Is my ramp test accurate, or is my power meter getting wonky?

Hi all,
I did a ramp test today, and the improvement seems too good to be true. I’m wondering if my power meter is reading too high.

The result was 316 watts, up from 283 watts only about 6 weeks ago. I’ve been training for about six years, and over the past five years my FTP has ranged from 222 to 283, so this new result seems unrealistically high given my training history. I know this sounds like a humblebrag, but hear me out…

I’m a 51 year old male weighing 73 kilos/160 lbs. A typical week is 350-450 TSS. I’m on a low volume plan and add extra outdoor rides, including zone 2 and Sunday rides with a local team. I added some yoga and strength training into my weekly routine beginning in November.

I’ve been getting Strava PRs fairly frequently and doing well on group rides, so I expected to see an FTP increase. And a 313 FTP seems reasonably consistent with the kind of efforts I put out on the road training last weekend, according to my power meter. But I certainly don’t feel 10% faster than I was six weeks ago, and that seems like a huge jump for someone who’s been training for years.

I calibrated the power meter before starting, but I don’t entirely trust it. It only calibrates via my Wahoo about half the time. (It’s a Pioneer unit, which I can also calibrate via a Pioneer app). I’ve made no changes to my power meter or equipment for a couple of years, and no changes to the ramp test protocol.

I’d be grateful for any advice.


How does the average power on Strava segments you’ve recently PR’d compare to past segment PRs?

The other thing you can try is to find a riding partner with similar weight and a power meter, and climb next to them at a constant pace and see how something like 10s power compares. If the numbers are roughly the same, this would point to your power meter being reasonably accurate. If your power meter shows significantly higher power, then that would point to it being off.

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@SeanInDC are you working out in the garage?

I from time to time consult with parties interested in performing on Zwift & frequently give this simple advice to riders using pedal or left-side power meteres: freeze it before you zero it. If you put a left side power meter in the freezer for a few hours, take it out, zero the power meter, warm up for 30 minutes, then do a Zwift race or a ramp test you’ll see a result that is even larger than what you are observing.

So if you are walking out into a chilly garage where your bike is stored, zero-ing the power meter, then warming up for 30 minutes & taking a ramp test…you might be adding 10 to 15 ‘extra’ watts to your test result if the ambient temp in the garage increases a material amount during the warmup.

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Thanks for the suggestion. The power on a couple of recent PRs read higher than on prior efforts, and in line with the Strava-estimated power of other people who have that same time on the segment.

It’s too icy now to do the power meter comparison you suggest (I’m stuck indoors this weekend ), but that’s a good idea. When I’ve done it in the past, the two devices were close, but it’s been a few months.

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Sounds like things are pointing towards your power meter being in the ballpark of accurate - how’s that for a hedge? :rofl:

Will be interested to hear what happens when you can check against riding partners

I bet this is the culprit. I’m working out on my porch, in 32f/0c temperatures. I calibrated at the start, and I imagine the drivetrain and maybe even the ambient air around the bike (from my body heat—the porch is somewhat protected from wind) warmed up enough to boost the reported power.

Which power meter brand & model do you have? Most modern power meters incorporate temperature compensation for exactly this reason.

It’s a dual side Pioneer. I think the model is SGY-PM930.