Long story short: While doing one leg drills, my right leg that is considerably and consistently weaker than the left. I've been wondering if it is a cleat/fit issue? Or, muscularly this is just the way it's always been and I haven't noticed as I've not done one leg drills before?

Anyone have any insight or experience to share? Just want to be sure I'm not losing out on some power here.

I think it is normal. In soccer I am far more powerful with my right than left--and I think you will always have a "favorite", imo. Though the relative difference should be more narrow over time. When I first started riding I noticed this, but over time both legs became stronger and now they are more closely matched (I think--at least they feel relatively closer in strength while in the same gear/cad.)

I'd feel better about this if I was just starting out, but this is the end of the 3rd year avg 10-15 hours/week year in year out. No noticable difference (left to right) doing one leg extentions in the weight room. Weird.

I have the same thing. My right leg is larger than my left, yet doing OLP it wears out first. Maybe one leg is longer than the other. Put alternate heels on the pedal and back pedal on the trainer. Is the reach the same? Mine are different, about 1/4". In any case, OLP helps, and it will really help your seated climbing power. I've been doing 2 minute OLP intervals for a few years. I think this year I'll try to go to 3 minutes.

It's very common. One of my doctors mentioned that some people have slightly less developed nervous systems on one side of the body than the other, and this causes one side to be larger, stronger, react better, etc. Usually, it's not much of a difference.

Az

I think my left leg is actually shorter by the heel method. I'll get both leg angles measured later today just for s*!tsand giggles.

Knee angles measured the same. Who knew? It looks like I'll just have to affect change the old fashioned way. One leg drills here I come!

its normal, right/left legged just like people are right/left handed. just takes work to get them ~equal.

you should see me trying to do left leg only on rollers, its dangerously hilarious.

It's unlikely to be a fit issues (though if you haven't been fit, it's a good idea). One of your legs is either weaker and/or not as well wired to pedal in circles.

Keep doing the drills, it will get better...