What is power actually measuring?
Put simply, it’s the work you’re doing (the force produced by your muscles) per unit of time and is displayed on your bike computer as watts (W). It isn’t influenced by external variables, so provides a very definitive indicator of your output at that exact moment and is measured using a power meter.
What is a ‘good’ power reading?
It’s hard to put a number on this, as you (yep you, sat looking at this screen) could be a novice, 85-kg male or an elite, 68-kg female; so, we’re hanging around in how-long-is-a-piece-of-string territory. However, as a general rule of thumb, a typical commuter might pedal along at around 100 W, an enthusiastic cyclist who’s regularly out on the bike will be looking at numbers in the range of 150-250 W for a weekend ride and the pros will be crushing mountain stages at around 300-350 W...for 6 hours.
What’s an FTP test?
Without performing some baseline testing the numbers from your power meter are as useful as a chocolate fireguard. Therefore, to get the most out of their power meters and, more importantly, themselves, people often perform a Functional Threshold Power (FTP) test, which establishes a baseline and training zones. There are other types of test, but this is the most common.
The FTP test can be completed in a number of formats (8-, 20- or 60-minute duration), either indoors or outdoors. Many people choose to do it indoors, as the environment is completely controllable and if you predominantly interval train indoors, then this would be the optimum choice. If you often train out in the wild, it is possible to do an FTP test on the road, but you need to find a stretch that enables you to get your pedal on largely unhindered.
The beauty of the FTP test is that it is a repeatable, time-efficient way of tracking your progress. If you’re disciplined enough to repeat it (or you have a coach prescribing it in your programme) you can evaluate your progress and adjust your training zones ensuring you’re optimizing every ride.
How often should I do an FTP test?
Testing needs to happen often enough to keep your FTP value up-to-date, so you’re always working at the desired intensity for maximum GAINS. However, the FTP test is somewhat stressful so the general consensus is to aim to do one every 6 weeks. You will see improvements over this period so it’s an awesome way of quantifying that progress.
What am I looking to compare when I’m deciding which power meter to buy?
Strain Gauges: These little strips of metal detect the forces being applied to the bike. In the InfoCrank, they are bonded in places where only the tangential force (the important info.) is measured by detecting microscopic deformation. This force is then displayed on your head unit as power. In other brands of power meter, strain gauge placement differs, which means other forces, such as flex in the crank arm or ‘noise’ in the chain ring, are detected and an algorithm has to account for these surplus force readings.
Compatibility: Power meters disguise themselves as many things: Pedals, cranks and hubs, and the type of bike(s) you ride may also influence your choice. Check with the manufacturer that the one you select can sit happily on your steed. With the correct bottom bracket, the InfoCrank can go on any bike.
Battery Life: This ranges from 300-350 hours. Most power meters have user-replaceable batteries, so always travel with spares and you’ll never be caught short.
Manual Zero Offset: This is a pre-ride calibration check that most power meter companies require; for InfoCrank, it isn’t necessary.
Weight: Power meters range from 20 to 300 g. If you really care about weight then you’ll want to consider this during your decision-making process.
Why are they such different prices?
As with most things in life, you get what you pay for. Power meters are complex pieces of equipment, some more so than others. The price will vary depending on how much research and development, and engineering has gone into producing the power meter. The better the engineering and the materials, the longer the power meter will maintain the quality of data, which is reflected by a higher price point.
How easy is it to fit an InfoCrank?
If your bike has an existing Shimano bottom bracket in it, you just need to remove the existing crank and the InfoCrank Classic (24mm spindle) will fit right in. All M30 (30mm spindle) InfoCranks are provided with a new bottom bracket and we recommend that you take it to your local bike shop to install.
With an InfoCrank Classic you need to do the following:
- Remove your existing crankset from your bike.
- Clean and re-grease your bottom bracket making sure it’s smooth.
- Attach the chainrings to your InfoCrank and make sure the bolts are tightened to the correct torque.
- Slot the right-hand crank (with chain rings) into the bottom bracket, making sure that the chain goes around the crank correctly.
- Use the supplied spacers for the left-hand crank to make sure there is no play or movement in the crank.
- Tighten the left-hand crank using an 8-mm allen key.
- Ensure the crank is tight and that there is no sideward movement. If there is, you may need to add another spacer.
- Connect your InfoCrank with your bike computer by riding outside (simply turning the pedals will not work) and searching for it as a new device (in the same way that you would a speed sensor or heart rate monitor).
- Calibrate your InfoCrank in the device setting on your bike computer; to make sure the reading is '0', you may need to do this a few times.
What’s the benefit of going for a crank-based rather than a pedal-based power meter?
A crank-based power meter is arguably more accurate. The position of the strain gauges (in the tangential load path) results in detection of only the forces that propel you forward. Whereas, a pedal-based power meter will also detect axial load, side load, pedal axis torque, crank axis torque and side torque; all of which are not useful and require computing out.
I’m more of an endurance athlete, do I need a power meter?
YES! Training with power isn’t all about smashing short intervals ALL. THE. TIME. It’s about precision and consistency, measured efforts and intelligent recovery. All of which you can achieve with the help of a power meter and a training plan. A power meter will ensure you train hard enough to improve, but not so hard you can’t go again the next day.
Can I compare my power data with someone else’s?
