Hi,

This seems a silly question but I am not sure, hence the question.

I have tight hamstrings which I have measured at 125 degrees (https://jomcrae.co.uk/bike-fit-blog-part-deux/ scroll down to testing your hamstrings) when I should be closer to 140-150 going by various fitting guidelines so I need to work on my flexibility.

Should I adjust my leg angle to 125 as this is my limit, and increase it bit by bit as my flexibility improves, or go by the guidelines and adjust it to 140?

I have found in the recent past that 140 gives me a lot of toe down, were as 125 feels better and has a more natural foot position but due to the low height the saddle is right back so reach is then a problem.

Do I go for 125, 140 or something else?

Cheers

Measure your bike inseam then multiply by .883 and set your seat height from center of crank to top of saddle at the post to that figure as a starting point.

I've done that before and it causes my toes to really point down due to the tight hamstrings in turn causing calf issues.

That is your starting point. Drop the saddle a little at a time until you are good. Actually, I thought I had the tightest hamstrings in the world, nice to know I am not alone.

I am guessing you have your handlebars pretty low - is that true? Maybe you need to keep your saddle up and raise your handlebars. You won't be able to ride a real aggressive position if you have really tight hammies (ignore that comment if it isn't applicable).

the question actually brings up an even greater/broader Question: Is the 'By the Formula/Numbers Pro Bike Fit going to provide a 'Better' Position for either performance or comfort (or both) ??? than 'trial and error' ??? or a combo of both ???

but back to your Q
the page you reference has a lot of holes, but no matter, let's consider your choices.

1. let's assume the goniometer measurement actually means something, and high level performance riders fall in the 140 to 155 deg range. If you set to 140, what advantages does this give you?
2. Counter that, what does 125 give you?

If, in fact, whatever your hamstring flexibility, it's only one important consideration. But let's say your Hammies are your limiting factor in leg extension. If you go much further, what happens? Your pedal stroke becomes a toe down 'digging' style, which greatly restricts your power at the lower end of the pedal stroke. Your hips rock on the saddle further causing not only power issues but also comfort problems. Too much extension and the pelvis has to remain very upright to allow that extension. Upright hip means you'll have a harder time getting into a more aero torso position - which further exacerbates your power and comfort. A high saddle position also means you have to move forward with the saddle, which means further adaptation with the bars... and more importantly makes it difficult to get good engagement of the gluts without good reworking of position.

So really, any 'formula' is gonna give a rider with flexibility limitations a hard fit. That's why formulas are just 'start' placement; then you gotta work it to the individual.

My recomendations
take the leg extension info, your goniometer reading as acknowledgement that you can improve flexibility - as a target for improvment.

set the saddle height for yourself, as high as you can:
a. in conjunction with a saddle fore/aft which gets good torso balance and allows you to have as much pelvis angle as the legs/hip/nback will allow - at this point I don;t think you could overdo plevic tilt angle - so max it out.
b. your foot angle at the bottom of the pedal stroke is the same as the foot angle of the forward female rider (in yellow/orange) in the pic of the website you link to above. It may seem parallet to the ground, but it's actually just ever so slighty toe down...
c. your hips don;t rock while pedaling.
d. your feet are connectign with the pedals as 'flat' as possible, which also takes into account cleat rotation.

Then work on your flexibility - not just hamstrings, but overall, leg/hip/back and overall torso if you can...
and over extended time - months, slowly raise seat height as your flexibility increases. Riding is about using the assets you have at the time you're actually in the saddle, not what you hope to have, down the road.

Thanks for the informative post, it basically sums up things nicely

My foot angel is basically the same as that rider, I was trying to do the same foot position as it looked right, although torso wise no way can I do that, yet.

Bar wise it is already up as high as it will go... FYI I have a Giant TCR Advanced, so in general its a more racey position and a slightly longer reach than more sportive type bikes... but thankfully I have a winter bike with more relaxed angles so I will stick to that until things improve...

I am now doing daily stretching/yoga to help, but understand its not a quick win, but hopefully come Spring I will be around the 140 or so range.

But I will do as your point out, thanks again for the help.

do note that my reference to that female rider was only for foot angle, not pelvic tilt - IMO she could do with more tilt...
just a few mm down with the saddle and she could likely find more power, scotty...
like this guy - fabulous, classic position - da kine

consider his pelvic angle, leg angle, flat back...
BTW, does this look like 150 ??? I don;t think so... riders are different, all this differs, but the pelvic angle seems very familiar...

The cannibal eats up the Hr record