55/45 L/R Power output cause for concern?

A light bike doesn't replace good fitness.

Moderator: Moderator Team

Post Reply
Nikoras
Posts: 67
Joined: Thu Sep 26, 2019 1:59 am

by Nikoras

Hello,
I've gotten myself some fancy new Favero Assioma duo power meter pedals. Readings on my past 7 rides show a pretty consistent trend of 54-56% Left and 44-46%Right split in power. In a way this is somewhat unsurprising given that I had broke my right femur ~5 years ago and the repair process did significant damage to my glute/hip. Though I thought I was fully recovered up until now.

So my question is; Should I be doing something in particular to correct this, or should I just say "Yup, 55/45 is what it is"?

TobinHatesYou
Posts: 5040
Joined: Mon Jul 24, 2017 12:02 pm

by TobinHatesYou

I wouldn't trust those numbers, especially if you are coasting and/or stopping a lot. All of my pedal PMs display ~55/45ish in group rides and races because of the coasting and the fact that the right pedal is the slave. It goes to sleep faster and wakes up slower. On Zwift where there's no coasting and on climbs, my balance is almost perfectly 50/50.

by Weenie


AeroObsessive
Posts: 78
Joined: Wed Dec 12, 2018 7:42 am

by AeroObsessive

Asymmetric power output is only a problem IF it's a problem. The power coming out is largely irrelevant. What is important is the biomechanics behind that asymmetry. For example - if hips are rocking, knee line not straight(ish), excessive ankle flex etc - in general things that will cause undue wear and tear on bone/ cartilage/ connective tissue.

Asymmetry in power outputs is otherwise perfectly normal and usually varies depending on intensity too, ie: the L R variances will differ at low output vs high output.

It should also be also noted that a 50/50 L R balance does NOT ensure sound biomechanics.

sychen
Posts: 748
Joined: Thu Apr 24, 2014 1:06 pm

by sychen

For most parts I don't care about the distribution.
When I rehabbed from a broken leg.. It was really useful for progression and restoration of muscle.

Now that I'm better, just use it if you have drop out issues or battery problems..

55/45 is normal for me.. I'm guessing left would be your clip in/out leg.

Sent from my Pixel 2 XL using Tapatalk


TobinHatesYou
Posts: 5040
Joined: Mon Jul 24, 2017 12:02 pm

by TobinHatesYou

indoor trainer session:
Balance - 49% L / 51% R
Torque Effectiveness - 92% L / 90% R
Pedal Smoothness - 26% L / 26% R

28.2mph 4-corner crit:
Balance - 54% L / 46% R
Torque Effectiveness - 79% L / 74% R
Pedal Smoothness - 24% L / 19% R

I wouldn't worry about it.

Butcher
Shop Owner
Posts: 1019
Joined: Sun Jan 03, 2010 4:58 am

by Butcher

I had an issue with my right leg about a year ago, I do not know what happened but I barely could walk after 20 feet. The pain eventually went away after a month. I got on my bike and wow, the balance was terrible. It took about 4-6 months of riding before I got to see a balanced reading. It does not matter if I'm on a group ride or my trainer, it does not shift much, near 50/50.

Nikoras
Posts: 67
Joined: Thu Sep 26, 2019 1:59 am

by Nikoras

Hmmm the 55/45 split seems to be consistent whether indoor or outdoor for me, but either way point taken. It's also worth noting my right leg is a full cm shorter after the leg surgery.

@sychen yep, left leg is the in and out leg with regards to clipping.

by Weenie


Post Reply