Just a few questions...

How have you worked out that length of your fore arm equates to or is relative to the length of your torso???

I appreciate that fore arm length has SOMETHING to do with reach adjustment but it is not the ONLY measurement to be taken into consideration when fitting a bike.

How have you worked out the crank length part of your calculator?? Apparently, in order to be running 175mm cranks (a size of crank that is found on most stock bikes above the 56cm size range!!!) I need to have size 50EU feet!!!

How is it that a 100mm is "perfect" when you haven't taken into account the size/height of the rider??? Larger bikes require longer stems to ensure better weight distribution over the bike.

In my experience this sort of calculator is seldom correct as there are too many factors to take into account.. eg. age, riding style, torso length, arm length bla bla bla. You can't generalise the fitting of a bike because everybody is different. I appreciate that this is just a guide but you have contradicted your own calculator earlier in this thread by saying you ride a 58cm bike - when i input your data I get 56.5??!?!?!

Beatnik: Thanks for the reply. In the end it all comes down to "feel" but I just wanted to clarify which system you were basing your equations on. Ended up with a 3mm lower saddle height than what the system recommended. Either way, very close!

Capo: I was very sceptical when I first ran across Beatnik's system. Just for fun I decided to try it out. Guess what? It worked very well for ME. Had everything checked by a well-renowned fitter and he agreed. Try it, you may like it.

Just remember, do you want to LOOK good or do you want to FEEL good?


Cheers

Cobbles

Cobbles,

I may have come across sceptical but im not rubbishing the idea. I dont mean to create the impression that it doesn't work but I have tried it on me and a few of my colleagues and we all found that it didn't match our requirements. I have to say that calculators such as this one are very general and must be taken with a pinch of salt. As for looking good who gives a damn thats irrelevant when you're sprinting in the middle of the pack!!!

I found this calculator to be terrible. It said I need a size 52 frame, and should run a 75mm stem on my 58. I'm 190 cm tall and currently ride a 58 with a 140, which feels too small.

I guess is my mistake, because pictures aren´t good, specially for you arm length measure. Try it this way (PICTURE BELOW), and give us your feedback .

Hope you like the new version .



http://www.mediafire.com/file/5xnxnyynzih/Biomechanicalcyclingv8english.zip

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Biomechanical spreadsheet. Sizing&Fitting.

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

Beatnick, it's saying it's got a broken link for me?
Is it ok for everyone else?

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Guildford/Woking is the home of F1.
We make loads of other stuff here too.

no dice...bad link for the new spreadsheet...

Now is fixed i hope.

For CapoBoy: Your self conviction exercise is good, but torso length could also be considered if you want, nevertheless, there is a fixed proportion, and it´s unnecessary. I could just put it in my s.s. but i don´t. If you want to measure it i could tell you how, but once you have promediate you will find less than 1-2 cm of variation in 15% of the cases.

Regards

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Biomechanical spreadsheet. Sizing&Fitting.

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

It´s my last version. Regards.

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Biomechanical spreadsheet. Sizing&Fitting.

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

It’s a great one to go out on!

Thanks for providing the spreadsheets, Beatnik. I've found them really useful.

For mtb riders, just another question, you must consider your fork´s sag when you measure the saddle - handlebar height. Once you are pedalling with the fork locked the drop is increased around 2-3 cm . If you suffer low back pain, just check it, is not a minor issue. Put a gum around the fork bar and sit, the gum´s displacement gives you the sag. Regards

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Biomechanical spreadsheet. Sizing&Fitting.

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

Surely 1-2 cm variation is quite a lot considering most bike companies have 2 cm incremental frame sizes,therefore (if I have read your measurements correctly) it would be quite easy to end up getting the wrong frame size, which would be disappointing and costly.

I have explaned it before, torso length is included, but you can measure it. Sit in a chair with more or less same angle in your trunk that you have when you are pedalling, and measure the distance between your hip top end and the top of shoulder . Now you must promediate it with your elbow middle finger distance and put it in the s.s. to have the perfect fit. ¿Magic?...no, just observation. I can put it in the s.s. but is not necessary as i told before, and it´s not an easy measurement, because you have to know how measure it correctly and a picture could not be enough to show you how, that´s the reason i choose the esiaset way for the user.

Please just check my measurements for a while, and don´t be virtual cyclists. The new virtual world is plenty of virtual things, but cycling is real, i don´t want everbody to be fitted as i told, but i´m sure if you give it a chance, you will remember me for a long time

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Biomechanical spreadsheet. Sizing&Fitting.

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

Should the saddle height from the spreadsheet be taken up the seat tube to the top of the saddle? or to the "100mm + 40mm" type point on the top of the saddle?

If you have a bit of setback this seems to give pretty different measures.

I came across this Biomechanical Spreadsheet and decided to compare it to my own set up and the Competitive Cyclist Competitive Fit:

My Measurements:
Inseam = 81.3 cm
Trunk = 61.0 cm
Forearm = 33.7 cm
Arm = 62.9 cm
Thigh = 58.4 cm
Lower Leg = 53.7 cm
Sternal Notch = 144.8 cm
Total Body Height = 174.6 cm
Elbow-Middle Finger = 47.0 cm

Biomechanical Spreadsheet (cm)
Top Tube = 53.5
Stem = 9.6
BB-Saddle = 72.3
Saddle-Handlebar = 51.0
Drop = 6.7 +/- 1 cm
Saddle Setback = 7.2

Competitive Fit (cm)
Top Tube = 53.1-53.5
Stem = 10.7-11.3
BB-Saddle = 72.9-74.9
Saddle-Handlebar = 50.8-51.4
Drop = N/A
Saddle Setback = 4.2-4.6

My Set Up (cm)
Top Tube = 53.5
Stem = 11.0
BB-Saddle = 73.6
Saddle-Handlebar = 50.8
Drop = 7.6
Saddle Setback = 4.4

Almost every variable is surprisingly close. The only variable that looks out of range is the amount of saddle setback. I checked the knee-over-spindle with a plumb bob and it looks like I could move my saddle back so that my setback would increase by 1.3 cm to 5.7 cm. That would put my saddle-handlebar distance to 51.8 cm, so I would need to go from 110 mm to a 100 mm stem to put my saddle-handlebar distance back to 50.8 cm.

Interesting comparing these variables. I am comfortable with my current fit but I may try experimenting with the increased setback and shorter stem to see if it feels better and I get more power output. Maybe it is time for a professional fit.

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It's all downhill from here, except for the uphills.