# Seat height...32 inseam with 31.5 inch seat height? Am I a freak of nature?



## Stu_the_weak (Jan 25, 2010)

My inseam is 32 inches. Just measured my seat height and it's 31.5 inches.

If you go by those wacky .883 or .885 ratios I should be using a seat height of 28.36 inches.

Am i completely off my rocker? Who came up with those numbers? I swear I have no less than a 30 degree angle in my knees at the bottom of my crank. How is that even possible?

Anyone have a clue?

Stu


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## pdh777 (Oct 7, 2005)

Your pant inseam is not your bike inseam - go to wrenchscience.com to see how they measure inseam. If you do this your numbers should be more in line.

The crank arm should be in line with your seat tube when measuring for the angle.

Did you measure twice?


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## SystemShock (Jun 14, 2008)

pdh777 said:


> Your pant inseam is not your bike inseam - go to wrenchscience.com to see how they measure inseam. If you do this your numbers should be more in line.


Yup. For example, I wear a 30-inch inseam in Levis, but my 'cycling inseam' is 32.1 inches. 

Pretty big diff.
.


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## waldo425 (Sep 22, 2008)

Nope you're normal --- sorry


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## boon (Dec 14, 2005)

or you must be pedaling with extreme toe down.


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## wim (Feb 28, 2005)

Stu_the_weak said:


> Who came up with those numbers?


Cyrille Guimard, who coached, among others, Greg Lemond (a relatively successful professional bicycle rider in the late 1900s). Of course, those .883 or .885 numbers working out fine for Mr. Lemond doesn't mean they'll do the same for you.


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## merlinluvr (Feb 6, 2010)

Stu_the_weak said:


> My inseam is 32 inches. Just measured my seat height and it's 31.5 inches.
> 
> If you go by those wacky .883 or .885 ratios I should be using a seat height of 28.36 inches.
> 
> ...


A lot of things can effect that in my opinion. I have custom midfoot cleats which ended up lowering my saddle height by 2.5cm alone from the ball of foot over spindle gig we hear so much about. Mine are not quite midfoot, but much further back than any normal pedal system will come stock in rearward adjustment. I'm 6'1", 35" inseam and have a saddle height of 755mm from center of bb through the seat tube to top dead center of saddle. The 'custom' fit I had done had my saddle at 792mm with an extreme toe down pedal position and the ball of my foot nearly 1cm behind the spindle. I developed a horrible Achlles injury which kept me off the bike for nearly 6 months after. Personally, I don't feel there is any hard and fast rule which applies to all b/c there are so many variables from rider to rider.


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## TWB8s (Sep 18, 2003)

I'm 5' 11" with a 32" inseam for jeans. I've been fitted twice (12 years apart) and my saddle height hasn't changed... 782mm from BB center. What your foot does through the pedal rotation factors into the measurement. Fixed or flexing ankle, flat or angled foot... get the idea?


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## George M (Sep 25, 2008)

merlinluvr said:


> A lot of things can effect that in my opinion. I have custom midfoot cleats which ended up lowering my saddle height by 2.5cm alone from the ball of foot over spindle gig we hear so much about. Mine are not quite midfoot, but much further back than any normal pedal system will come stock in rearward adjustment. I'm 6'1", 35" inseam and have a saddle height of 755mm from center of bb through the seat tube to top dead center of saddle. The 'custom' fit I had done had my saddle at 792mm with an extreme toe down pedal position and the ball of my foot nearly 1cm behind the spindle. I developed a horrible Achlles injury which kept me off the bike for nearly 6 months after. Personally, I don't feel there is any hard and fast rule which applies to all b/c there are so many variables from rider to rider.



I have the same measurements and I have mine set at 78.7. Sometimes I wonder if I'm too low. That .883 is pretty close to where I'm at.


