Power meters

[Jon in Sweden]

I'm quite new to the power meter game and wondered how you other folk with these new fangled gadgets use them in training?

I've got one on my road bike and one on my main commuting bike. Just your bog standard LH crank single sided affair.

Being a numbers geek, I'm really enjoying this additional layer of information. It's incredibly interesting to see just how much of an effect a headwind/tailwind or slight incline will have on any effort to maintain a steady speed. Today (for example), I commuted to and from work wiht precisely the same power output. A modest tailwindwind on the way in, and the opposite on the way back. 2.4kph difference in speed, at 266w.

I am certainly one who's inclined to push too hard, too much of the time. I'm hoping that having the power meter means I'll stop pushing so hard on inclines and try to maintain a steady power output.

Either way, what have been your best and worst reflections and experiences of using a power meter?

[Cugel]

I'm quite new to the power meter game and wondered how you other folk with these new fangled gadgets use them in training?

I've got one on my road bike and one on my main commuting bike. Just your bog standard LH crank single sided affair.

Being a numbers geek, I'm really enjoying this additional layer of information. It's incredibly interesting to see just how much of an effect a headwind/tailwind or slight incline will have on any effort to maintain a steady speed. Today (for example), I commuted to and from work wiht precisely the same power output. A modest tailwindwind on the way in, and the opposite on the way back. 2.4kph difference in speed, at 266w.

I am certainly one who's inclined to push too hard, too much of the time. I'm hoping that having the power meter means I'll stop pushing so hard on inclines and try to maintain a steady power output.

Either way, what have been your best and worst reflections and experiences of using a power meter?

I imagine (never having actually experienced it) that forking out the dosh for such a daft gizmo would be the predominant experience; and the worst/best all at the same time, as you rue the empty wallet but look forward to a gizmo-hit of number-pleasure.

I know, I know - you enjoy the numbers. Myself, I've always relied on my inbuilt power meter, although it works by displaying feelings rather than numbers. It's self-calibrating, though; and always accurate.

[Jon in Sweden]

I imagine (never having actually experienced it) that forking out the dosh for such a daft gizmo would be the predominant experience; and the worst/best all at the same time, as you rue the empty wallet but look forward to a gizmo-hit of number-pleasure.

I know, I know - you enjoy the numbers. Myself, I've always relied on my inbuilt power meter, although it works by displaying feelings rather than numbers. It's self-calibrating, though; and always accurate.

I understand where you're coming from, but as someone who greatly enjoys crunching the numbers and pushing myself, a power meter is really useful.

They actually aren't especially expensive if you look out for Black Friday type deals. You can pay more for a pair of tyres, to be fair.

I think what's interesting is that with power, the measure is absolute and objective. It's not how you feel, it's not about the weather, it's related to, but not fixed to your heartrate. That makes it quite valuable, I think, especially when it comes to pacing up hills.

[toontra]

I find them useful in a nerdy kind of way. I can compare rides against past efforts to see where I am with my fitness, and also compare with indoor training.

I went about it the wrong way. Firstly a left crank for the audax bike (cause it was cheap), but then wanted something for the Cervelo with a different crankset so bought a SRAM-compatible power spider. These both worked well but of course were useless for my touring and MTB's ! So in the end I got some Assioma power spindles and fitted them to a pair of Shimano M520 pedals (which I use on all my bikes) so now can have power on all 5 bikes. If only the Assioma's had been on the market when I started down this road it would have saved a lot of money

[ed.lazda]

... Assioma power spindles and fitted them to a pair of Shimano M520 pedals ...

Interesting. I got some Assioma spindles but all the compatibility information implied they had to be fitted to road pedals, and I've found that I don't really like the road pedals (or, specifically, the cleats). Did you have any problems fitting them, or have to make any modifications? Thanks.

[drossall]

I wasn't bothered about meters and sensors at all until two things happened. The first was a double bypass which led to physio with an HRM provided, and I started wearing at least wrist heart sensors. The second was Covid, which got me into Zwift, and that of course depends on sensors.

