It’s leg day again. Another bike ride, more efforts, all to get those pistons pumping out more horses than a Ferrari. But what is your effort session really accomplishing? An ego trip powered by a Strava flavoured energy drink or a quantifiable training session, directly increasing your performance?
Don’t get me wrong; a ‘Trophy’ filled ego trip is a great way to build one’s self esteem. But more often than not they are few and far between. Usually occurring at random, but often outnumbered by days of feeling ‘off’, or whatever other excuses you can conjure up. So you felt off and you didn’t get any KOMs. But does that mean your session was a bust? If only there was a way of objectively quantifying your ride.
There is, and it’s called a power meter. It’s not space age, it’s not just for road riders, and it’s certainly not complicated. With my Bianchi Methanol 29 SL equipped with Shimano XTR, the Stages power meter was the simplest and cheapest option for getting power data on the mountain bike. Replacing the non-drive side crank arm, the Stages power meter adds approximately 20 grams over the original crank arm.
But why do I need a power meter? Can’t I just use heart rate? From what I’ve seen in the past few months of using a power meter on the mountain bike, power data is a far more accurate measure of workload. A change in heart rate is a response to mechanical effort as well as external influences such as temperature, sleep and anxiety; it isn’t just affected by the work of the legs. Another response, more specific to the mountain bike, is all those small upper body movements you do to negotiate technical terrain found on the dirt. These small movements push the heart rate higher and can compromise your efforts as you reduce your output to try and get the heart rate back down into the target zone. When you base your efforts on power data, you can more accurately gauge the true workload being expended. This knowledge increases the repeatability and consistency of your efforts so you can actually start improving your fitness.
There is a whole range of other benefits to using power data on the mountain bike. But one that I have been most surprised about is its usefulness on the downhills. I’ve been testing out various Maxxis tyres recently on a local XC downhill and, along with the obvious measurement of time, the power data has given me the chance to really zero in on which tyres were fastest. By comparing the runs with the closest average power and my own perceived effort, I am really able to hone in on what’s the best.
For short races, watching your power meter isn’t really needed. For these races an after ride report on Training Peaks, Strava or the new site Today’s Plan can really help you judge how you paced your race and the exact power of your efforts. But for longer marathon and stage races, with their longer climbs and more sustained power outputs, it can be a big advantage to keep an eye on the your power to save yourself from blowing up. If you’re coming up to a 10 minute climb and you know how much power you can sustain for that time range, you can start the climb just below that number and gradually build up, catching those who went out too hard.
The Stages is a really simple and unobtrusive way to get power data on the mountain bike or any other bike. With a quick swap of your left crank arm, you’re ready to ride. This ease of use is a great selling point for the Stages power meter. Especially when you consider the tinkering and extra parts you need to get up and running with a spider or hub based power system.
Over the last few months I’ve been using it, it has performed brilliantly. A few issues did arise from the battery cover at first though. Two of the small locking lugs connecting the cover to the main device broke off. Without a proper seal some water did get into the device, but an overnight bath in some rice dried it out. Once I got a new battery cover, the water proofness has been great. Even with the new battery cover, I still put the crank arm and Garmin in rice over night after a wet ride. Not because water has entered it, but because it’s better to be safe than sorry.
It’s pairing performance with the Garmin can go into the ‘fine’ category as well. 9/10 times it works but sometimes it has a bad day and drops out. But, then, all the ANT+ devices I’ve used over the years have had their bad moments. One performance issue that has been troubling me is the fact that the Stages only records left leg power. Then doubles it to get your overall power. On the road bike this is a non issue, as most of the time your pedalling away pretty evenly. But personally, on the mountain bike, I’ve found myself pedalling with one leg dominant. One example was on a tight, left hand, single track switchback. To maintain traction I was putting out the bulk of my power through my right leg. It was only for 1 or 2 pedal strokes but it did get me wondering how much of the time I spend pedalling with an alternative power dominance through my legs. Not because of the any strength difference, but because of obstacle issues. This would be my main problem with the crank arm power system.
Overall, I have been extremely impressed by the Stages Power meter. There are a few issues but, for the price, I think it is well worth it. Especially when you consider the simplicity of the overall system compared to much pricier alternatives. If you’re an elite racer or someone who wants to give power a go, the Stages Power meter is a great option. Pair it with a plan from Today’s plan and your well on your way to smashing more KOMs!