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FIT ? - Stack and Reach
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I have read the articles and searched the forums. It appears to me that the only way I can learn my personal stack and reach numbers is to go have a FIST fit done. Is that the correct understanding?

Is there a calculator where you can input body measurements and it could give a stack and reach like the competitive cyclist fit calculator?

Im trying to figure out if I need long and low or narrow and tall. Currently my seat is at 78.5 cm from BB (79.2 felt to high, have ridden with new height for several weeks and will raise it again to 79). My pad drop is slightly more than moderate.

Please forgive the ignorance.

Semi relevant numbers (Maybe slightly off since I did it at home but should be close +/- 5mm)
Gender M Inseam 88 cm Trunk 68 cm Forearm 35.5 cm Arm 64.5 cm Thigh 62 cm Lower Leg 55 cm Sternal Notch 150 cm Total Body Height 181 cm
Top Tube Range 53.3 - 55.3 Stem Length Range 8.0 - 10.0 Saddle-Bottom Bracket Position 79.2 Saddle-Pedal Position 96.4 Saddle-Ground Position 104.2 Cranklength 175.0 Aero Bar Size M Saddle-Aero Bar Pad Drop Minimal 7.6 Saddle-Aero Bar Pad Drop Moderate 13.1 Saddle-Aero Bar Pad Drop Intense 15.5 Saddle-Aero Bar Pad Drop Maximal 19.5 Pad-Ground Position Minimal 96.6 Pad-Ground Position Moderate 91.1 Pad-Ground Position Intense 88.7 Pad-Ground Position Maximal 84.7
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Re: FIT ? - Stack and Reach [~C] [ In reply to ]
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I have read the articles and searched the forums. It appears to me that the only way I can learn my personal stack and reach numbers is to go have a FIST fit done. Is that the correct understanding?

Yes. That is the only truly accurate way.

Quote:
Is there a calculator where you can input body measurements and it could give a stack and reach like the competitive cyclist fit calculator?

No. Dan & I developed a static fit system, the details of which and the limitations of which are described here: http://www.slowtwitch.com/...-fit_system_890.html

The only numbers you need for the above are your overall height and your inseam.

"Non est ad astra mollis e terris via." - Seneca | rappstar.com | FB - Rappstar Racing | IG - @jordanrapp
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Re: FIT ? - Stack and Reach [Rappstar] [ In reply to ]
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Thanks for the reply. In relation to long legs vs long torso is there any type of chart that would indicate what average is for a given height to figure where a person falls on either side of average? Or is there a particular ratio of legs/torso that your looking for?
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Re: FIT ? - Stack and Reach [~C] [ In reply to ]
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That's in the article. In other words, it doesn't really matter what side of the ratio you fall on. From the article I linked to.

Cockpit distance

This is a function of your torso length. In other static systems, it's measured "crotch to notch": where the inseam stops to the depression just below your adam's apple, just above your clavicle.

But we aren't measuring that way. We're taking as axiomatic a truism we've often found, that a rider of average proportion, fit properly, will have a cockpit distance equal to his saddle height. So, that distance from BB axle to the top of the saddle (halfway between the saddle's fore and aft) will equal the distance from the saddle nose to the pivot bolt on the bar end shifter.

But, on a longer torso'd person the cockpit distance would be longer than the saddle height; on a long-legged person the saddle height would be longer than the cockpit distance. We consider the saddle height as a function of your overall height, determine whether you're leg-long or torso-long, and calculate your cockpit based on saddle height and this leg:torso ratio. The equation we've derived is this:

E = .72H - .67D

E = cockpit
H = overall rider height
D = saddle height

"Non est ad astra mollis e terris via." - Seneca | rappstar.com | FB - Rappstar Racing | IG - @jordanrapp
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Re: FIT ? - Stack and Reach [~C] [ In reply to ]
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~C wrote:
I have read the articles and searched the forums. It appears to me that the only way I can learn my personal stack and reach numbers is to go have a FIST fit done. Is that the correct understanding?

No, you could fit yourself, or have any number of other methodologies/people fit you. FIST is not the only way.

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Is there a calculator where you can input body measurements and it could give a stack and reach like the competitive cyclist fit calculator?

No, because it depends on the position you want to/can ride in as well.


The two best options are generally:

1. find a good fitter who can help you find a decent position in a few hours, figure out a good range of stack/reach that will work for that position, then go buy a frame.

2. make a wild guess at the stack and reach you will need, buy a cheap used frame, ride it, play with your position for a season or so to figure it out, then next season buy an expensive frame.

or some combination of the above.



Kat Hunter reports on the San Dimas Stage Race from inside the GC winning team
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter
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Re: FIT ? - Stack and Reach [Rappstar] [ In reply to ]
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Thanks,

Im beginning the understand the methodology now.

I set up an excel sheet with my measurements and the calculations in the articles. My saddle height according the competitive cyclist fit cal was 79.2 and using the .885*inseam mine is 77.8 which definitely is closer to "feeling" right. I might be a few mm to high at the moment will drop it down and see what it does to my power. I do see that as a significant difference between the two.

Using that height it is interesting that I had my cockpit length was already set to with in 2mm of what the calculations said it should be.
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