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Questions tagged [power]

Power meters and all related data analysis. 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.

4
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2answers
115 views

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,...
7
votes
3answers
566 views

Understanding e-bike power/torque

In the UK e-bikes are currently limited to a maximum of 250W assistance if you wish to use them on public roads. However, it seems that the motors do vary in terms of the available torque - from ...
2
votes
1answer
91 views

Crank power meter incompatible with my bottom bracket

I have received a 4iiii crank power meter 170mm length that I can't install on my Merida trainer bike because it has square taper bottom bracket. What would be the cheapest way to have it installed? ...
6
votes
3answers
1k views

What is the drag / power lost to a safety flag?

I have a recumbent bike that has a safety flag on the top of a thin pole, so it flutters around higher than and after my head. How much power am I losing to this flag that could be used to power my ...
3
votes
2answers
93 views

Quarq Dfour Fit Problem

I recently buy my first Quarq Dfour power meter to replace my crank Shimano Ultegra 6800. but I have the problem that the quarq spindle its too short ( 106 mm quarq vs 109 mm shimano ultra ). I don't ...
2
votes
1answer
81 views

Can a BB30 Crank Arm (Left) power meter can be used with a BB386EVO Crankset

I have read many websites and articles about the interchangeability of BB30 and BB386EVOsuch as this and this YouTube video. Many say yes and many say no. Yet, I am not sure which Stages FSA power ...
1
vote
2answers
122 views

Rear wheel power spoke pattern

This is my first time posting here. I have been biking for a few years now and learning little by little how to repair my ride myself. My latest problem is 4 spokes of my rear wheel (36 spokes) ...
1
vote
1answer
146 views

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 ...
0
votes
1answer
107 views

Seeking powermeter data [closed]

I am developing a small tool that allows to pick a day for a long cycle trip. The idea is to use weather forecasts to compute how bad/good the wind along the route in the following days is. You can ...
1
vote
0answers
98 views

XTR M960 Crank to Stages power meter compatibility

I want to buy a Stages power meter but my MTB has an old XTR M960 crankset. I wonder if a Stages XTR M980, M985, M9000 or M9020 left arm meter can be installed replacing the left crankarm of my old ...
2
votes
2answers
186 views

Laws against electric assist bicycle with energy recovery? [closed]

Is an electric bike like this required any special license. The power applied comes from the collected kinetic inertia from going down hill or stored from the rider then the stored power can then be ...
1
vote
2answers
505 views

How much faster can my commute be if I use a power meter?

When biking to work, my routes have have stop signs, stop lights, and other interruptions every few blocks or so. My understanding is that if I reach my power at target heart rate soon after stopping ...
2
votes
2answers
615 views

QUARQ DFour installation on Shimano bike

I'd like to replace my Ultegra 6800 crankset with QUARQ DFour powermeter. But I don't know how to choose between BB30 and GXP versions. I have Shimano Pressfit SM-BB92-41B bottom bracket. Do I need to ...
0
votes
1answer
148 views

What target heart rate or power do people use when commuting by bike [closed]

Biking to work is good exercise. It can make it easier to meet our exercise needs. When commuting by bike, what heart rate or power zones do people usually use? What's a recommended target? Should we ...
1
vote
1answer
69 views

I'm looking for a chainring compatible with bb86

I'm trying to invest in a new powermeter (never had one) but my current cranks are FSA Gossamer which are no longer in stock by most. I looked at power2max and they don't have a compact chainring. Is ...
3
votes
1answer
278 views

Does Strava display live watts while biking?

Does Strava display watts from a bluetooth power meter along with a bluetooth heart rate in real time while I'm riding?
2
votes
4answers
169 views

What is the difference between a speedometer and a power meter in terms of performance measurement? [duplicate]

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?...
1
vote
2answers
664 views

Does changing gear relation produce different speed at same applied power?

When you are starting the ride, I potentially believe ("know?") that with a smaller plate(cog with fewer teeth in the rear cassette), you obtain more velocity than with a bigger plate(cog with more ...
3
votes
1answer
376 views

What's the difference between power meter and bike computer?

I am currently using a IpBike computer app (on Android) with DuoTrap Speed and Cadence sensors on my bike. I was reading about power meters and how they would help in training by assessing the power ...
1
vote
1answer
115 views

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 ...
2
votes
3answers
2k views

Estimating FTP from Strava analysis

I bought a power meter. I understand that you should do an FTP test to work out your threshold. But until I have time to do this, could I take a reasonable guess from a recent 35 mile road race? ...
1
vote
0answers
613 views

Stages FSA BB30 Power Meter on Cannondale SI BB30A Crankset

I have a Cannondale CAAD12. It has a Cannondale SI crankset. The frame's bottom bracket is BB30A. My question is, can I fit a Stages FSA BB30 Power Meter on the non drive side? My concerns: BB30A ...
3
votes
1answer
4k views

How to calibrate Garmin Vector 2 power meter pedals with a Wahoo Elemnt computer?

I just installed Garmin Vector 2 power meter pedals on my bike along and am using it alongside a Wahoo Elemnt bike computer. I've done a few rides now and my average wattage is reading very high (i.e. ...
1
vote
4answers
694 views

Big tires are rubbing in certain conditions so how can I fix my rear wheel play issues?

