Powertap P1 pedals
I raced Wisconsin and have Louisville coming up. I neglected my gearing on the Wisconsin course, and didn't want the same mistake for Louisville. So I swapped my Quarq 53/39 172.5s for my original cranks 50/34 165s and purchased power tap p1s. I figured I had a few weeks prior to race to work out the bugs etc.
Since setting it up on Zwift, I have been running my Kickr power to the Apple TV, and the pedals to my Wahoo bolt so that I can compare numbers etc. I downloaded the power tap app, and made sure firmware was up to date, AND that I set my crank length appropriately in the Bolt and on the app. I am zero-ing my pedals before every ride.
Prior to this I would occasionally run my quarq to my Bolt to compare my numbers for future racing/outside comparisons. The quarq numbers were usually within 2-4W of my Kickr.
Fast forward to the current setup....my pedals are reading 20-22W LOWER on my bolt than my Kickr is reading on my ATV. I knew meters can differ but by this much?? And now that I'm so close to the race, how do I rectify my numbers for race pace etc? I feel like I've just shot myself in the foot LOL. Do I just take 20W off my goal and go with it?
Comments
@Jeff Horn That's typical for me on the same set up, when I'm using my KICKR on Zwift. I use the same P1 pedals on my trainer bike and my TT bike, and find an FTP of about 212 outside on the TT/P1s, and near 232 inside on the trainer/Zwifting/KICKR.
Protocol would say that you should NOT be using your indoor FTP when planning for outdoor racing - two different beasts, to say nothing of the potential difference in power sources. Do you data from race rehearsals with P1s, to help you zero in on power targets for race day IM LOU?
Thanks @Al Truscott I do majority of rides even race rehearsal indoors. That has all been with the KickR. I think what I'm going to do is correlate my 0.68IF power number to the P1 number (175 on KickR to 159 on P1 for instance and hang around that number)
@Jeff Horn I would have said the same thing as Al but seeing as you ride indoors most of the time can we get some other metrics to help determine the numbers.
As for the 20-22 watts difference I can't say if it's common between the two power metres and I would not care as long as it's a consistent measure. Yes your power number is lower but if you are actually getting the same amount of force on the pedals as the quark then it does not matter.
DC rainmaker's review for 2016 for the kickr2 seems have the p1 pedals reporting below the kickr but not at the level you are seeing. His review of the pedals from 2015 say they are consistent.
Do you have any data to help with your outdoor versus indoor FTP? I can typically get more watts outdoors than on the trainer.
With only 5 weeks between the two IM races what is your longest ride on the P1's. What does that data look like in comparison to IMWI rides with the Quark?
Without any further input I'd say you are correct is going with the .68 number of 159 for the P1's.
Thanks @Gordon Cherwoniak . I generally use my indoor FTP as my outdoor and racing benchmark. This is an error that I would love to correct, I just prefer not to ride outdoors much anymore. Longest ride on the p1's is 2 hours. NP on Kickr was 208, P1 was 189. I'm thinking about changing the crank length in my head unit back to 175 to see if that gets the number back up closer to KickR number.