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## Dinosaur (Jan 29, 2004)

Mine is dead on with the .883 ratio. However I have my saddle slammed way back, which in essence raises your saddle. I ended up there by experimenting. Never knew until I took a measurement one day..


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## Dereck (Jan 31, 2005)

I might make a 30" inseam, by the boringly old fashioned way of measuring it, and ride with a 29-3/8" seat height (crank axle centre to saddle top, up the seat tube centreline). Also found I prefer 172.5mm cranks - tried them two years back after riding 170mm since re-starting cycling some seven years. Shimano road pedals keep me connected.

If I followed that formula, I'd be miserable. Tried it around the block once. Not fun...

Essential is that you 'listen' to what your body is telling you when you ride. If you change some measurement, have good reason and change only one.

And keep a list of your bike's vital statistics so if you ever replace/change/break/wear out something, you restore your beloved to her rightful shape.

Regards

Dereck


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## merlinluvr (Feb 6, 2010)

George M said:


> I have the same measurements and I have mine set at 78.7. Sometimes I wonder if I'm too low. That .883 is pretty close to where I'm at.


As long as it feels good that is all that matters


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## merlinluvr (Feb 6, 2010)

TWB8s said:


> I'm 5' 11" with a 32" inseam for jeans. I've been fitted twice (12 years apart) and my saddle height hasn't changed... 782mm from BB center. What your foot does through the pedal rotation factors into the measurement. Fixed or flexing ankle, flat or angled foot... get the idea?


That is a great point that blows over a lot of cyclists heads when battling a fit. I'm a 'fixed' type of pedal stroke guy so my saddle is significantly lower. Keeping dorsiflexion throughout the stroke makes me quite a bit more powerful as verified by using my pals PT wheel. Have no idea why, but it works for me. I have actually read where dorsiflexion costs a bit more in energy(Cannon I believe was his name), but it works for me. I don't get dead leg any more with this type of stroke and the only reason I fought it for years was b/c I listened to "you gotta have your saddle higher and you MUST get the ball your foot farther back!" 

Whatever works.....roll with it


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## George M (Sep 25, 2008)

merlinluvr said:


> As long as it feels good that is all that matters


I'm always playing with it and I had it at 79cm and it didn't feel bad, but I'm getting chafing and I thought I would drop it.I dropped it to where I have about a 15 degree bend. It's hard to tell while riding though. When I got fitted at 2 bike shops they had me at 31" or 78.8. If this weather breaks a little I'm going to try the 78.8 and see what happens with the chafing. I had it at that measurement before, but it was on my Specialized with a Brook Swift and didn't have any problems at all.
If I still get the chafing, I'll try your measurement and see what happens. I like the Fizik Aliante saddle, but with the chafing going on I'll have to change.


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## jitahs (Mar 7, 2006)

My pbh is 32"; the .883 ratio gives me a 72.0cm seat height. Exactly where my really good fitter put me.


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## merlinluvr (Feb 6, 2010)

George M said:


> I'm always playing with it and I had it at 79cm and it didn't feel bad, but I'm getting chafing and I thought I would drop it.I dropped it to where I have about a 15 degree bend. It's hard to tell while riding though. When I got fitted at 2 bike shops they had me at 31" or 78.8. If this weather breaks a little I'm going to try the 78.8 and see what happens with the chafing. I had it at that measurement before, but it was on my Specialized with a Brook Swift and didn't have any problems at all.
> If I still get the chafing, I'll try your measurement and see what happens. I like the Fizik Aliante saddle, but with the chafing going on I'll have to change.


Oh man please don't try my numbers based on my silly rec! I think it would be a disaster if you run a 'normal' cleat position b/c my cleat center is probably 2+cm further back than yours at least.. That alone dropped me over 2cm in saddle height and would hate for you to get an injury listening to my dumb ass. I had to go the midfoot cleat route due to injuries. In turn I'm a better cyclist with them, but it's not for everyone.


