New version V8. Biomechanical & sizing & fitting spreadsheet

A light bike doesn't replace good fitness.

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pave
Posts: 34
Joined: Tue Mar 11, 2008 3:18 pm
Location: Rijeka, Croatia

by pave

Hi guys, I would appreciate any insight you might have about my position. I just lowered my seat about a cm. I'm 190cm with 87cm inseam. The frame is a size 60 canyon, seat tube 589mm top tube 571, head tub 188. Stem is 105mm. I recently got injured during a hard training, Back side of the right knee hurts when pulling back and the quadriceps around the knee on the inside of the leg when pushing down. Friend's suggested that my seat was to high so i lowered it and took these images.

Any kind of info is very appreciated, thank you.
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by Weenie


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beatnik
Posts: 1237
Joined: Thu Aug 03, 2006 6:38 pm

by beatnik

Value in flexibility must be numerical, it´s a mistake. But it must work also with text format, if it doesn´t just change the format to number. Flexibility level determines your best handlebar reach and stem, but nothing else. The more flexible you are, the more aero position you can ride, with less stress for your back.

For the one with knee pain, i think saddle setback is your problem, just fit it as the s.s. recommends. a.f.a i see in pictures it´s not 9.4 cm, it´s hard to figure out, but i´d swear it´s no more than 7cm.






Regards.
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P4264823.JPG
Biomechanical spreadsheet. Sizing&Fitting.

http://weightweenies.starbike.com/forum ... 8e319d185b

Burning Dogma
Posts: 161
Joined: Sat Oct 04, 2008 5:14 pm
Location: Portugal

by Burning Dogma

I've set my saddle height and setback according to this spreadsheet. Then I measured the distance between saddle nose and handlebar and is about 57cms while the spreadsheet recommends about 53cms. Is there anything I'm doing wrong?

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eurperg
Posts: 789
Joined: Mon May 14, 2007 10:32 am
Location: Finland

by eurperg

The spreadsheet gives me similar of my current bike, but the toptube it suggests is 1,5 cm shorter than I'm currently using, and the saddle height is 2cm more than what I'm using.

My measurements:

Length: 184 cm
Inseam: 92 cm
Elbow-middlefinger: 49 cm
Flexibility: 7


I have now a 57 cm toptube with 100 mm stem, and I'm close to banging my knees to handlebars already when climbing out of saddle!
The spreadsheet gives me 55,5 top tube and 60,1 seat tube.

Reach from saddle tip to center of bars is now 56 cm in my bike, funny how some 6ft long pros have that even 8 cm longer...

I have 9 cm setback, 9,5 cm drop, almost what the spreadsheet suggests. (9,9 / 9,4)

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Koen
Posts: 343
Joined: Thu Sep 07, 2006 6:31 pm
Location: Aalst (Belgium)

by Koen

why isn't the upper arm included in measuring arm length? I have very small hands, so that ellebow-middle finger measurement is only 46cms. Know i don't have long arms, but i think it's my small hand that messes with the whole arm length.
btw i'm 1m80 and have 85.5 inseam. If i run the measurements in your excel file, then I'm stunned:
Currently i ride with a 14cm stem with setback of the saddle, and my 'results' are 6.6cm stem with setback? I know i'm overstretching a bit, but it's such a huge difference
i posted some pics to make things clear:
http://img168.imageshack.us/gal.php?g=dsc01494c.jpg
Gewoon bluve goan!

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beatnik
Posts: 1237
Joined: Thu Aug 03, 2006 6:38 pm

by beatnik

Koen : Your reach is too long, you need a 9 cm stem ( 8.6 suggested). You don´t need a setback seatpost, or if you have one you are not going to install the saddle just in the middle of its rails because your saddle heigth gives you enough setback.

euperg: I explaned it before. Best stem is an aproach related with your best t.tube length, for a 10 cm stem and saddle in the center of its rails. There is no other way to do it.

Burning: You need another stem to fit your bike ;).

As i told before, you need a bit of common sense. Keep your measures is a reasonable margin. Stem is the only way to fit an standard geometry frame properly. We all have diferent body sizes, and they only make standard geometries.

Note: Just be careful and patient measuring your body. Take your time.
Biomechanical spreadsheet. Sizing&Fitting.

http://weightweenies.starbike.com/forum ... 8e319d185b

jever98
Posts: 809
Joined: Wed Feb 18, 2009 12:02 pm

by jever98

Hi Beatnik,

to follow up on an earlier question - do you happen to have guidance on fitting for a triathlon type frame?

