Bike Fit
08-30-19, 09:17 PM
#1
Senior Member
Thread Starter
Bike Fit
Was suggested that I post this here, too. Sorry if I'm doing this wrong.
So I took some measurements and put them into the Competitive Cyclist Fit Calculator. Either I did something entirely wrong (checked all measurements multiple times, usually within 0.125 inches), or I am just not standard. Anyone look at this and think something is grossly wrong?
Also measured wing span at 72.625 inches vs 74 inch height, so -1.375 inch index.
https://www.bikeforums.net/road-cycling/1182536-bike-fit.html
So I took some measurements and put them into the Competitive Cyclist Fit Calculator. Either I did something entirely wrong (checked all measurements multiple times, usually within 0.125 inches), or I am just not standard. Anyone look at this and think something is grossly wrong?
Also measured wing span at 72.625 inches vs 74 inch height, so -1.375 inch index.
https://www.bikeforums.net/road-cycling/1182536-bike-fit.html
09-01-19, 08:07 AM
#2
Senior Member
Join Date: Sep 2009
Location: USA
Posts: 2,067
Bikes: 84 Pinarello Trevisio, 86 Guerciotti SLX, 96 Specialized Stumpjumper, 2010 Surly Cross Check, 88 Centurion Prestige, 73 Raleigh Sports, GT Force, Bridgestone MB4
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 278 Post(s)
Liked 71 Times
in
56 Posts
How tall are you and what is your true pubic bone height?
PBH is measured in bare feet, your back against the wall, stand up straight and square. Have a wife, gf, buddy, whatever take a one inch hard bound book and shove it up into your crotch, square to the wall until it is hard against the bone and make a mark on the wall at the top of the book. That is your PBH or cycling inseam.
Next, multiply that number by by .883 and set that as saddle crown to BB center (measured along the ST) and that is your starting point saddle height. Then multiply PBH by .65 and that is your ideal seat tube (ST) length measured C/C (for a level top tube). It is also, just so happens to be a good top tube (TT) length starting point.
Me, I like the Lemond fit. The above is a starting point and works really good for the "Leonardo man" body type.
Then you have to adjust to account for differences in the physical built, long arms, long torso, short arms, long torso etc. It is not an exact science. And people have different thoughts on fit. Let me add, the sloped TT bicycle frame has been a godsend for some folks though asthtically I dislike them. For example, one of the most challenging body types to fit is the person with a Michael Phelps body! Looooong arms, loooong torso and short legs. We have to make a series of compromises with off the shelf frames and in the past such folks had to give up some stand over or ride a bike a bit too small and compensate with a long stem and so on. Sloped top tube bikes certainly help such body types to get a much better fit.
Me, long arms, long legs, slightly shorter torso. I am easy to fit.
PBH is measured in bare feet, your back against the wall, stand up straight and square. Have a wife, gf, buddy, whatever take a one inch hard bound book and shove it up into your crotch, square to the wall until it is hard against the bone and make a mark on the wall at the top of the book. That is your PBH or cycling inseam.
Next, multiply that number by by .883 and set that as saddle crown to BB center (measured along the ST) and that is your starting point saddle height. Then multiply PBH by .65 and that is your ideal seat tube (ST) length measured C/C (for a level top tube). It is also, just so happens to be a good top tube (TT) length starting point.
Me, I like the Lemond fit. The above is a starting point and works really good for the "Leonardo man" body type.
Then you have to adjust to account for differences in the physical built, long arms, long torso, short arms, long torso etc. It is not an exact science. And people have different thoughts on fit. Let me add, the sloped TT bicycle frame has been a godsend for some folks though asthtically I dislike them. For example, one of the most challenging body types to fit is the person with a Michael Phelps body! Looooong arms, loooong torso and short legs. We have to make a series of compromises with off the shelf frames and in the past such folks had to give up some stand over or ride a bike a bit too small and compensate with a long stem and so on. Sloped top tube bikes certainly help such body types to get a much better fit.
Me, long arms, long legs, slightly shorter torso. I am easy to fit.
Last edited by Loose Chain; 09-01-19 at 08:25 AM.
09-01-19, 09:59 AM
#3
Member
Rule of Thumb for Top Tube Height
Hey All,
My personal height preference for straddling my a bike's top tube is to have 1 inch (25mm) to 1 1/2 inches (37mm) from my perineum to the top edge of the tube.
This rule of thumb is a comfortable height for a road bike (I ride a 1984 Motobecane Mirage Sport.)
Other bike configurations, such as BMX, Mountain, etc,. may require more "spacing."
Additionally, personal preferences always trump specs, guidelines and rules of thumbs. . . so, it becomes a "whatever makes you feel comfortable" issue.
Ride hard, ride safe.
J.
My personal height preference for straddling my a bike's top tube is to have 1 inch (25mm) to 1 1/2 inches (37mm) from my perineum to the top edge of the tube.
This rule of thumb is a comfortable height for a road bike (I ride a 1984 Motobecane Mirage Sport.)
Other bike configurations, such as BMX, Mountain, etc,. may require more "spacing."
Additionally, personal preferences always trump specs, guidelines and rules of thumbs. . . so, it becomes a "whatever makes you feel comfortable" issue.
Ride hard, ride safe.
J.
09-01-19, 02:50 PM
#4
just another gosling
Join Date: Feb 2007
Location: Everett, WA
Posts: 19,528
Bikes: CoMo Speedster 2003, Trek 5200, CAAD 9, Fred 2004
Mentioned: 115 Post(s)
Tagged: 0 Thread(s)
Quoted: 3886 Post(s)
Liked 1,938 Times
in
1,383 Posts
So you have a short torso. What's the issue? Run a short stem. A very wide range of reach has been found to be comfortable. I had a fitter shorten my reach by 3 cm recently and can't say I notice any difference in comfort at all. Many pros ride small frames with their elbows scrunched back behind their knees, like this guy:
And then there are riders who use a lot of reach, like this woman:
Go to your LBS and sit on some bikes, see how they feel. Numbers are nice but . . .
Personally, I'm in the "lots of reach" camp. Opens the chest, flattens the back, lightens the hands, feels more aero, etc. Learn to love reach.
And then there are riders who use a lot of reach, like this woman:
Go to your LBS and sit on some bikes, see how they feel. Numbers are nice but . . .
Personally, I'm in the "lots of reach" camp. Opens the chest, flattens the back, lightens the hands, feels more aero, etc. Learn to love reach.
__________________
Results matter
Results matter
