Tuesday, August 9, 2011

More on seat height...and boobs.

Basically, I'm a dumbass.

My knee hurt because I carelessly put a new saddle on a bike with no regard to setback. All better now.

I have still been poking around for bike fit info. Not changing anything..just learning. Here is some more seat height wisdom from Steve Hogg, a pretty smart guy when it comes to bike fit. No laser and smoke BS. Anatomy and kinesiology at work:

How to set seat height accurately if you are a bike fitter:
Focus on the velocity of extension of the rear of the knee under significant load.  That velocity should be a constant.  If you see even the tiniest flicker of acceleration at the rear of the knee before the bottom of the pedal stroke, then the rider is losing control of the motion and is too high; at least on that side.  If in doubt, increase the load a touch.  Always check the other side under similar load and if there is a difference in fluency between sides, have a look at the pelvis from the rear for your clues as to why.  What is significant load?
Significant load is enough resistance to have the rider forcing the gear a bit at 80 – 85 rpm but not so much as to sacrifice technique.  This kind of load is similar to riding a hill hard while seated, in one gear harder than is comfortable. Under this load, better than 99% of riders will drop their heels more, and extend their legs more than they will under less load or in flat riding where momentum plays more of a part. It is this kind of load that determines seat height.

How to set your own seat height:
Find a hill that takes at least 3 minutes to ride up. Warm up thoroughly and then ride up that hill under significant load (see above for definition of significant load).  Do you feel like you are riding a step machine or do you feel fluent through the bottom of the stroke on both legs?

If you feel like you are on a step machine or feel a bit powerless, drop your seat 3mm and repeat the hill.

If you feel equally fluent through the bottom of the pedal stroke on each side, raise your seat 3mm and repeat.

For those who have to drop their seat, repeat the hill and drop the seat 3mm per time until you feel fluent through the stroke while forcing the gear.

For those who have to raise their seat, repeat the hill and raise the seat until you feel like you are a touch less fluent on one side than the other.  This is an early warning sign that you have entered challenge territory.  (For more info about challenges.)

Now drop your seat 6mm.  Why not just drop the seat to the last 3mm increment?  Because not every day is the best day of your life.

For the patient ones still looking for the boobs: Sorry. Google Liz Hatch or something.

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