Thanks and best
Jever

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beatnik
Posts: 1237
Joined: Thu Aug 03, 2006 6:38 pm

by beatnik

jever98 wrote:Hi Beatnik,

to follow up on an earlier question - do you happen to have guidance on fitting for a triathlon type frame?

Thanks and best
Jever


No i don´t. I guess you ride as a time trialist, and well...it´s a long story, but zero setback and short efforts in flat roads obviously need another fit. I´m sorry.
Biomechanical spreadsheet. Sizing&Fitting.

http://weightweenies.starbike.com/forum ... 8e319d185b

jever98
Posts: 809
Joined: Wed Feb 18, 2009 12:02 pm

by jever98

actually, I am looking to build a triathlon bike for long rides... Difficult to know the right frame length and height. Slowtwitch has a formula for recommended handlebar drop, but I cannot figure out how long the frame should be :-/.

Cheers
Jever

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beatnik
Posts: 1237
Joined: Thu Aug 03, 2006 6:38 pm

by beatnik

Reach from saddle tip to center of bars is now 56 cm in my bike, funny how some 6ft long pros have that even 8 cm longer...


Pros are in the top of the flexibility chart, and well, as you say height is not the best way to fit a bike.
Biomechanical spreadsheet. Sizing&Fitting.

http://weightweenies.starbike.com/forum ... 8e319d185b

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beatnik
Posts: 1237
Joined: Thu Aug 03, 2006 6:38 pm

by beatnik

jever98 wrote:actually, I am looking to build a triathlon bike for long rides... Difficult to know the right frame length and height. Slowtwitch has a formula for recommended handlebar drop, but I cannot figure out how long the frame should be :-/.

Cheers
Jever


http://bikesportmichigan.com/bikes/karma.shtml
http://bikesportmichigan.com/bikes/difference.shtml

Hope you find them useful.
Biomechanical spreadsheet. Sizing&Fitting.

http://weightweenies.starbike.com/forum ... 8e319d185b

Burning Dogma
Posts: 161
Joined: Sat Oct 04, 2008 5:14 pm
Location: Portugal

by Burning Dogma

Shouldn't saddle lenght affect setback? I've switched from SLR to an Arione and sit in the rear of the Arione (widdest part). To use 8.3cm setback that spreadsheet tells, my saddle is all way back in a setback seatpost. But I think my back is too much flat. Since the Arione is longer than the SLR, setback shouldn't be a bit less?

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beatnik
Posts: 1237
Joined: Thu Aug 03, 2006 6:38 pm

by beatnik

Burning Dogma wrote:Shouldn't saddle lenght affect setback? I've switched from SLR to an Arione and sit in the rear of the Arione (widdest part). To use 8.3cm setback that spreadsheet tells, my saddle is all way back in a setback seatpost. But I think my back is too much flat. Since the Arione is longer than the SLR, setback shouldn't be a bit less?


Use your common sense ;), if you sit in the rear and the saddle is longer, the setback should be shorter ;). Just measure the setback including your saddle.

8.3+28(SLR)=36.3
8.3+30 (Arione)= 38.3

So 2 cm less for the saddle nose - b.bracket axis distance is needed if you fix your saddle all the way back.
Biomechanical spreadsheet. Sizing&Fitting.

http://weightweenies.starbike.com/forum ... 8e319d185b

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beatnik
Posts: 1237
Joined: Thu Aug 03, 2006 6:38 pm

by beatnik

Is not in the s.s. but i want to tell you something. Buy a SMP saddle, the only one that gives a 100% of blood at your perineum.

For S sized riders= Evolution
For M riders= Glider
For L-XL riders= Pro
For XL-XXL riders= Plus

www.sellesmp.com

After 25 years of cycling these are best saddles your money can buy. I´m not a commercial but this saddle has completely transformed my riding experience.
Biomechanical spreadsheet. Sizing&Fitting.

http://weightweenies.starbike.com/forum ... 8e319d185b

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coloclimber
Moderator
Posts: 2943
Joined: Wed Aug 23, 2006 9:11 pm
Location: People's Republic of Boulder

by coloclimber

beatnik wrote: this saddle has completely transformed my riding experience.

Care to explain how?? thx
-Deacon Doctor Colorado Slim

by Weenie


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