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Discussion Starter · #1 ·
My inseam is 80.33 cm near as I can figure. What in your opinion should my seat height be?

I'm thinking I'm riding too high. I've been diddling with this for years And I thought taller was better but now I'm not so sure.

Whereabouts would you put the seat for me?

Thanks
 

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Slow-poke
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Why not lower your seat alittle and see if you feel better. Most people would tell you to try one of the myriad of formulas, and then adjust from there. Change the seat hight in fractions of a centimeter to get used to it. Drastic change could be bad.
 

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Discussion Starter · #3 ·
Thanks Paul but the common sense stuff I already have figured out. I've been up and down, comfort isn't really the issue.

What I want are specific height recommendations based on physiological efficiency. I've read that seat height can affect your power output dramatically so I want to hear what other people do.
 

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hi, I'm Larry
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Wasn't this just covered in the Lemond

formula thread. Something like .881 X your real inseam (not pants inseam).

Me, I like a high forward position and like to spin. So I'm about a half inch more than the formula. I used trial and error to arrive at this position. First, over time moved my seat forward as far is it will go (I would now like to move forward another couple of Cm). Then raised my seat up over time until it was clear my hips were rocking slightly when riding and then dropped it down until I had a nice smooth flow at high cadence. Foot position makes a big difference in seat height. I ride with the toe slightly down with the ankle locked. I find myself ankling when I am not focusing (old habits are hard to break and ankling is comfortable to me having done it for decades)
 

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asking too much...

If you've been up and down and not experienced a significant difference in power output, this indicates that what other people say about "dramatic increases in power" is probably wrong.

Most changes are really a tradeoff on how the power is developed. Since power = torque x cadence, a power increase would have to be derived with an increase in torque without sacrificing cadence or vice-versa.

What you should evaluate when applying maximum power is the part of our body that fails first. If your legs burn out first you may be trying to use too much torque. If your lungs are the first to go, then you may be spinning too much. Either of these situations may merely be the result of selecting the wrong gear for the situation. I often ride 1-2 cogs lower, at a higher cadence than a gear-masher (at the same speed). What works for the gear-masher doesn't work for me.

My personal experience is that a saddle set too high will reduce cadence and cause the leg to apply force at an extreme angle where it is not efficient, at the bottom of the stroke. A saddle set too low will increase cadence, but may use the leg at an inefficient angle at the top of the stroke. A happy medium is the answer. My rough guide on saddle height is to be sure that you can drop your heel 3-4cm below horizontal at the bottom of the stroke, to insure a significant (10-15 degree) bend in the leg at the bottom of the stroke during normal pedaling.

Saddle fore-aft position definitely seems to affect the ability to apply torque to the pedals from my experience. As the saddle is moved further back more torque can be applied, but if the position reduces your cadence, nothing may be gained. Moving the saddle forward has the opposite effect. Anytime the saddle is moved forward or back, it should be moved up or down (respectively) by 1/3 the amount of the fore-aft movement to maintain the same maximum leg extension. If this is not done, then you are changing both position and the amount of leg extension, which can lead to confusing results.
 

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Sintesi said:
Thanks Paul but the common sense stuff I already have figured out. I've been up and down, comfort isn't really the issue.

What I want are specific height recommendations based on physiological efficiency. I've read that seat height can affect your power output dramatically so I want to hear what other people do.
if you wanna play with numbers check analyticcycling.com pedaling model. Basically you wanna keep your leg as close to straight w/o damaging knee. 0.5-1.5cm won't make noticable difference; you need to make adjustments for shoe, stack height. You can put saddle higher for TT. Keeping saddle slightly lower gives more comfort, which is more improtant on longer rides.
 

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no formula

Sintesi said:
My inseam is 80.33 cm near as I can figure. What in your opinion should my seat height be?

I'm thinking I'm riding too high. I've been diddling with this for years And I thought taller was better but now I'm not so sure.

Whereabouts would you put the seat for me?

Thanks
No formula could possibly work for everyone, which means it likely won't work for you.

What I have always done, and this has always worked, is to mount the bike on a trainer and sit normally on the bike, bike shoes on and then clip in both feet. Set seat height so that at BDC, with feet level, the leg is slightly bent.

Typically you know the seat is too high if the rear of your knees hurt, your hips rock on the saddle, and/or you get a lot of chafing from rocking. You can get excess perineum pressure, too.

Too low and you'll get pain on the front of your knees and feel underpowered and cramped on the bike.

Once you get it set, measure with a tape from the top of your saddle to center of your crank bolt, or some other reference, then keep it the same on all your bikes or after you move or replace something. My measurement is 28 5/8 inches. If you use shorter cranks on some bikes, you might need to account for that, though.

Doug
 

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For me, fore/aft effects efficiency, height effects comfort.

If I get the seat too high, my lower back hurts first and then my achilles tendons. Too low and my knees stick out to the sides and my hips and butt feel creaky. There doesn't seem to be much difference in efficiency or speed at the same level of effort.

As others have said, there is no formula that works for everybody. .883 of inseam, heal on top of the pedal with your leg straight, and formulas involving joint angles and fancy devices to measure them all get close.

I agree that fore/aft placement directly effects how you pedal. Moving the seat forward helps spinners spin faster. Moving it backwards helps mashers mash harder. Even then there's no formula to tell everybody where to put their seat.

It seems, at times, that it makes little enough difference that a person who's convinced by a believably presented formula that his/her seat is in exactly the right place is more efficient than somebody in doubt.
 

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Discussion Starter · #9 ·
Just searched for the thread. I figured the new forum wouldn't have this topic yet. Good stuff in that thread and here.

Thanks a bunch.

thanks everyone for your advice.

Looks like after years of adjustment here and there I want to start over and go back to the drawing board. thanks again.
 

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Two numbers

Center of BB to top of saddle = 0.881-0.883 of inseam.

Top of pedal to top of saddle = 108-110% of inseam.

You'll find these give similar answers, and of course are starting points depending on your own physiology and flexibility. Getting very far from these numbers is likely not a good idea.
 

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I'm at 0.90

I set my saddle where it felt comfortable. Over a period of time I gradually raised it. Checking the height, center of BB to top of saddle I'm at 0.90

My inseam is 35" (88.9cm)

88.9 X 0.90=80.01 cm (31.5")
0.883 x 88.9= 78.5 cm (30.9")

Difference between two settings is 1.5 cm.

It probably makes a difference where you set your saddle, mine is in the middle of it's rails with a 73 sta.


Another method I've read about is knee bend. Some say 25%, the American Academy Of Orthopedic Surgeons recommends 15% for patients for knee problems (chondra malacia). A lower setting generates more power but puts great pressure on the knee. They say the higher the better, without rocking your hips is where you want to set your saddle. Flexibility makes it able for you to ride with a higher saddle setting, but I'm pretty un-flexible for a 61 year old guy.

I don't know how all this stuff works, I just set by feel and when I got everything where it felt right I took measurements so I know where I'm at it and when it comes time to set up a new bike.

I got most of this information out of "Training For Cycling" By Davis Phinney and Connie Carpenter. Phinney's setting was at 0.91, Connies at 0.90, LeMonds at 0.883, and who knows where Merckx set his. That's a clue that's it's one for all....
 
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