Go Back  Bike Forums > Bike Forums > Road Cycling
Reload this Page >

Average Male Inseam to Height Ratio?

Notices
Road Cycling ďIt is by riding a bicycle that you learn the contours of a country best, since you have to sweat up the hills and coast down them. Thus you remember them as they actually are, while in a motor car only a high hill impresses you, and you have no such accurate remembrance of country you have driven through as you gain by riding a bicycle.Ē -- Ernest Hemingway

Average Male Inseam to Height Ratio?

Old 11-06-21, 08:23 AM
  #51  
Sy Reene
Advocatus Diaboli
 
Sy Reene's Avatar
 
Join Date: Feb 2015
Location: Wherever I am
Posts: 7,764

Bikes: Merlin Cyrene, Nashbar steel CX

Mentioned: 12 Post(s)
Tagged: 1 Thread(s)
Quoted: 4177 Post(s)
Liked 1,171 Times in 768 Posts
Seems pointless, unless you also layer in metrics such as average arm length, average neck and head height (or alternatively average torso length) etc.
Sy Reene is offline  
Old 11-09-21, 05:43 PM
  #52  
ZHVelo
Senior Member
 
Join Date: Apr 2020
Location: Zurich, Switzerland
Posts: 693
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 409 Post(s)
Liked 177 Times in 130 Posts
Originally Posted by biker7 View Post
Don't know if you have a background in statistics or not. Bottom line is inseam length (independent of height) still dominates for the vast bell curve of cyclists out there. There is a correlation however. Dave Moulton's chart is derived by thousands of fittings and he is a pre-eminent expert on the subject. So is Sheldon Brown. Both subscribe to the 2/3 X's cycling inseam for frame size. I do too. Statistically most (not all) derive their height in their legs. Tall people many times have pedestrian length torsos. This applies to Sheldon Brown and myself and countless others. As a result, bicycles are designed to grow vertically almost 2:1 versus horizontally in frame size. This is not happenstance but based statistically on a normal distribution of height to inseam ratio. The reason that seat tube length or now virtual seat tube length with the advent of sloped top tube geometry bikes predominates is because virtual or actual seat post length dictates head tube length. In the grand scheme it is the ratio of seat post to head tube length that matter for saddle to handlebar drop. The other prevailing factor is top tube length and again, top tube does not increase nearly as must as seat post and head tube length between frame sizes which agrees with the statistical norm that torso size does not change nearly as much as inseam for different size people.
HTH,
George
So say 87 inseam * 2/3 = 58 so a 58 frame?
ZHVelo is offline  
Old 11-10-21, 05:09 PM
  #53  
PeteHski
Senior Member
 
PeteHski's Avatar
 
Join Date: May 2021
Posts: 3,262
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 1540 Post(s)
Liked 1,648 Times in 1,050 Posts
Originally Posted by THEKXIL View Post
177cm tall
96.5cm inseam
55%
That is one hell of an inseam relative to height!
PeteHski is offline  
Old 11-10-21, 09:07 PM
  #54  
Kabuto
Senior Member
 
Kabuto's Avatar
 
Join Date: Jul 2017
Location: Far East
Posts: 244
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 156 Post(s)
Liked 63 Times in 41 Posts
"Men will typically have an inseam 46-47% of their height and although it may not sound like a big difference, less than 45% or more than 48% is noticeable short or long legged respectively. Contrary to some popular opinion, women do not have longer inseams as the ratio is very similar. Women's legs appear longer as their waists are higher."

Copied from the website below.

https://bikedynamics.co.uk/bikesizingbd.htm
Kabuto is offline  
Old 11-11-21, 03:27 PM
  #55  
Rdmonster69
Shawn of the Dead
 
Join Date: Apr 2021
Posts: 508
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 247 Post(s)
Liked 406 Times in 194 Posts
Originally Posted by PeteHski View Post
That is one hell of an inseam relative to height!
Totally !!

I'm 185 Cm (73 and a smidge inches) with a 94 cm (37 inch) cycling inseam if I have my math correct.

Over 50% leg !!

Zombie thread is fun lol.
Rdmonster69 is offline  
Old 11-11-21, 03:36 PM
  #56  
Cyclist0108
Occam's Rotor
 
Join Date: Jul 2013
Posts: 7,248
Mentioned: 61 Post(s)
Tagged: 0 Thread(s)
Quoted: 2366 Post(s)
Liked 2,322 Times in 1,157 Posts
Does anyone know how much this ratio has changed since 2007?