I have a 2007 Tarmac Expert Double with a Mavic Kysrium Equipe rim spoked to a Mavic Kysrium Equipe, 24 hole, Mavic QR rear hub. I recently upgraded to 28mm tires from 25mm and I had the rear wheel ...
1
vote
1answer
234 views

New chain, pedal power seems weaker

I'm a commuter cyclist who didn't for the last 18 months really do anything to take care of his bike - though it was stored inside between rides. Took it to the shop 12 months in for a service, but ...
3
votes
2answers
402 views

Low power while maintaining high cadence

I just started using a Tacx Smart Flow in combination with TrainerRoad to try maintaining and getting up my fitness level over the winter. My problem now is that TrainerRoad tells me to keep a power ...
1
vote
2answers
244 views

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 ...
7
votes
5answers
976 views

What use does a Heart Rate Monitor have if you have a Powermeter?

When should you be riding by HR instead of Power and what can you learn from a HRM when you're riding by Power?
2
votes
1answer
466 views

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....
8
votes
3answers
621 views

Power Output at different Air Densities

Factors Influencing Air Density are: Altitude, Air Temperature, Air Humidity and Barometric Pressure. Calculator: http://barani.biz/apps/air-density/ How does riding at different air densities affect ...
1
vote
1answer
324 views

Speed to power calc on a 'basic' magnetic trainer

I'm a dedicated non-MAMIL, and I enjoy riding indoors on a cheap-and-cheerful 14-speed (max tooth ratio 48->14) attached to a $70 basic trainer while watching the footy or listening to music. No wind, ...
6
votes
3answers
307 views

Increasing stamina while in the office

I started to bike again after 3 or more months of hiatus. I'm currently using a XXS Merida Scultura 300 (I previously used a Trinx R300 needed to upgrade because of the wrong geometry). Thing is I ...
4
votes
2answers
346 views

Calorie Burn Meter Bicycle

Is there any bicycle with calorie burn meter in market? Its not the one on the gym. Normal bicycle for outdoors. Is there any bicycle like that in market? I have a project for my school work. Really ...
3
votes
2answers
143 views

Is the real world experience of riding a light bike understated by physics-based calculators?

Take the case where you have two identical riders, Joe Slo and Billy Whizz. They both weigh 75kg and have identical aerobic threshold power output. Joe has a 11kg steel audax bike, but Billy likes ...
6
votes
2answers
368 views

Power to weight, FTP and Terrain Profile

If two riders of different build rider 1 - shorter, lighter, thinner rider 2 - taller, heavier, stockier Are riding a rolling terrain. No notable climbs. A few short climbs lasting no more than a ...
3
votes
3answers
570 views

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. ...
2
votes
1answer
258 views

Good cycling goals?

Last year I used a power meter, loved the progress and the tool. I am trying to set some power goals for Maximum 5Min and 20Min. What are some good goals to aim? Last year I had 16% increase in ...
0
votes
1answer
575 views

which power meters will work with a sram cx1 group set and a bb90 bottom bracket?

I am thinking about getting a new bike but would like to keep using a power meter but can seem to figure out which ones are compatible with sram cx1 and x1 groupsets. Its for my cyclocross bike so ...
4
votes
1answer
906 views

Will this power2max power meter be compatible with Cannondale Synapse?

I have a 2015 Cannondale Synapse - specifically, this one: http://www.swiftcycles.co.uk/334/products/2015-cannondale-synapse-carbon-105-6-road-bike.aspx. I would like to add a power meter, and ...
2
votes
1answer
95 views

Resurrecting an old style SRM Amateur power meter? [closed]

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 ...
8
votes
3answers
10k views

Combining Shimano RS500 crankset with Stages Shimano 105 5800

I've been thinking about getting a power meter for a while now. I finally decided I would get one, but now I realise that Stages only starts at the Shimano 105 level. I currently have a Shimano RS500 ...
6
votes
5answers
1k views

How do I calculate calories burnt using my bicycle's weight?

I've just finished a long bicycle tour on a loaded touring bicycle, and I'm interested in calculating the number of calories I must have burnt over the trip. However, all the calorie calculators I ...
0
votes
1answer
756 views

Are Osymetric chainring and power2max Classic power meter compatible?

I'm thinking about trying the famous Osymetric chainrings, and I would like to use it with a power2max Classic power meter. I just want to be sure that there are compatible? It's very difficult to ...
5
votes
0answers
112 views

Swain Power-HR relation

I am trying to understand how to use Swain HR to Power equation in my case. Here is a calculator where one can vary the inputs and see the various outputs based based on the equation: http://www....
2
votes
1answer
5k views

Has anyone ever tried to estimate peter sagans ftp and 5 sprint power, if so what would they look like? [closed]

Does Peter Sagan's FTP and 5 second power differ hugely from someone like Mark Cavendish or is Mark Cavendish close in his FTP power range but not world class like Sagan? As Mark Cavendish is 70kg ...
13
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3answers
2k views

What is a power meter and why do I need one?

So I've been looking to become a triathlete soon and I'm hearing all this talk about power meters. Now, upon googling I found vague information which is why I came here. Exhibit A. That article gives ...
1
vote
2answers
1k views

what power did alex dowsett put out during his hour record?

Alex Dowsett recently set a new world hour record of 52.937 kilometres, how much power did he have to produce for an hour to be able to achieve this feat?
1
vote
1answer
124 views

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 ...
0
votes
0answers
314 views

Has anyone else had problems with a Stages power meter at high cadence?

I just started using a stages power meter and it works as expected but with one major flaw so far. When I just did some sprint intervals on the trainer as soon as the cadence went above 150 rpm the ...
2
votes
3answers
1k views

Is there any use to motor pacing for people in the cat 4 to cat 2 range actually useful?

In the local cycling club some people are keen on racing but are no higher than cat 3 in the events that they can enter and the power that they produce. The general consensus is that motor pacing ...