Road Cycling - Competitive Cyclist Fit Calculator Questions

Ok so just for kicks I filled out the competitive cyclist fit calculator to see what it said.

I'm 5'7" and have a 30 inch inseam. 76.2cm as that's what most measurement tools use.

Here is the rest of the stuff it kicked out for me...

Measurements
-------------------------------------------
Inseam: 29
Trunk: 28.75
Forearm: 13.25
Arm: 24
Thigh: 21.5
Lower Leg: 20.25
Sternal Notch: 55.5
Total Body Height: 67


The Competitive Fit (cm)
-------------------------------------------
Seat tube range c-c: 47.7 - 48.2
Seat tube range c-t: 49.2 - 49.7
Top tube length: 56.1 - 56.5
Stem Length: 11.2 - 11.8
BB-Saddle Position: 67.6 - 69.6
Saddle-Handlebar: 52.9 - 53.5
Saddle Setback: 1.4 - 1.8
Seatpost Type: NON-SETBACK

My question is that my recommended top tube length is approximately 56cm while the seat tube is only 49.2-49.7cm. This is a fairly large difference between the two. I've never found that I've got particularly stumpy legs and or a long torso. I currently ride on a 54cm trek 5500 and find that it fits quite well. I just find it odd that the difference in suggested seat tube lengths is so different.

Any thoughts would be greatly appreciated.

Re-check your measurements, and be sure to do them EXACTLY as described in the instructions. And if that doesn't work, there's always a job in the circus as "Incredible Torso Boy." ;)

I agree, for each measurement take it 3 times and use the average. It could be that you would benefit from a custom frame, and guilt free, unlike most of us "off the rack" poseurs.

vjp

Ok so just for kicks I filled out the competitive cyclist fit calculator to see what it said.

I'm 5'7" and have a 30 inch inseam. 76.2cm as that's what most measurement tools use.

Here is the rest of the stuff it kicked out for me...

Measurements
-------------------------------------------
Inseam: 29
Trunk: 28.75
Forearm: 13.25
Arm: 24
Thigh: 21.5
Lower Leg: 20.25
Sternal Notch: 55.5
Total Body Height: 67


The Competitive Fit (cm)
-------------------------------------------
Seat tube range c-c: 47.7 - 48.2
Seat tube range c-t: 49.2 - 49.7
Top tube length: 56.1 - 56.5
Stem Length: 11.2 - 11.8
BB-Saddle Position: 67.6 - 69.6
Saddle-Handlebar: 52.9 - 53.5
Saddle Setback: 1.4 - 1.8
Seatpost Type: NON-SETBACK

My question is that my recommended top tube length is approximately 56cm while the seat tube is only 49.2-49.7cm. This is a fairly large difference between the two. I've never found that I've got particularly stumpy legs and or a long torso. I currently ride on a 54cm trek 5500 and find that it fits quite well. I just find it odd that the difference in suggested seat tube lengths is so different.

Any thoughts would be greatly appreciated.I had the same issue. And almost he same measurements. We must have made the same mistake. I couldn't figure out the problem.

Something is off somewhere. Did you measure yourself or have someone do it for you? I submit it is not accurate to do it solo.

I did have somebody else do the measurements but I'll re-check it tonight...

And one can only hope for a job in a traveling circus as a certified circus freak. I bet they have a damned good union...

Personally I really like the competitive cyclist calculator and the wrench Science one too. But for them to be of any value you really need super accurate measurments. Get yourself a metric tape measure and make sure the person measuring you is being super, super carefull. Of course once you have these numbers you need to combine them with some basic fit knowledge to make an educated decision on what would be the perfect frame size\geometry for you.

I used that fit calculator and it recommended I get a 50cm frame, my current and comfortable bike is a 56...

Butress the fit calculators with the following link. The guy who put this together is one of the best in the business and works for me and countless others.
BTW you do have a fractionally short inseam for your height. This translates to a slightly longer torso for your height and hence why you may need a bit longer tt but not longer seat post for standover...
http://www.prodigalchild.net/Bicycle6.htm (http://www.prodigalchild.net/Bicycle6.htm)

Are you sure that's your actual inseam? 29 or 30? I doubt a 54 would fit you if that's right.

I dont think the Competitive cyclist calculator is too accurate. It'll give you measurements to suit bikes they sell. I did mine and it told me I need a square 56 with a 120 stem. I currently ride custom 52x59 w 140 stem

Don't use your "pant's inseam" as input, it won't work. To get an accurate inseam length, this is what you've got to do. First, get a friend, spouse or sig-other to help you. This is what you will need:

A good tape measure
A wooden dowel/piece of a broom handle (about 18" in length)
A small bubble level.

