Well had an opportunity to setup Peter's 29er...the new Gary Fisher 29er.
The bike setup went really well...tried a few new things in regards to setting up the bike with front fork loaded to take into account the sag in the front fork...I feel this will work well and will report back later.
I have also posted a few shots of Peter riding on Computrainer SpinScan. I have put a few comments on the shots...but basically we were able to improve the dead spots by really focusing on the bottom of his pedal stroke.
Most of us have no problems pushing down on the pedals and generating force. However, many of us could improve the how smoothly we can distribute this force by adding a little bit of pressure throughout other parts of the pedal stroke.
I often hear about lifting or pulling up on the pedal stroke to unweight the pedal..and although I absolutely agree with this philosophy...it is very difficult to get our mind to understand this above 85 rpm...and most of us pedal even faster than that.
So what I like to try and do when starting to get people thinking about how to pedal is the following;
I have them focus mostly on trying to grab power in their pedal stroke just after they pass 90 degrees from top dead centre and attempt to hold onto that power as long as they can (often leading into the upstroke without really thinking about it). I find that this takes some focus off the downstroke...and you can really see this in how a person pelvis moves on the saddle -- it usually gets much quieter right away.
The other thing I notice when I ask people to focus on the bottom hemisphere of their pedal stroke is the heal motion remains in a much better position relative to the ball of the foot -- above it somewhat. In this position you can actually fire your hamstring muscle much stronger to help the back motion that the pedal is traveling in.
If you look at the video below you can see Peter's foot almost remain motionless throughout the stroke...holding the ankle at 90 degrees really helps all the correct muscles fire throughout the entire stroke. If the heel is dropped below ball of foot through bottom of stroke then the hamstring becomes almost weak and unable to pull the pedal backwards losing lots of power.
Likewise on the upstroke if the heel is below ball of foot or less than 90 degrees, this would apply downward pressure on the pedal opposite to the direction it is moving.
The other thing I hope you can notice is how his foot speeds up through the top of the stroke (there is a small acceleration there) ... this is a tough part of the pedal stroke to work on but very important