Originally Posted by
Jimi77
Doesn't work for me. 34" * .883 = ~30". Saddle height is currently at 31", which is too low.
No, it does work for you, you just disagree and I would say quite likely your saddle is too high, what tells you that 31 is your magic number, a divining rod? It is currently in vogue to ride with the saddle jacked way up and the hips rocking. I see it all the time. Actually, I use 1.09 X PBH.
In any case, the resulting calculated height is not exact, it is a starting point to fine tune up or down from considering your cleat/pedal stack, crank length and other factors. It gets you very close and for many people it is spot on.
Some years back it was the fashion to ride frames that were too large, now it is the fashion to ride frames that are too small with the seat pulled up so far the rider has to rock and over extend. Unfortunately for fashion, the physical parameters of the human body are not nearly so variable as many think.
Originally Posted by
fietsbob
Much simpler...
Leg straight, heel of your foot, just reaches the pedal.
You normally ride with the ball of your foot over the spindle of the pedal,
so at the bottom of the stroke, there is still a bend in your knee..
simple
Well, that works, but is that with your shoes on? Some riding shoes have a heel, some don't? is it in stocking feet? I can still have a bend in my knee easily over about a two inch range in my saddle height, especially if I rock my hips a tiny bit I can go even higher.
"An extensive study on bicycle design was done at Loughborough University (Pronounced Luff-boro.) in England in the mid 1970s. Part of their report stated that saddle height, measured from the pedal surface to the top of the saddle, was equal to 109% of a rider’s inside leg measurement.
The way they arrived at this 109% was by measuring the inside leg of a large number cyclists, and at the same time measured the height of their saddles. 109% was the average; in reality, most of the cyclists measured would have been above or below this percentage. This is the nature of averages.
The 109% is a place to start; the saddle height for most people is going to be slightly up or down from this. I like the idea of a percentage because the longer a rider’s legs, their saddle is going proportionately higher. This means a greater distance from the saddle to the handlebars, (Drop.) which is what the larger rider needs."
Notice the use of the word average above, some were higher, some lower. But if you are far away from the calculation then something is odd.