I recommend that you do this in running shorts, or the like. Tape the bubble level to one end of the dowel. Standing in your stocking feet, with your back straight and upright as possible, hold the dowel between your legs (front and back) and pull up on the dowel until it is firmly against your "sit bones". The level will help you make sure it is, well...level. Now, have your partner make three, accurate as possible, measurements from the top of the dowel to the floor (do this on a hard floor, like the kitchen, as carpet will throw you off). Average the measurements and use the result as your input and you will get your actual inseam. Do this and then try the bikefit program again, you'll be amazed. :)

That calculator, with very accurate measurements, taken multiple times, precisely depicted the fit that I use on my bikes. The only miss was their recommendation of a straight seatpost which would be very difficult to use with the saddle setback I run.

Try again with your values, especially the inseam.

Said very similar readings for me. Really long top tube along with about the same seat tube length I ride now. I have a long torso and short legs as well. I measured three times. I just figured it was a bug in the program.

Most people not measuring the inseam correctly. I was suprised how accurate and effective the results of competitive cyclist calculator are.

Said very similar readings for me. Really long top tube along with about the same seat tube length I ride now. I have a long torso and short legs as well. I measured three times. I just figured it was a bug in the program.

Funny, I'm long torso and arms with short legs, and it gave me a fit that didn't have a top tube that was close to long enough.

Ok so just for kicks I filled out the competitive cyclist fit calculator to see what it said.

I'm 5'7" and have a 30 inch inseam. 76.2cm as that's what most measurement tools use.

Here is the rest of the stuff it kicked out for me...

Measurements
-------------------------------------------
Inseam: 29
Trunk: 28.75
Forearm: 13.25
Arm: 24
Thigh: 21.5
Lower Leg: 20.25
Sternal Notch: 55.5
Total Body Height: 67


The Competitive Fit (cm)
-------------------------------------------
Seat tube range c-c: 47.7 - 48.2
Seat tube range c-t: 49.2 - 49.7
Top tube length: 56.1 - 56.5
Stem Length: 11.2 - 11.8
BB-Saddle Position: 67.6 - 69.6
Saddle-Handlebar: 52.9 - 53.5
Saddle Setback: 1.4 - 1.8
Seatpost Type: NON-SETBACK

My question is that my recommended top tube length is approximately 56cm while the seat tube is only 49.2-49.7cm. This is a fairly large difference between the two. I've never found that I've got particularly stumpy legs and or a long torso. I currently ride on a 54cm trek 5500 and find that it fits quite well. I just find it odd that the difference in suggested seat tube lengths is so different.

Any thoughts would be greatly appreciated.

Copied the OP's post for refrence but have some questions; The BB to saddle position - is this measured to the top of the saddle? Saddle to HB - Again, to the front of the saddle, or some other place? Saddle setback - ???

http://www.competitivecyclist.com/html/fit/fit_details.html

Updated Results:

So last night I pulled out the super accurate measuring stick and got a better inseam measurement of 30.5...

That said, I guess a 52cm bike would be more along the lines of what I need. I don't think going all the way down to a 50 would work because the top tube would be just way too short.

Who knew, my legs are short and stumpy (or at least as stumpy as a 5'7" 132lb person can be.)

No Dr. Pete freak show though for me...

Measurements
-------------------------------------------
Inseam: 30.5
Trunk: 26
Forearm: 12.5
Arm: 21
Thigh: 21.5
Lower Leg: 20.5
Sternal Notch: 56.5
Total Body Height: 67


The Competitive Fit (cm)
-------------------------------------------
Seat tube range c-c: 50.2 - 50.7
Seat tube range c-t: 51.7 - 52.2
Top tube length: 52.3 - 52.7
Stem Length: 10.2 - 10.8
BB-Saddle Position: 72.1 - 74.1
Saddle-Handlebar: 48.5 - 49.1
Saddle Setback: 2.2 - 2.6
Seatpost Type: NON-SETBACK

Assuming your measurements are correct, you have a relatively short inseam (which is really pubic bone height) for your height, and so it's quite possible that you can use a relatively longer top tube relative to frame height. For example, I'm only 5'3", but my pubic bone height is the same as yours. So you must be making up the extra 4 inches somewhere.

Assuming your measurements are correct, you have a relatively short inseam (which is really pubic bone height) for your height, and so it's quite possible that you can use a relatively longer top tube relative to frame height. For example, I'm only 5'3", but my pubic bone height is the same as yours. So you must be making up the extra 4 inches somewhere.

So maybe I should join Dr. Pete's freak show...

On the good side my next frame is going to be custom so I'm not worried...just figured I would check things out and low and behold, I'm a freak of nature... :eek:

Assuming your measurements are correct, you have a relatively short inseam (which is really pubic bone height) for your height, and so it's quite possible that you can use a relatively longer top tube relative to frame height. For example, I'm only 5'3", but my pubic bone height is the same as yours. So you must be making up the extra 4 inches somewhere.

Yeah, but you have a long femur. I have the same inseam as the OP and I am the same height.

Yeah, but you have a long femur. I have the same inseam as the OP and I am the same height.

lvleph, what framesize do you ride out of curiosity? 52ish?