ArmChairRider

GLIDING !!!

You know you want to do it.
You know you will have to do it.

Let me explain. After you have done all the math, consulting, inseam measurements, top tube straddling...
there still remains one thing, you.
Take an occasion while you are riding to glide. Gliding can give you a rest and it helps avoid a pounding from the seat when riding over rough spots in the road. Glide by standing on the pedal with one leg naturally straight. While hovering over your seat the pedal will be a little forward, while standing up off the seat vertically the pedal will be all the way down.

Keep doing it until it becomes natural.

If you feel like you have to climb back up in your seat then your seat is too high. If you feel like you are expending extra effort to stand on your pedals and hover over your seat and glide then your seat is too low. You should be able to effortlessly go from a seated position to a standing position while gliding.

Let the arc of the pedal carry you there.

In fact it should be so effortless that you'll catch yourself standing up when you really weren't thinking about standing up.

oldbobcat

I like the simplicity of it. Takes into account leg length, preferred extended knee angle, foot angle, foot size, crank arm length, pedal stack height, shoe and sock stack height, chamois thickness, etc., etc., without touching a single measuring device.

I used to ride with a guy who actually had to hitch himself up on tiptoes to get back onto the saddle. His bike is too big, too.

trailangel

Huh?
We call that coasting.

ArmChairRider

~But I don't wanna be a coaster.~

ArmChairRider

I know, I was one of those guys. haa haa. I got the math written down in a Schwinn manual somewhere around here.
I'm like "This is suppose to work?"

deapee

As a complete numbers guy myself, I know every formula there is...and I use the heel to pedal method. I've never failed to get a bike within half a CM of the .883 formula using the heel method. For me, .883 plus half to 1 CM is where I like to be. Half CM being road, 1CM being more upright.

ArmChairRider

Yup, I was using the .833 formula as well.

Road Fan

A lot of times in engineering work, we'll be yammering along about numbers, equations, criteria, requirements, tolerances, critical voltages or angles or lengths et cetera, when someone has a flash of creative insight and says "We just need to see what WORKS! why don't we just blah blah blah and then we'll know!"

I think this is one of those moments!

Yes, do the numbers, et cetera. but then try this gliding thing and see if the positioning works!

deapee

Yeah...we do tend to over-complicate things a lot -- As a senior engineer myself, I sometimes have to step back and come up with a solution so simple that I make people question whether a 6 year old could have done what they couldn't have.

TKJava

For a seat height adjustment I'll go with the knee almost locked out with the heel on pedal and then move back to the ball of the foot to see if the knee has the "correct" angle. I like to then ride 2 or 3 times for about an hour or more for each ride. Afterward note do I have any stretching pain behind my knee, did my thighs feel stressed at all etc. If nothing then I move the seat either up or down and see how I feel. Sometimes its hard for me to tell (within reason) what's comfortable until I ride with a particular adjustment then make a change. The change is typically immediately noticeable either better or worse. So as an engineer I use "the numbers" to start with then go with a feel in the end.