You can, but you need to do a little bit of maths. As nice as it might be to parade around telling everyone your maximum power output, it’s irrelevant information unless they’re the exact same body composition, height and weight as you. WHAT ARE THE CHANCES?! So, if you do want to compare, you need to establish your power-to-weight ratio. To do this, divide your maximum power output (in W) by your body mass (in kg). WAIT, that’s not all though, you can calculate a 5-sec, 1-min, 5-min and 20-min power-to-weight ratio, which will indicate who, out of you and your gang, can best bosh out a sprint or fly up the hills.
What’s the difference between power and heart rate?
In short, your heart rate will tell you how your session went, your power will show you how your session is going.
Heart rate indicates the physiological stress you’re under, but is influenced by various factors, including temperature, fatigue, illness, point in menstrual cycle, hydration … meaning that it fluctuates significantly day to day. Heart rate, as a type of feedback, also lags behind a bit; you may have got half way up a steep hill before your heart rate catches up and lets you know you are in fact blowing out your arse. However, it does provide a really useful picture of your overall fitness improvement over time (indicated by a reduced resting heart rate).
Power is the work you’re doing (the force produced by your muscles) per unit time and is displayed on your bike computer as watts (W). It isn’t influenced by external variables, so demonstrates a precise indicator of your output at that exact moment.
In an ideal word, you’d use both measures concurrently.
How do I access the information collected by my power meter?
Once you’ve dried the sweat from your brow and strewn your Lycra across the floor, you’ll be able to sync your power meter data to a training application of your choosing via Bluetooth or ANT+. You’ll then be presented with graphs, maps and tables, which you and anyone interested can analyse to ensure your training is going in the direction you want.
What is the best way of analysing the data and making the most of my power meter?
Data collected from an InfoCrank can be analysed in various ways. If you have access to a coach, they’ll be able to advise you on an appropriate training plan to achieve your goals. Carrying out an FTP test (or similar) will give you an idea of your baseline power output and power zones.
Although most of the apps that come with cycling computers allow you to see the data, popular programmes for data analysis are Strava and Training Peaks. Of the two, Training Peaks offers more in-depth breakdowns than Strava.
My left/right balance is never equal, should I be worried?
It’s quite rare for someone to record a 50/50 L/R power balance during a ride, so if the difference is within 1-3%, there’s no need to fret. However, consistently showing a preference in one side of >3% may indicate a weakness or tightness that could eventually lead to injury, so do keep an eye on it.
If I’m always using the same power meter, my power readings are accurate relative to me, so it’s still useful, right?
If you don’t have accuracy, you can’t have consistency. Many manufacturers are happy to peddle their power meter stating that it is only accurate to +/-2%. These power meters also require regular re-calibrating/zero offsetting and are prone to data drift when the temperature changes. Put very simply, this means 230 W measured one day, might not be 230 W the next day, even if you’re using the same power meter.
The InfoCrank has been certified as accurate (max. error of 0.2%) using dynamic testing and was commissioned by the Australian Institute of Sport to ensure the accuracy and consistency of the power data obtained by their athletes. The dense housing of the strain gauges means they are not subject to temperature fluctuations and the InfoCrank never needs re-calibrating. The InfoCrank is the most accurate (and therefore the most useful) power meter available.
What are the benefits of training with a power meter?
You’re taking the guesswork out of your training. Following an FTP test, you have all the information you need to optimise your training every single session. The power meter will prevent you from pushing too hard or, alternatively, it will ensure you’re hitting the intervals hard enough. It’ll also show you improvements over time (which we ALL love to see).
In addition, information such as left/right balance, might highlight a weakness, which could indicate a poor bike position or a potential injury. With data analysis and a bike fit, you could make your riding more comfortable, more efficient and so improve your power output, without having to work any harder.
A final benefit is monitoring your freshness. The data will show you if you need to take a rest; last week you were rolling around at 200 W no bother, this week it feels like you’re struggling. The power meter will help you to see if you need to have a rest.
The key to success is always training smart, not necessarily hard.
Are InfoCranks just aimed at super serious amateurs and professional athletes?
They’re aimed at anyone who understands the value of having an accurate power meter. If you want to see genuine improvement over time, whether that be making your annual trip to the alps less arduous and more awesome or your position in the local road crit league 10 places higher, then you need to have an accurate tool to measure your performance. A power meter is an investment, no matter what level you ride at, but one that will reap huge benefits for anyone that chooses to train with one.
What do all the different abbreviations and sizes indicate (BCD, PF30, 24/30 mm, OSBB …)?
- BB - bottom bracket
- OSBB - oversized BB
- BCD - bolt circle diameter
- PF - press fit
- 24/30 mm - size of the spindle
- 155-175 mm - crank arm lengths
The InfoCrank is compatible with most bike frames, if you’re unsure what your bike needs, contact us and we can help you out.
Does it only fit a specific bottom bracket?
Your bike frame needs to have one of these options:
- ‘Standard’ BB30 (42 mm plain bore with no intrusions x 68 mm wide with the circlips)
- ‘Standard’ PF30 (46 mm plain bore with no intrusions x 68 mm wide)
- Accepts OSBB and does not have a preinstalled bottom bracket. Inner shell must be bare
- English threaded 68 mm wide BB
How long do InfoCrank batteries last?
Approximately 350 hours. The batteries (4 SR44 silver oxide batteries) are easily attainable and you can replace them yourself; however, not all batteries are made equal. To optimise your InfoCrank, Renata batteries are the best option, so head to our Tuck Shop to top up your supplies.