I’ll cut to the point. This season I’m weighing in a good 5kg heavier than last year. I’m riding faster, climbing just as quickly …and yet according to my power meter, I’m also producing less power.

What’s going on? Am I more aero now? More efficient? Or is my unit faulty?

A few months ago I replaced my Stages power meter with a Power2Max. It’s a great piece of kit, but the power readings are much lower than I experienced when using the Stages.

It’s possible the Stages was over reading, however the numbers it was giving me seem more in line with what you’d expect was required to achieve the speeds I’m able to do when training.

After contacting Power2Max I’ve put together a few examples from recent rides to try and figure out what’s going on. These include two fast training loops (ridden at a consistent effort to maintain a high average speed), and a longer ride with a hill effort. They’ve said themselves they aren’t sure whether the unit is reading correctly or not. I can send it off for testing but I’m reluctant to as it’s a lot of trouble and I hate faffing with my bike.

Reviewing my findings from below, if the Power2Max really is reading correctly, than on average I’m between 25w and 30w more aero / efficient than most. Which makes sense too in the context of these rides – the quicker they are the further away from the predicted power I get. However it was also true for some climbs I tested. I was around 12w lower than expected on short (under a mile long climbs) I did predictions for when speaking to Power2Max support.

If anyone reading this is really interesting I can provide the original power files for review.


My last three training rides

Here’s a quick kit check. For the first two rides I wore the same clothes, shoes, and accessories for a fairer test. Both rides were obviously done using the same bike.

me-and-bike

Ride 1: Elswick loop

Below is the data from my training ride on Saturday. I’ll also include the Best Bike Split prediction for this loop on that day. Which takes in to account weather, type of bike, rider and hand position, inner tubes, wheel depth, and rim width, amongst many other things! I’ve found it to be a great prediction of effort required for a certain time on a course, and in the past have used it for pacing my Time Trial efforts.

Ride data

Average power: 249w
Normalised power: 260w
Average speed: 23.1mph / 37.1kph

Best bike split predictions

Average power: 273w
Normalised power: 274w
Average speed: 23.1mph / 37.1kph

A substantial difference of 24w. The ride certainly felt a bit tougher than 250w. 273w would feel a lot more like it. That would be around Sweet spot. Which is my perceived effort from the ride if you were to ask me.

Ride 2: Beacon Fell

This was a longer ride with a hill climb effort at the half way point. There was a tailwind on the way out and a head wind coming home. I split my ride into those three laps. Interestingly the Best Bike Split prediction is almost exactly the same average power as the actual data.

Ride data

Average power: 207w
Normalised power: 231w
Average speed: 20.4mph / 32.8kph

Best bike split predictions

Average power: 207w
Normalised power: 210w
Average speed: 20.4mph / 32.8kph

This doesn’t take into account the climb, which is why my NP is higher than predicted. On the climb I recorded 374w for 3:34. But over all it would seem this ride could definitely have been done with the power recorded.


Ride 3: Elswick loop

Below is the data from my training ride on Tuesday. I rode the same route as I did Saturday. A little faster this time. I wore a Castelli San Remo speed suit as pictured.

Ride data

Average power: 255w
Normalised power: 267w
Average speed: 23.4mph / 37.6kph

Best bike split predictions

Average power: 286w
Normalised power: 287w
Average speed: 23.4mph / 37.6kph

Again looking at the data it should in theory take somewhere in the region of 286w for me to ride the loop at that speed. That’s 30w more than it did in reality. That’s a huge difference. It will take a lot of training to find an extra 31w!