My ratio is 0.43.
Cyclist0108 is offline  
Old 11-11-21, 04:40 PM
  #57  
Sy Reene
Advocatus Diaboli
 
Sy Reene's Avatar
 
Join Date: Feb 2015
Location: Wherever I am
Posts: 7,764

Bikes: Merlin Cyrene, Nashbar steel CX

Mentioned: 12 Post(s)
Tagged: 1 Thread(s)
Quoted: 4177 Post(s)
Liked 1,171 Times in 768 Posts
Well, obviously in the far past the ratios were much lower, but not sure 2007 was back far enough

Sy Reene is offline  
Old 11-11-21, 05:50 PM
  #58  
ofajen
Cheerfully low end
 
ofajen's Avatar
 
Join Date: Jun 2020
Posts: 1,408
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 436 Post(s)
Liked 678 Times in 445 Posts
Originally Posted by Kabuto View Post
"Men will typically have an inseam 46-47% of their height and although it may not sound like a big difference, less than 45% or more than 48% is noticeable short or long legged respectively. Contrary to some popular opinion, women do not have longer inseams as the ratio is very similar. Women's legs appear longer as their waists are higher."

Copied from the website below.

https://bikedynamics.co.uk/bikesizingbd.htm
Looks like my head unit estimate (3.5/7.5 = 46.7%) was pretty much on the mark. And itís true that a few percent is noticeable. Iím at about 49% and definitely tending to the longer leg side of the distribution.

Otto
ofajen is online now  
Old 11-11-21, 06:05 PM
  #59  
Kimmo 
bike whisperer
 
Kimmo's Avatar
 
Join Date: Dec 2009
Location: Melbourne, Oz
Posts: 9,455

Bikes: https://weightweenies.starbike.com/forum/viewtopic.php?f=10&t=152015&p=1404231

Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 1471 Post(s)
Liked 683 Times in 483 Posts
[QUOTE=Blopslee;4073286]
Originally Posted by MIN
Interesting insight from that link:

The way I determine frame size is to start by saying this equals two-thirds of the riderís inseam.

I think things were thought to be a little more clear before sloping top tubes.


I remember tearing my hair out at the wrong turn the industry took with sizing compact frames...

In my view, the obvious way forward was either to switch to effective top tube length, which together with head tube length, is all you really need to know, or to continue with seat tube size, but make it where the effective top tube hits the seatpost, so it continued to mean the same thing. Who gives a stuff about standover clearance anyway?
Kimmo is offline  
Old 11-11-21, 06:26 PM
  #60  
PeteHski
Senior Member
 
PeteHski's Avatar
 
Join Date: May 2021
Posts: 3,262
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 1540 Post(s)
Liked 1,648 Times in 1,050 Posts
Originally Posted by Kabuto View Post
"Men will typically have an inseam 46-47% of their height and although it may not sound like a big difference, less than 45% or more than 48% is noticeable short or long legged respectively. Contrary to some popular opinion, women do not have longer inseams as the ratio is very similar. Women's legs appear longer as their waists are higher."

Copied from the website below.

https://bikedynamics.co.uk/bikesizingbd.htm
I find the website you linked to very interesting. The guy talks a lot of common sense, which is not always the case in this particular field!

It is also very interesting what he says about inseam vs saddle height. He noted that pelvis depth varies widely between individuals and has no correlation to their height. Using his client fit database he came up with a revised formula for predicting saddle height based on both inseam and hip joint height. Full explanation on the link below:-

https://bikedynamics.co.uk/saddleheightformulae.htm
PeteHski is offline  
Old 11-14-21, 10:26 AM
  #61  
philbob57
Senior Member
 
Join Date: Jul 2013
Location: Chicago North Shore
Posts: 1,988

Bikes: frankenbike based on MKM frame

Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 586 Post(s)
Liked 375 Times in 240 Posts
Who gives a stuff about standover clearance anyway?
Ride a bike with too little standover clearance. Then you'll find out.
...effective top tube length, which together with head tube length, is all you really need to know
And the most reasonable conclusion that can be drawn from the discussion of 14 years ago is that many measurements need to be taken into account to achieve good bike fit.
philbob57 is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright © 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.