Originally Posted by
BHOFM
On close inspection of the video, it looks like you have your foot
way forward on the pedals. The ball of your foot should be just
to the rear of the center.
This takes the strain off the knees and makes your legs just
a bit longer on the down stroke. Like the push you get from
the toes when running.
Try running on your heels sometime and you will get
the message.
As in:
You can also hit the back of the front tire with
your foot if it is too far forward. This is not good!
I disagree with this advice. Many studies show pedaling with the foot in the middle of the pedal is more efficient. I will cite as an example of when you do a squat, you don't push up from your toes, you push up from the heels. Regarding running, there is nothing wrong with being a "heel striker" look at modern footwear, look at how much padding is on that part of the shoe. In the case of running you will absolutely be faster having a flat to slightly toe striking pattern when doing distance running, but you can run perfectly fine and healthy as a heel striker and more people get hurt running on their toes from straining their calf muscles.
regarding tires, what size tires are on the bike, if your 400lbs and only running 80psi, I hope you have 700x35 tires on there. one thing that sets apart cheapo tires from mroe expensive ones are the ability to take higher pressures. AS a 250lb rider, I've had to be careful when buying road bike tires because I really need at least 125psi in the rear wheel of my 700x25c tire yet many tires that size are only rated to 100ish. you can go over it a little but generally i won't inflate more than 5-10% past the rated amount.