Which Power Meter Should you buy for your Bicycle: PowerTap, Quarq, SRM and Power2 Max
Choosing the Right Power Meter
Picking the right power meter for you is important. Making the decision might not. We break down the Pro's and Con's of each device and give you our top choice for your first step into diving into the world of Power Based training. We rank the devices base on Cost, Accuracy, Weight and Ease of use to help narrow down the list.
Power 2 Max Power Meter
Cost: $950 to $1464.33
Power 2 Max has the most economical of the crank based power meters. You can buy just the sensor(something other companies don't offer) and add it to a compatible crank set. Or you can chose from a myriad of their all in one crank and sensor options. This gives you the flexibility to also chose your BCD diameter and your crank arm length. Great for some one looking who is still budget minded and wants a versatile crank base power meter.
Accuracy: +/- 2%
Power 2 Max also has amazing accuracy ( as reported by their own marketing) a +/- 2% is amazing and well under the biological variability of our bodies. This make them excellent tools for both training and testing.
Adding between 172-224 grams (depending on which model sensor you choose) the Power 2 Max sensors are extremely light for the added benefit they provide.
Ease of Use: Unknown
It's hard to say exactly how easy the Power 2 Max meters are to use. The main things to be concerned is they are primarily a European market base company and any warranty and service issues may cost a great deal in time and money should something go wrong. They do however boast the same auto-zero calibration as the Quarq meters and work with any ANT+ Computers.
Cost: $ 1,799.00 - $ 3,995.00
SRM's are not cheap, mostly because you have to but it with a crank set and can't just buy one that you can install to a compatible crank set. Be that as it may, this still makes them more expensive than Power 2 Max complete sets.
Accuracy: +/- 2%
SRM is know to be the first power meter to hit this elusive accuracy mark, since then Quarq and Power 2 Max both boast the same accuracy profile. The two percent variation is more than adequate and beyond your body's biological variation of power output.
While you will have to choose which crank set you wish to have with your SRM, the actual sensor itself only adds approximately 195-200g of weight. This put's SRM in a slightly higher range for weight but still under the highest amount a Power 2 Max sensor might add.
Ease of Use: Poor
Under SRM's own guidelines, they suggest you ship your power meter back yearly to them. This is the only way you can re-calibrate your sensor. This works well for the dozens of professional teams they sponsor, since the device will be professionally handled, chances are the professional racer has a 2nd back-up sensor and it's guaranteed to be free. This is just their suggested idea, there are many things than can cause your sensor to need to be re-calibrated and potentially could happen any time. For many this extra potential for a head ache inducing hassle makes the idea of buying an SRM completely not worth the risk. Not to mention if you are not aware of how much the sensor is out of calibration you could potentially have hundreds of rides worth of useless data, and thus defeating the whole point in using a power meter to train.
SRM does have a great reputation for maintaining durability and rarely needing more than a yearly re-calibration. Even in events of needing re-calibration the variation is minimal and most users data are perfectly intact.
Cost: $899.00 - $1,799.99
PowerTap hubs were some of the first major players in the market for wireless power meters. You can even watch some old Tour de France stages and see them in the rear hubs of many of the top cyclist. Cycleops provides a few different types of hubs you can buy even a myriad of options to have them already laced into a wheel or wheel set. Albeit the latter option is extremely expensive. At $899 PowerTaps are one of the cheapest options to get into training with power.
Accuracy: +/- 1.5%
Cycleops improved the accuracy for their hub recently and reached unheard of numbers. Does the extra .5% accuracy matter? No. Does it cost more? No. Will you even notice it? No. It does add some extra bragging power to using the device, but ultimately will not make much difference in your everyday training.
Heavy, that is what they are. While you can subtract the weight of a conventional hub from them, and they technically become comparable to the other sensors on the market, this is extra rotational weight. This make their weight weight slightly more than a crank based meter. Since hub weight is not as centrifugally as heavy as rim or tire weight, it's not something to be all that concerned about, since at low speeds going uphill when weight matters, your wheels will be rotating slowly. Plus can't we all cut an extra pound or two of body weight?
Ease of Use: Fair-Easy
PowerTap's are easily serviceable by the user. Re-calibration can be done from easily using an ant+ device or their own bicycle computer. While Cycleops has certain standards for what is an acceptable amount, very few devices need ever be sent in for a warranty calibration issue. Calibration usually take 2-5 seconds and you are ready to ride. The down side to using a PowerTap is to have multiple sets of wheels, of training on your pricey race wheels all the time. You will not want to not have your race day data, it is the most important data for analysis.
Another know issue, is that the free hub is very open to the elements, water and grit can find it's way into it. On the positive side, once you remover the rear skewer you can remove the hub using just your hands, with no tools. You can also easily clean and grease your hub yourself with no need for a professional. PowerTap's are also the only device that you do not need a tool to get at and replace the batteries with. Cycleops does make a special tool for this, but if you have a rubber bottle cap opener, you can simply twist the cap off with your hands. It will also cost much less, and is even safer to the aesthetics of the hub.
Cost: $1595.00 - $1995.00
Quarq provides countless other crank options, but since they are owned by SRAM the cost show is for the Quarq and SRAM Red variants. You can if you want add a quarq to other crank sets as well.
Accuracy: +/- 1.5%
Quarq matches the PowerTap in accuracy. Much like the PowerTap though, this extra .5% will not make a huge difference in your training at all. It's best to just take comfort in knowing that your power data and numbers will be as accurate as possible.
When comparing the weight of the SRAM Red crank set and the SRAM Red Quarq crank set, the additional weight is only 169 grams. This makes the Quarq sensor the lightest you can buy.
Ease of Use: Easy
Calibration is done in a more complicated way than the PowerTap, but in a simpler way than an SRM. Quarq makes an app for that. You just need an ant+/bluetooth type adapted and you can easily calibrate your Quarq yourself at home. Much like the SRM, Quarq sensors do not need to be calibrated often, and when they do the variation is minimal.
If you've made up your mind and are now taking the plunge into training with power. There are plenty more bits of information you will need to learn about, like the Performance Management Chart and how to use it to maintain top form and control your fitness. Before you even begin you will need to take one step, the very first thing you need to do is find your Functional Threshold Power. Just click the links to find out more.