 votes
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Giant power meter left/right balance

Typically, we don't need to pay too much attention to left/right balance because it's not clear that 50/50 is the optimal balance to aim for. Many of us have a slight imbalance. The advice isn't ...
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  • 19.3k
8 votes

How to convert calories to watts on Strava rides?

Minor detail for the general audience: the ride in question lacks actual power meter measurements. It's pretty likely that the cyclist in question wanted to keep her power meter data off Strava, as ...
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  • 19.3k
8 votes

What applications exist for bicycle power, besides propulsion?

Bike-powered smoothie makers are a thing you can rent or buy. They're most often seen at events promoting science/engineering careers to kids, or sustainable travel. Bike-powered electrical ...
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  • 46.2k
7 votes

What are (a) the source of and (b) the justification (e.g. experimental) for the concept of "normalized power" used in physical endurance training?

Focusing more on the empirical part of the question, consider the link that R. Chung gave in his first comment to Adam Rice's answer. That's the introductory chapter to Andrew Coggan's book, training ...
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  • 19.3k
7 votes

Is it possible to burn only ~850 cal. on 1.5h / 20 km fast bike ride?

Using this calculator we can estimate how much power you needed to produce to maintain your average speed of 20.26 km/85 min: I get 38 W, although I might have some of the conditions wrong. We can ...
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  • 24.1k
7 votes

What applications exist for bicycle power, besides propulsion?

Bicycles are often used for charging mobile devices. A mobile device usually charges with 5 volts (USB) and charging is possible with less than 1 ampere rates -- usually the minimal current unit being ...
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  • 12.4k
6 votes

What is the maximum watt per kg a human can sustain?

Wilson, in Bicycling Science has a plot that's not quite what you're looking for but very close. Closer than it looks at first, I believe. click for full size The downside of this is that it isn't ...
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  • 46.2k
6 votes

Quarq dfour installation

Some cranksets are modular. I'm not sure if this is a standard term, but I do mean that the crankarms fit to the spider with a splined interface. Thus, you can replace the spider. Less commonly, on ...
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  • 19.3k
6 votes

What applications exist for bicycle power, besides propulsion?

A very common pedal-powered device was the spinning wheel used to spin wool into yarn, or flax, or cotton... Then you could use a pedal-powered loom to make fabric, and a pedal-powered sewing machine ...
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  • 1,339
5 votes

What to consider buying a single left side power meter from stages?

I hate to say it, but none of these will work with what you've got The first thing you need to take into account is the crankarm's interface with the bottom-bracket spindle. Your FSA Tempo crank uses ...
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  • 24.1k
5 votes
Accepted

Metabolic equivalent of task (MET) vs cycling power in W/Kg

I am not super familiar with exercise physiology. Nevertheless, I will take a crack at this. METs are used to compare intensity and energy expended across different types of exercise. A MET is a rate ...
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  • 19.3k
5 votes
Accepted

How do I measure my crank-arms?

It's the center-center distance, but it should be stamped on the inside of the arm.
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  • 24.1k
5 votes

How to convert calories to watts on Strava rides?

Every rider will have a different efficiency which will change things slightly, but a commonly used formula that provides a 'good enough' estimate is: Caloric intake needed (kcal) = Watts * Hours * 4 ...
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  • 14.3k
4 votes

Giant power meter left/right balance

Power meters need calibration, even if they have been accurately factory calibrated. This is ideally done when they have reached the temperature of the operating environment. They are based on strain ...
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  • 8,155
4 votes
Accepted

What are (a) the source of and (b) the justification (e.g. experimental) for the concept of "normalized power" used in physical endurance training?

I was very curious about where the 4th power came from. I thought it might be from some fundamental physics and/or physiology, but it doesn't. It's just the result of a curve fitting/regression ...
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  • 131
4 votes

What to consider buying a single left side power meter from stages?

None of the Stages power meters will work with your current crankset. Further, you might upgrade your bike later and you might or might not be able to take whatever power meter crank you get with you. ...
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  • 19.3k
4 votes

What to consider buying a single left side power meter from stages?

As Adam pointed out, none of those options are compatible with your setup. To get something workable you would have to change your crankset. The cheapest option is the main line Claris FC-R2000 with ...
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3 votes

Is it possible to burn only ~850 cal. on 1.5h / 20 km fast bike ride?

It's likely that both the bike and hike calories are overestimates. Many devices use weight and speed to calculate calorie burn, but because they are not measuring any physical output (such as ...
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  • 14.3k
3 votes

Is it possible to burn only ~850 cal. on 1.5h / 20 km fast bike ride?

The 837 "calories" (which I assume mean kilocalories) sounds fishy. Usually when riding at 20.26 km/h speed I use 139 watts of power in varying terrain (10 meters of elevation ascent and ...
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  • 12.4k
3 votes

I have a brand new e bike battery test is good

If the display lights up, the battery is activated and providing the power. No assist from the engine in this case may be caused by: You are in "no assist" mode for some reason. Read the ...
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  • 3,766
3 votes

What is the maximum watt per kg a human can sustain?

I think the answers so far are slightly underestimating maximal w/kg FTPs. I've included a table showing FTPs (and maximal powers recorded for shorter periods of time) from the following site. In the ...
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3 votes

What applications exist for bicycle power, besides propulsion?

Running hydraulic systems (to move winches) on high-performance racing sailboats require a lot of power - and if rules allow bicycle-like setups claimed to allow for more power than hand-driven once ...
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3 votes

What applications exist for bicycle power, besides propulsion?

This example isn't a full bicycle, just pedals. Blockquote In the mid 1920’s Alfred Traeger invented the pedal powered radio, revolutionising communication in the outback. The invention was integral ...
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