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New PM too close to a race?

thekidduxcthekidduxc
in General Training Discussions
I have been riding with a PT for the last 4+ years. Has worked great for me.

I am looking to upgrade my PM to the P1 as it suits me needs better than the PT.

My question is would you switch to a new PM the last 2 weeks of your A race?

IM South Africa is 2 weeks away. This would enable me to use my friends zip sub 9 vs messing with an aero cover. Nothing against the aero cover as I have used one for several years.

Comments

  • Brian HaganBrian Hagan

    David, Is there a way you could ride with both and use two computers for a few rides to see if you can tell the differences?

    I would pair one to TrainerRoad and one to your bike computer and do 5 to 10 minute intervals in each Zone (especially Z1 and Z2) to compare the differences. 

  • Coach RichCoach Rich

    Posted By David Walters on 22 Mar 2016 01:47 PM


    I have been riding with a PT for the last 4+ years. Has worked great for me.



    I am looking to upgrade my PM to the P1 as it suits me needs better than the PT.



    My question is would you switch to a new PM the last 2 weeks of your A race?



    IM South Africa is 2 weeks away. This would enable me to use my friends zip sub 9 vs messing with an aero cover. Nothing against the aero cover as I have used one for several years.

    I would absolutely not change PMs this close to a race. Even a variance between PMs of 5-10w could ruin your race. 

  • thekidduxcthekidduxc
    Thank you. All I needed to hear. Will follow the advice as I would not ride with both.
  • John BayoneJohn Bayone
    You are ready. Don't change anything.
  • thekidduxcthekidduxc
    Thx John.
  • William JenksWilliam Jenks
    I'd change the dual PM suggestion to using them both on the race...with only the old PT on display...just use a different (hidden) computer to collect the data from the P1s just to see what you get. Might be a good way to know how to transition going forward. On the other hand, you can do that any time...doesn't have to be on the race. (And certainly, I agree you should not change to the new PM for the race!)

    PS if both of them are perfectly calibrated, you should get a slightly higher reading on the ones at the pedals, since there have been no mechanical losses up to that point in the drive train. There should be a small loss (1-2%) by the time you get to the rear hub.
  • thekidduxcthekidduxc
    @ William, if I have both PMs running, would I pair one to my Garmin watch and one to my Garmin edge? Would that work?
  • William JenksWilliam Jenks

    Exactly.  You might have to be careful to pair them one at a time, in the same sense that it can sometimes be tough to couple to the right PT wheel if there are a bunch around...pair the pedals first and the wheel while it's mounted on another bike...or even just give it a spin to turn it on, but 50 feet away from your bike if that's easier.

  • JeremyBehlerJeremyBehler
    I agree. When I got my P1s I kept my old quarq and rode the first 4-5 with both feeding separate computers. In my case the numbers were spot on but to the extent they were not (say maybe a pedal vs. hub PM where the drivetrain losses will cause some deviation) it would tell you how much to adjust your numbers with the new PM.

    That said...you should not do anything the last couple weeks before your race. You know your current PM numbers and if something were off during the race you wouldn't know if it's the PM difference or an actual change in your output.

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