Power Meters

by | Bike, Gear

Power Up

if there is one thing that really winds me up it would be too much choice. That seems to be a common issue in modern society. Consumerism is so rampant that everyone seems to have their own specific niche item for sale, each claiming to be ‘the one’. Thanks to websites like Kickstarter, you can now spend literally days agonizing over seemingly similar items that?don’t even yet exist.

Power Meters are something that I frequently get asked about. The question is usually, “which one should I get?”. For the purpose of this article, I will assume you have some understanding that a power meter measures your effort in watts, usually by calculating the amount of strain you are placing on a particular part of the bike. You push hard on the pedal, and that force goes from your pedal to the crank arm to the chainring to the chain to the rear cassette to the rear hub in your wheel. You could measure power anywhere along that path.

Let’s get one thing straight from the start. The best power meter is going to be the one you use most often, is easy to use and provides consistent data. Other than that?it’s simply a chunk stuck to your bike somewhere with a logo on it. Of course, it would be nice if your power meter is accurate. But consistent is more important. If your PM is always 300w out of whack but is consistently 300w out for every training ride, test or race, then that figure is just as usable as one that is perfectly accurate. It’s just 300w wrong.

 

Choice

Power meters come in a variety of types and can be placed at various points on your bike. Pedals,?Crank Arm, Chain Ring,?Wheel Hub. You can now also get an awful looking contraption that sits between your handlebars, measuring air movement?and that has accelerometers on it. It looks awful on the bike, so I would never consider it. It’s called a Powerpod, it is cheap and reports say it works ok, easy to swap between bikes but does not work indoors. And let’s not forget the new Smart Indoor Trainers, which not only have built-in power meters but can also link up to social computer apps like Zwift, in some cases increasing or decreasing resistance as you ride up or downhill on the app.

 

A One Hit Wonder

People who usually ask me about power meters are not the kind to?be looking at a quiver of models to suit specific occasions. They are usually on something of a budget, looking for good value and preferably one power meter that does everything. So what is everything?

‘Everything’ is indoor trainer rides, outdoor training rides and race day. Some people throw a second bike into the mix. A tri bike and a road bike for example. Everything means the power meter has to play multiple roles.

For this reason, a power-based indoor trainer is out of the question (shame, because they are great, as a fairly geeky person and an enthusiastic rider I would certainly add this to my shopping list). The Powerpod is also outdoor only, so for those of us in less sunny climes the indoor season kills the Powerpod usefulness. If you only have enough money to by the Powerpod (I think it is the cheapest power meter) then buy a used version of something else.One thing to note. Other than your computer changing the resistance as some Smart Trainers are capable fo doing, there is no benefit to a power-based indoor trainer than having a standard?power meter on your bike. You can still use power indoors, still record it on your Garmin, still use it in apps like Zwift etc. The only benefit to having a Smart Power Trainer is the ability for a computer program to adjust your resistance as you pretend to ride uphill or go downhill. I still?don’t see the benefit. The more an indoor session sucks the more mental training you are getting.

 

You can never have too many bikes

The next question you should ask is whether you need to use the PM (power meter – I am getting bored of writing it so PM will suffice from now on) on more than one bike. if you need to use it on two bikes or more, then you need it to be transferable as easily as possible. This puts you in the realm of PM wheels or PM pedals. Both of these are relatively easy to transfer in a couple of minutes. The PM sits in one or both of the pedals and measures power there. The wheel uses the hub to house the PM and measure power there.

The downside of pedals is that they kind of force you into using a specific kind of pedal and cleat. This might mean changing the pedals every time you want to ride the different bike, even if you?don’t mind riding without power. Powertap and Garmin are the main pedal PM guys at the moment.

The downside of wheels is that if you want to use your PM you have to use that wheel. This means that you will use that wheel for training indoors, training outdoors and racing. Some people do not want to use their race wheel for training. I ended up having to buy a used disc wheel with another power meter because my other PM was in a lower profile wheel. On the flipside, some people buy the PM in a wheel that they are happy to use racing and training.

Another issue with multiple bikes is compatibility. Your 10 speed PM wheel is not going to run on your 11-speed bike without some messing around changing out the hub for example. If you are going to use a multi-bike setup with your single PM then you need to ensure that it easy easily transferable and compatible across all bikes.

 

A lonely bike?

if you only have one bike then crank arm or chain ring based power meters might be for you. These PM’s can sit attached to the crank arm itself, a little slab of plastic glued to the inside of the crank arm. Some are attached to the chainrings somewhere. Examples are Stages or Power2Max for the crank arm option, traditionally these have been a little cheaper but also a little less reliable – common report of losing connection albeit not for long – a few seconds drop out here and there in the more favorable instances. On the other hand, something like a Quarq chain ring PM will cost a little more but is an excellent, reliable and consistent option.

You can, of course, use any? PM’s mentioned above – pedals/wheel – on a single bike setup.

 

Which one?

Well, the choice really is yours and there is no right or wrong answer. Some people like their Quarq so much they are happy to get the wrench out and get a little dirty as they swap it between bikes. Others put up with a single wheel for training and racing and use a Powertap Wheel Hub PM.

I?will also not go by budget. I’ll let you find your own deals and prices for PM’s are coming down all the time. Whichever you opt for, it has been my experience that you get what you pay for. When the Stages Crank PM first came out it was way cheaper but more frustrating than my more expensive Powertap wheel hub PM. My Quarq DZero was a little more money than others but a nicer and more confident experience overall.

Whatever you choose. A power meter will make a drastic difference to your training and racing. The less experienced a rider is, the more I feel this is the case. I do not preach riding by numbers, but they are a fantastic tool for helping improve a rider and I see almost instant gains as athletes, for the first time, can start to quantify their efforts.

 

No, seriously, which one?

Here are some examples of situations that I think might help.

if you have Multiple Bikes,?don’t mind the?Same Wheels for training and racing then maybe Powertap Hubs / Wheels. They are easy to swap between bikes. get a decent wheel like a Jet Hed 6 and you can happily use it for training and racing. I did the same with a Hed Jet 9. Some people don’t like using an expensive wheel on an indoor trainer though.

If you have Multiple Bikes but want a Different Wheels for training/racing then maybe opt for Powertap Pedals. These will be easy-ish to swap by even the most non-mechanically minded and also mean that your wheels will be cheaper as you don’t have to get a PM in both wheelsets. Garmin Pedals are also an option, I have heard better things about the Powertap and Powertap has been in the power game for a long time. That experience counts for a lot when it comes to accuracy and reliability.

Wanting a PM to use on a?Single Bike is easier. You could go for one of the above multi-bike options to build in some compatibility later on. Or just run with a Quarq or similar. Quarq would be my choice at the time of writing. They cost a little more but are very reliable, nice to use and sync with an app for a few other benefits. You can also use whatever pedals and whatever wheels you like without a knock on effect to the PM.