leg drive question

Been working on the leg drive. More specifically matching it to power stroke. 

As the power phase effectively ends once the top hand passes bottom, often called blade passes vertical you start entering exit phase. So the question is should the drive leg have reached bottom by this stage (half way through total rotation), as any further drive during exit phase is not effectively countered by the blade resistance. Any further rotation then being completed with "straight" leg while other knee continues to rise.

I have previously lifted one knee and dropped the other leg at same rate, but that gives rise to the issue of last part of leg drive doing nothing but causing rotation without power during exit phase. This time I have been more forcibly driving and completing wholly during power phase, it feels more powerful. It does tend to cause you to pull/brace other foot on strap to complete rotation. Effectively one knee drops twice as fast as the other rises, rather than that equal cycling motion

However, watching slo mo tutorials like Ivan Lawlers leg drive vid it doesnt seem to be the norm where even Ivan completes the leg drive after blade has gone past vertical. Hope this makes sense

Am I missing something.?

Another issue I was finding is I was often getting cavitation (gurgling) on the left hand stroke. Only shows up in dead flat water on the k1. Turns out this was due to simply not being early and aggressive enough with left leg drive, and as a result not burying the blade firm enough on the catch. This was a byproduct of holding back on a tippier boat. So if you are having this issue and cant figure out why try hitting that leg drive on the offending side harder and see if it solves the issue by putting weight on the blade quicker and keeping it fully buried.

One thing to keep in mind is that the leg drive serves two purposes.  The first is to provide power to the stroke.  The other is to assist in rotating your torso which sets you up for a good catch on the next pull.  So if you see other paddles still rotating during the exit, they are setting up for a good strong catch on the opposite side.

make sense?

I've been working a lot on my technique. Having a device which gives current speed is very useful.

I agree with kwolfe re: leg drive setting you up for next stroke.

Someone, I think on here, said that they had been given a direction to 'pull the off-hip forward'. At the time I didn't think much of this.
Tried it last weekend. 
What a huge difference. Loads more power for same effort. 
Reduces stability a bit, as my pelvis is rotating a lot on the seat. However, it reduces lower back strain and definitely increases the power on each stroke.

Regarding gurgling or plopping blades; I recommend doing stroke drills. Stroke - pause - stroke - pause, etc

Make each stroke considered and strong. Use the pause to set up for the catch.

As the power phase effectively ends once the top hand passes bottom, often called blade passes vertical you start entering exit phase. So the question is should the drive leg have reached bottom by this stage (half way through total rotation)

I think you can see that easily for yourself in a stationary boat or an erg. Have your rotation complete so the low leg is straight and while keeping the core and upper body static past the catch, note where your blade is. I suspect you will find that your blade is past vertical and past your knees making too long a stroke.
My understanding is that at that point your rotation should already be unloaded, your other shoulder and knee going fairly deliberately forward to setup the the next catch. I think it works well with Ian's "standing up on a plate and keeping upright posture". These are pretty key things un my mind as well as the idea of pushing vs pulling.
Note that big O teaches it quite differently. He does note the "forward" aspect of the rotation but he is not strict on the upright-with-slight-forward-lean posture and does teach push/pull combo as opposed just push. 

Did some more drills using this method of fully extending the leg early and realized the major flaw in it. In order to do this the hip rotation breaks from the torso as it is out of sync. So you loose fluidity and power here. However, it does highlight that all the power of the leg drive comes from the initial part of drive, and the later part simply goes into creating the rotation for the exit and set up, rather than a constant drive force. I think Oscar mentions fully extending to touch the hull is really only to ensure that rotation is completed, which makes sense as you dont want the leg loaded as it hits the "stopper"

Actively pulling the hip forward by bracing on the foot strap, even though oscar is dead against this, does help keep the heel on the footplate meaning there is no slack to take up once drive is instigated. It is also psychologically easier to learn rotation when the pull action induces natural "cycling" motion.  I find it helps my stability. In fact I really struggled with balance on a ICF K1 without doing this, though as I get better balance the degree of "pull" diminishes and its more of a toe hook handle brace.

The pause paddle drill is a good one as it is balance related and it is the hesitant balance on one side that prevents putting weight "down" on the blade to keep it buried. A more positive leg drive automatically overcomes this.

Very helpful thoughts guys. Never stops amazing me how tiny nuances in technique make a huge difference to efficient paddling

waverider wrote:  
Actively pulling the hip forward by bracing on the foot strap, even though oscar is dead against this, does help keep the heel on the footplate meaning there is no slack to take up once drive is instigated. It is also psychologically easier to learn rotation when the pull action induces natural "cycling" motion.  I find it helps my stability. In fact I really struggled with balance on a ICF K1 without doing this, though as I get better balance the degree of "pull" diminishes and its more of a toe hook handle brace.

Just make sure you do lots of hip mobility and hip flexor work. Pulling forward from the non drive leg puts a lot of stress on the hip flexor. I strained my hip flexor rowing (which requires a hard pull with the hip to reset the stroke) and doing the technique you mention made paddling impossible. I realised that the technique can be an issue if you do not do the required mobility and strength work for the hips and the flexor.

I hope my synopsis makes sense.

I agree about the need for improving flexor strength.
'pushing' the off-hip forward doesn't require a strong pull on the pullbar. I'm getting that effect and noticing that my off foot isn't even making contact with the bar.

Squats and leg raises are good exercises. I was neglecting those and really felt it.

Stretching and mobility important too.
I (like most paddlers I know) have really tight hamstrings and other bits'n'pieces that attach around the leg-drive area.
Recently, over the past month or so I've invested a good 20 - 30 mins every day properly stretching hamstrings, hip flexors, glutes etc.
It certainly makes a decent difference!