# TT Power - well down on turbo efforts.



## grellboy (21 Aug 2020)

Hi everyone. Just wondering if somebody could give me some advice. Been doing the local 10 mile TT recently. Am better than in previous years but still well down on what I can do on the turbo. I used different sensors for measuring power indoors and out - Stages Power Meter on the road, Taxc Turbo (Flow) indoors - but from reading other posts, the general consensus is that one normally produces more power on the road: Looking at my power curve this is clearly not the case (last 6 weeks average is mostly made up of 10s done on the turbo). Is this due to the rolling nature of the course, or more likely due to vast differences in accuracy between turbo and Stages for measuring? As an aside, during the TT itself and my power fluctuates wildly - again is this due to the rolling nature of the course? My overall effort is 106% - which is roughly in the 105 -110% recommended figures for effort over 10 miles I believe.


----------



## si_c (21 Aug 2020)

Are you using the same bike for the indoor/outdoor efforts - judging from the use of different power meters my guess is probably not. If that's the case and your turbo bike is a road bike and you use a TT bike outdoors then that likely accounts for the different power outputs - position on a TT bike means it's harder to put out so many watts unless you train for that.


----------



## grellboy (21 Aug 2020)

si_c said:


> Are you using the same bike for the indoor/outdoor efforts - judging from the use of different power meters my guess is probably not. If that's the case and your turbo bike is a road bike and you use a TT bike outdoors then that likely accounts for the different power outputs - position on a TT bike means it's harder to put out so many watts unless you train for that.


Actually I do use the same bike, I just turn off the crank power meter when on the turbo and use the turbo's power meter instead. I wonder if it's the rolling nature of the course vs the pan flat effect of the turbo that's tripping me up?


----------



## HLaB (21 Aug 2020)

I wouldn't worry lots of folk, including myself, can get more out on the turbo with regular forces/intervals to encounter and the ability to switch off safely to the elements. FWIW, my eFTP at the moment is 4.70w/kg on the turbo and 4.22w/kg on road. The values have been closer in the past but I just can't push myself psychologically outside to the same degree. Probably because I spent so long limiting myself during chemo. But my indoors power has always been more than outside 👍


----------



## midlife (21 Aug 2020)

Just out of curiosity was your time 26.54 on the road?


----------



## Sharky (21 Aug 2020)

Never had the data or the technology when I was an aspiring TT rider, but I always had a theory that on the days you get the PB's or SB's, you never fully achieve the best power output. Many times, I've beaten my PB or Season's best on a really good night by a large margin and thought to myself that I rode well. But the next week on a really bad night, I would turn out a ride only a few seconds slower then my best, but a lot quicker than all the other rides that season. I must have tried a lot harder on the bad night than on the day I did a PB/SB.


----------



## grellboy (21 Aug 2020)

midlife said:


> Just out of curiosity was your time 26.54 on the road? Officially 26:41. Why, is that really bad?


Er, less than that for actual 10 miles.


----------



## midlife (21 Aug 2020)

Is that my quote, don't recall typing all that?


----------



## grellboy (21 Aug 2020)

midlife said:


> Just out of curiosity was your time 26.54 on the road?


0


midlife said:


> Is that my quote, don't recall typing all that?


Nope, only part of yours. I'm walking my dog in the wind so am blaming that!😂 But, to answer the question, it was on the road but was officially 26:41.


----------



## midlife (21 Aug 2020)

Thanks, I was just confused by the graphs and data lol.  

Back when I was doing 10's it was just a bloke with a stopwatch and a board where your time was written


----------



## grellboy (21 Aug 2020)

Sharky said:


> Never had the data or the technology when I was an aspiring TT rider, but I always had a theory that on the days you get the PB's or SB's, you never fully achieve the best power output. Many times, I've beaten my PB or Season's best on a really good night by a large margin and thought to myself that I rode well. But the next week on a really bad night, I would turn out a ride only a few seconds slower then my best, but a lot quicker than all the other rides that season. I must have tried a lot harder on the bad night than on the day I did a PB/SB.


I normally just blame the wind. Actually I did 60 miles only two days before the TT - nothing strenuous, mostly Zone 2 - but possibly might not have helped.


----------



## viniga (23 Aug 2020)

Can you use the crank power meter inside - just to check what the difference is?

My turbo gives a 10% ish higher reading that my pedals, I always use my pedals now indoors and out to measure the power.

One other aspect is position, are you in your TT position in the turbo, for some (or most) you can't get the same power output when going all aero and narrow.


----------



## Milkfloat (23 Aug 2020)

The Tacx Flow is susceptible to all sorts of errors and dodgy calibration, if you have a Stages then you are crazy to use the Flow for power, switch to your Stages. As well as being more accurate you will be consistent when you are indoors and out.


----------



## grellboy (23 Aug 2020)

Milkfloat said:


> The Tacx Flow is susceptible to all sorts of errors and dodgy calibration, if you have a Stages then you are crazy to use the Flow for power, switch to your Stages. As well as being more accurate you will be consistent when you are indoors and out.


Good idea


viniga said:


> Can you use the crank power meter inside - just to check what the difference is?
> 
> My turbo gives a 10% ish higher reading that my pedals, I always use my pedals now indoors and out to measure the power.
> 
> One other aspect is position, are you in your TT position in the turbo, for some (or most) you can't get the same power output when going all aero and narrow.


Good idea! See below.


----------



## grellboy (23 Aug 2020)

Milkfloat said:


> The Tacx Flow is susceptible to all sorts of errors and dodgy calibration, if you have a Stages then you are crazy to use the Flow for power, switch to your Stages. As well as being more accurate you will be consistent when you are indoors and out.


Good idea. Tomorrow morning I'll switch to the Stages....and prepare for a big dip in watts! 😂


----------



## grellboy (24 Aug 2020)

Well I took your advice and turned on the Stages for measuring power rather than use turbo stats. Done two 5 mile efforts for comparison, one using turbo the other the Stages. About 6 seconds difference in time, a tenth or so difference in average mph....and 22 watts less in power! Am pleased though because the next time i do a TT at least I'll be able to put more faith in my FTP% being accurate. Thanks everyone.


----------



## HLaB (17 Jun 2021)

Digging up this old thread. Apparently a lot of turbos read higher than power meters and its a marketing thing, 'the users of our turbos are uber strong', 'this turbo must be good my FTP has went up 50w' etc


----------