I now have a PowerTap wheel for Zwift. I've thought about putting it on a road bike to see what results I get, just to compare as toontra says. But I haven't got around to it. I do have cadence and speed sensors on most "real" bikes now.

I'm not going to spend out loads of money to get power meters on multiple bikes, nor go swapping a single meter around constantly. If they were the price of cadence sensors, probably!

[toontra]

... Assioma power spindles and fitted them to a pair of Shimano M520 pedals ...

Interesting. I got some Assioma spindles but all the compatibility information implied they had to be fitted to road pedals, and I've found that I don't really like the road pedals (or, specifically, the cleats). Did you have any problems fitting them, or have to make any modifications? Thanks.

Very simple process to fit the Assioma Duo Shi to the M520. There's a small tool you need to remove the original spindle - then it's a straight swap. There are a few Shimano SPD pedals that are compatible - maybe a list somewhere online. I tried 2 or 3 different sets and they worked on them all.

[ed.lazda]

Very simple process to fit the Assioma Duo Shi to the M520.

Fitted and calibrated, I'll give them a test ride tomorrow. Very easy, as you say. There is slight play of the pedal bodies on the spindles but I'm not sure that matters too much. I don't know why they don't list these pedals as compatible -- maybe people who use the MTB-style cleats aren't meant to want a power meter

[toontra]

It was a bit of a breakthrough when they released the DUO Shi spindles. Before then people were trying all sorts of hacks on complete Assioma pedals to adapt them to SPD, some more successful than others, but it wasn't straightforward.

There was/is a definite gap in the market for SPD power pedals.

EDIT: Just after posting this I see Favero have just released SPD-specific pedals - ASSIOMA PRO MX-2. Can't find any reviews and only available in Italy atm. The main difference from the spindles from the images I've seen is they've got rid of the large pods - which may also avoid in increase in Q-factor (never bothered me personally). Will look forward to a DC Rainmaker thorough review but I'm happy with the DUO-Shi's for now.

[ed.lazda]

SPD-specific pedals - ASSIOMA PRO MX-2

Oooh, shiny! There's a discussion on the Trainerroad forum, and someone has done a review. If they stay at that sort of price level, it sounds like a "bargain".

[Jon in Sweden]

Does anyone have any thoughts on power versus weighted power? There is often quite a large gap between the two for me on Strava.

So for instance, yesterday's 56km ride had a recorded power of 267w and a weighted power of 290w. It was mostly a fairly steady ride, but there were a couple of bits where I pushed hard (one climb, one wind assisted flat section) for 4 minutes or so at 400w.

From my brief Googling, it seems that larger riders (I certainly qualify for that I think - I've been doing more weight training the last new months and despite an average of about 250km/10-11hrs a week on the bike, I've gained a couple of kilos) can have a larger gap between recorded power and weighted power.

I've no idea really. I'm just curious!

[Jdsk]

Does anyone have any thoughts on power versus weighted power? There is often quite a large gap between the two for me on Strava.
...

Is this a value reported by Strava? And do we know anything about the definition and calculation?

Thanks

Jonathan

[toontra]

I'm quite light, hovering around 70kg, and my weighted power and average power are usually within a handful of watts of each other. Never really dug into the difference. Having said that my FTP is sadly low ATM (225) as I'm coming back from a year of injuries and 3 months totally off the bike following surgery. It may be the higher your FTP the bigger the differential?

[toontra]

Does anyone have any thoughts on power versus weighted power? There is often quite a large gap between the two for me on Strava.
...

Is this a value reported by Strava? And do we know anything about the definition and calculation?

Thanks

Jonathan

According to Strava:

Weighted Average Power
When you ride with a power meter, you'll notice how your power jumps all over the place based on the terrain, grade, wind, and other factors. Weighted Average Power looks at all of this variation and provides an average power for your ride that is a better indicator of your effort than simply taking your average power. It is our best guess at your average power if you rode at the exact same wattage the entire ride.

Looking back at recent rides, Strava has calculated my average weighted power 2-5 watts higher than the actual average power.

[borisface]

Intervals.icu is a decent free site which elevates all your power and HR data to new levels of geekdom. I particularly like the feature where you can compare your peak power records to those of the other users by age, sex etc.