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I’ve recently noticed I have a significant l/r imbalance on my bike when on turbo after buying some dual sided power pedals. It’s about 53/47
Thing is looking at the past 2 rides I’ve done outside on the same bike with the same pedals, the balance is bang on 50/50
This wouldn’t be a massive issue if it didn’t cock up all my training zones. Ie outside 280 watts (140 each side) is more like 260 inside (as the right leg doesn’t put out the same power)
Obviously I could knock down my indoor zones, however I’m interested to know why this occurs. I have some hip issues on the right side but that should affect outside as well. Especially given I’m on a tt bike and as such the position is identical (ie I’m not out the saddle at any point and always in the aero position)
Any ideas?
Could it be because on the turbo you don’t need to balance your weight?
I certainly find a turbo hard work, and that’s using a bike I can ride for miles with no problems at all outdoors.
Can’t really comment too much on your imbalance, mine tended to be pretty constant across indoor and outdoor when I last bothered tracking it…only significant changes happened to be over longer rides where I assumed fatigue became an issue.
It’s pretty typical to be able to generate more power outdoors than in, I’m generally about 10% higher outside.
Maybe your imbalance is just one of a number of things contributing to it?
I set adjust my targets down accordingly when I’m training indoors, you’ll know if you’re in the right zone and TSS is only slightly affected if this is something you track.
Comment from Phil Burt about 12 minutes in suggests the imbalance difference isn’t an issue unless it is causing actual problems- ironically uses your exact ratio to say ‘don’t worry’! Unless there are problems I’d give it a few more rides to see if it averages out, you might be looking for significance in the new toy data that doesn’t exist?
As johnnyc (and Phil Burt) said, I'd not call that a major difference (FWIW, my discrepancy on the "real" bike is about that at low efforts but pretty much dead-even at higher efforts)
I suppose if I really wanted to worry, I'd be asking myself:
Are you sure that your outdoor rides are really comparable ?
Is it the same bike? Are they identical in setup
Do one of each avoiding all standing & see if it's your seated power that has the difference ? Then repeat with almost all standing - doesn't have to be for very long
Might your turbo/bike not quite be level ?
How "still" are you when riding on the road - if you bob from side to side a lot, recruiting other muscles, then you can't really replicate that on a turbo (even if it has a rocker mechanism, riders don't tend to bob in the same way - more like the reverse)
If you're on something like zwift, set your realism to 100% and see if that changes anything
(and see if you can get some footage of you on the turbo (esp if it's a different bike) to see there's anything obvious)
All good points. Same bike and position and similar intensity so that’s not the issue.
Not worried so much about having less power indoors, more that my right leg may not be getting the same work out as my left!
more that my right leg may not be getting the same work out as my left!
If it's still working at 100%, who cares?
Might be something to work on to alleviate the boredom on Z2 trainer rides?!
But as above, I’m not sure I’d read too much into it…balance was a curiosity for me when I first had the ability to measure it, but 2 years later I barely think about it.
You could always fo some targeted strength work on the right leg to try and even things out if some of the above show that the imbalance is real.
I always thought that kind of gap was not unusual for power outputs?