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## George M (Sep 25, 2008)

Hey merlin, I just looked at your post on wacky looking setup and I know what our difference is. You have your saddle setback at 6cm and I have mine at 8.5cm. So I think that would make up the difference.


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## merlinluvr (Feb 6, 2010)

George M said:


> Hey merlin, I just looked at your post on wacky looking setup and I know what our difference is. You have your saddle setback at 6cm and I have mine at 8.5cm. So I think that would make up the difference.


You know what? I wish there was a way or if there is that I knew of it to actually find out what your individual setback is while riding. Since I sit sooo far back on my saddle I could conceivably have more effective useable setback than you at 8.5 depending on where you sit. No? I do have a flat saddle so I can move all over, but I ride about 2* nose up which makes the back of my saddle feel like a Lazy Boy. I tell ya even comparing one identical set of inseams, torso, foot sizes....you could get one completely different fit. Bike fitting is a never ending saga!


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## George M (Sep 25, 2008)

I just thought about that. If I have my saddle back farther than you I should actually have it lower. Your right about the difference in saddles though. The saddle I'm playing with now is a Fizik Aliante and I set it as far as the gage leaves me. While riding I have about 1cm showing in the back. From the nose to the handlebars is 22". From the back of the saddle to the handlebars I got 32.5 and the rails on the saddle are 3" long.


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## SystemShock (Jun 14, 2008)

merlinluvr said:


> You know what? I wish there was a way or if there is that I knew of it to actually find out what your individual setback is while riding.


There kinda is... if you read the Hinault/Genzling book. It involves measuring the proportion of your thigh and shin lengths, and comparing it to a table.

Worked for me. I have unusually long thighs, and it got me pretty close to where I need to be.
.


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## SystemShock (Jun 14, 2008)

jitahs said:


> My pbh is 32"; the .883 ratio gives me a 72.0cm seat height. Exactly where my really good fitter put me.


Yup. My inseam is 81.6cm, and my saddle height is 72.3cm, which works out to .886

So the .883 (LeMond) was only off by 2.5mm, and the .885 (Hinault) was off by 1mm. Damn close to perfect pour moi.

But I wonder how many ppl are still confusing 'pants inseam' with 'cycling inseam'? :idea: 

hint: Your pants don't reach all the way to the floor, or at least, they shouldn't. 
Nor is there any upward pressure while wearing pants (like there is while sitting in the saddle)... or again, there shouldn't be. 
.


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## George M (Sep 25, 2008)

SystemShock said:


> There kinda is... if you read the Hinault/Genzling book. It involves measuring the proportion of your thigh and shin lengths, and comparing it to a table.
> 
> Worked for me. I have unusually long thighs, and it got me pretty close to where I need to be.
> .



I forgot I have the book:mad2: I guess it doesn't get any better the older I get


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## capt_phun (Jun 14, 2004)

George M said:


> I just thought about that. If I have my saddle back farther than you I should actually have it lower. Your right about the difference in saddles though. The saddle I'm playing with now is a Fizik Aliante and I set it as far as the gage leaves me. While riding I have about 1cm showing in the back. From the nose to the handlebars is 22". From the back of the saddle to the handlebars I got 32.5 and the rails on the saddle are 3" long.


Not trying to be a douchebonnet, but it helps if you talking in metric (cm), as that is what cycling is more based around. Inches is not used as much cause really who sets their seat height to 29 & 3/32". Its easier to express in like 71.8cm.
get a ruler with CM.
Ok rant off.


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## George M (Sep 25, 2008)

capt_phun said:


> Not trying to be a douchebonnet, but it helps if you talking in metric (cm), as that is what cycling is more based around. Inches is not used as much cause really who sets their seat height to 29 & 3/32". Its easier to express in like 71.8cm.
> get a ruler with CM.
> Ok rant off.



I usually use metric as well, but the op was using inch's and I didn't know if he had a metric ruler or tape. Thanks for the input.:thumbsup:


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