New powermeter with an upcoming ramp test

Hi all, Im in the middle of a training plan and have a ramp test scheduled for tomorrow. I recently purchased a new bike and it came with a left side 4iiii powermeter. I plan to move to using the powermeter rather than virtual power as from what Ive read it’s the better choice and I’d like to be able to have my power readings consistent between indoor and outdoor workouts.

My question is on this upcoming ramp test should I switch to using the 4iiii meter or stick with virtual power. I like to see the progress I’m making and I’m not sure I’d be comparing apples to apples if I switch in the middle of a training plan as my previous ramp test have been using virtual power. I’m on Saris H3, if that makes any difference.


no better time than now - you would have to retest sometime in the future when you switch


Switch to the power meter. 100%, no question. Switch. Be prepared to see different numbers on ramp tests…don’t sweat it. The power meter is a more accurate and consistent measurement device. Switch.


Can you dual record using both virtual power and your new PM? I would do virtual power as you have in the past and have your pm record to your head unit.

If there is a difference between them this is a good time to understand what it is. If you had a gain it will be nice to know. Use the PM going forward.

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I haven’t played around with it at all. I didn’t know there was an option to dual record. Ive tried to use the whaoo head unit for this purpose but it senses that I’m not moving and pauses the ride…

I appreciate everyone’s quick responses. Sounds like I will be making the switch. The dual recording options sounds awesome as I could still compare to my previous efforts, does any one have any more info on this. Sorry if this questions has been previously addressed I’ll search and see what I find.

Unfortunately virtual power is useless outdoors so I would agree with others to switch over to the power meter. The number you get on the test will set you up for continued progress and then you can more easily take the workouts outside and continue to get faster.

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Went through this exercise a bit over a year ago. I did the ramp test in virtual power, but had my new power meter running on another platform (zwift/etc). i noted the improvement but manually set my new FTP based on the new power meter.

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I misread your initial post and if you are using an H3 you have a very accurate PM. I was thinking virtual power like you get from a dumb trainer where TR uses an estimated power curve.

Your H3 is measuring at the rear hub so it is giving you left and right power. Your 4iiii will just measure the left side and double it. No one is 50/50 balanced all of the time and balance is not always static and may change at different power outputs.

If it were me I would like to know how things compare between the H3 and 4iiii, the H3 will be the better measure of your total power.

Pair your 4iiii to your Garmin. If you have autopause turned on it may be why the Garmin stops on you since it doesn’t sense any movement. Garmin also has an indoor profile you can use which turns off GPS.

4iiii is good but understand there is a difference between single and dual sided measurement. You can also look into turning on powermatch in TR.

Didn’t consider the autopause, that makes total sense.

Could you share the results after you’ve done the test? I’m quite curious how it’ll work out for you.

Its important to note the difference in precise vs accurate. H3 might be precise, but accuracy is relative when it comes to PMs, since they all kind of only are accurate in relation to themselves (since we don’t know absolute value…)

With that said, I agree with many above to start using your 4iiii. For the sole reason that you want to be able to compare inside and outside values, and for that you should use the 4iiii inside as well :slight_smile:

So inside, use PowerMatch, so it takes the power from the 4iiii.

Since you are doing a Ramp Test, its best to start now. A good time, since you then will get a new value to train at that is based of the new PM.

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If there’s a significant difference between the saris and 4iiii his progress levels. I think the best option would be to dual record, accept the ftp from the saris then note the progress levels then manually adjust to the ftp ftom the 4iiii and if progress levels change ask support to restore them to the previous levels

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I have a Saris H3 and a 4iii power meter.

I recommend you switch to the power meter. I ended up doing this because I had no choice (blew up the motherboard of my H3; had to use a dumb trainer waiting for the warranty repair), but I am now back in business and am really happy using Power Match.

Fair warning that, at least in my case, I had a pretty dramatic variation between the 4iii readings and the Saris. It was humbling at first, but I feel confident I am now using a power meter that goes where I go. :slight_smile:

And be sure to take the ramp test! This is no time to use the AI FTP detection.

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As suggested by others, the first thing I would do is compare your H3 and your 4iii. I tested three power meters a while back because I was getting strange results from my over optimistic Tacx Vortex.

The H3 is high quality unit. I’d suspect that your power may be close on both power meters.

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I think I’m going to do the test using the powermatch feature and letting the 4iiii control the H3. I’d like to dual record to see what the difference is between the two however I don’t think I’d get anything all that useful out of it as I plan to use the 4iiii as the powermeter moving forward.

If I did the test and tried to dual record (H3 & 4iiii having the H3 act as the powermeter for the test) I don’t kow the algorithm to get my ftp. I’ll have the data from the 4iiii but I’m not sure how trainerroads algorithm calculates ftp as it relates to power and time on the ramp test. Hope that makes sense.

I’m not sure how I’ve managed to make pedaling a bike so complicated… For now the is plan it to do the test using power match as this is what till be using moving forward.

From Trainerroads website

How PowerMatch Works

PowerMatch allows riders to display and record power readings from their power meter and still benefit from the automatic resistance control of their smart trainer. It lets riders get consistent power readings from their power meter both indoors and outdoors without having to give up the benefits of their smart trainer.

Put simply, PowerMatch will use the power readings from your power meter to control your smart trainer. TrainerRoad will measure the power offset between your power meter and smart trainer and will adjust the resistance of your smart trainer based on that offset in power and the current interval target.

PowerMatch will work with any smart trainer that works in ERG mode with TrainerRoad.

You can start off with a simple test outside of TR.

  1. Get the H3 on some device - phone, their app, whatever will control it and show power.

  2. Get the 4iiii on another device or app - garmin head unit, whatever you normally record on.

Calibrate both the H3 and the 4iii after a 15 minute warmup. You want everything up to temperature.

Now just ride steady - 100 watts, 125, 150, 175, etc. 3 second smoothing might help on your head unit. You’ll quickly see if they are close or way off.

If they are close then you’ll know that whatever ramp result you get from the 4iiii would have been in the same ballpark.

If they are way off, it will be good to know why your FTP went up or down by 30 watts just so you can mentally calibrate things going forward.

I wasted months futzing around after I got my Stages. I thought my Stages was defective! My not so smart trainer had been reading 20-30-50 watts higher. Had I realized this initially, it would have been easy to move forward with the Stages.

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So I just completed the ramp test using the 4iiii as the powermeter. This is my 3rd ramp test and the two previous tests have been using the H3 as the powermeter. First test I got a FTP of 250 second test FTP of 254 and on this third test using the 4iiii I got an FTP of 270. As much as I’d like to chalk this up to the hard work I’ve been putting in on the bike I know more than a few of thoes watts are due to difference in the powermeter.

For context the AI deal trainernroad has that will estimate your FTP rather than having to do ramp test was putting my FTP at 262.

After the test I recorded some data on the wahoo which recorded the 4iiii power and controlled the H3 through the Saris app. I did 2 min at 150 watts 2 min at 200 watts and 2 min at 250 watts. Here is what was recorded.

Not sure if there is anything to be gained from these images but here are some screenshots of the whaoo data vs trainerroad data


Accept the AI FTP of 262, let it reduce PL levels accordingly, record those PL levels, now manually set FTP to 270 if your PL levels change contact support to set PL levels to recorded. Now move forward using your 4iiii PM only