Help me size my frame !

[killiandh10]

Hi everyone! 

I'm a bit new to cycling, currently riding a cheap triban bike, pretty heavy, weighed at 11.45kg, I'd like to buy a new frame to build a better bike
I'm not riding a lot yet, I'm running 8 times/week, but I start adding some cycling in my training plan with my coach.

I might increase the volume during the season, and why not try to do some races during the summer !
There is not much running races during summer so I think doing more cycling from april to summer could be something i'd keep above years.

Anyway, I did a static bike fit cause I was scared to not choose the right frame size  ,  as I'm always in between sizes when looking at rider height.
I'm about 177cm, so 5'10" for 68kg.

The bike shop gave me two report, with geometry for a comfort position and one or a competition position. I'm adding the pics.



I think i'll more look into the competition position, as my bike has been fitted according to this and I still feel pretty comfortable on the short rides I did (didn't ad the 20mm on stem yet).

What makes me doubt now, is that I see most people saying to go the lower size when you are in between.
However if I look at the stack, it's always way lower than I have on the report. Even when looking at the upper size, it's still lower and looks like I'll need spacers, but in this case i'm afraid not to have margin to lower the stack.

Do you think that the bike fit is reliable? it was shimano bike ft dynamic lab, smth like this (https://bikefitting.com/fr)
Or maybe that the position they gave me is not that agressive and I could go with lower stack ? Reach on most of these agressive frames are lower than on my report though

I was for example looking at speeder r55, winspace t1150-gen2 M (381 reach, 535 stack), or L (388 R, 560.5 S). Yoeleo r12 for 900€  looks like a really good option to me, as their sizing is in between with 54 frame (386 R, 550 S).
I Might go for this one, it's almost exactly in-between reach and stack of tarmac sl8, their calculator gives me either 54 or 56cmby  changing only 1cm.

Now there are some thing I'm not sure, for example, what stem length should I choose ? On the bike fit report I don't understand which reach of the handlebar is used. It looks like 80mm is standard but idk.
Also if the saddle has offset I should add this offset to the reach to calculate stem length ? A bit the same problem with less steep seat tube angle.

What I like on yoeleo is that we can choose between integrated handlebar and separated stem and bar. Integrated looks clean but I think that separate would be a more wise choice. As a beginner, i could easily try different fit, and maintenance would be easier, especially if I let cables outside. What do you think ?
a stem is only 20€ at decathlon, about the same weight as the carbon one though, so wondering why pay for a carbon.

But the handlebar coming separated is only 64mm reach, so i guess i should add 10mm to stem ? The longest is 120mm though...  .  As for angle,  it's 10°, a bit more than 7° on the one-piece, so it highers the stack ?

I'm trying to understand how geometry works 

I think I'll try to take a photo of myself on my bike with current position to see if I'm low. Because I'm in ideal stack according to the fit, but I don't feel like I am very low. Even if I lack 2cm on stem.
We could easily put me in the right position while my bike which is a triban rc500 M with endurance geometry, kinda weird.. 

Anyway, I'd appreciate any advice or suggestion about sizing or even frames
I already ordered the farsports wheelset

[klindsey00]

Typically stack and reach figures are from bottom bracket to the top of the headset. Nothing accounts for the stem/spacers/bar/brifters. Getting a bike fit should give you saddle height, saddle fore/aft and measurments to the hoods (probably some sort of stack/reach number in there) but you should be able to take those and see what frame size would allow you to get your saddle and hoods to the correct measurments for you with minimal spacers and such. Its all geometry, you can take the bike charts and make one with the size you are thinking and add on the bar/stem and do some calculations. Typically your body can take a lot of disfunction. If your stack is too low or reach is too long and your body feels like it is one of those it typically means you are WAY out of where you should be.

[Chiyou]

Yes, you could use geometry to find an answer to your questions. But first ask yourself, do I want to be an athlete or a mathlete? I know you want to be the former, and we all know that athletes are lazy, so instead of doing all sorts of complicated math do the lazy thing instead: ask the computer. Specifically, use CAD software to find the angle of the dangle and all that stuff. (I am not aware of an online bike fit calculator, so CAD it is.)

Based on the geometry chart for the Yoeleo R12 size 54 (and me not making any mistakes) it looks as if you need a 120mm stem (119.325 in the attached diagram) to get to your 'aggressive' fit. Also, you'd need about 60mm of steerer tube above the headset, maybe a bit more (that's the 59.8966 number). Roughly 35 to 40mm of that 60mm will be covered by the stem and the rest will have to be taken up by the headset cap and spacers.

60mm is arguably a bit much, especially if it turns out that you find the aggressive fit not that comfortable after all and wish to adopt a more relaxed position. As you say, you can use different stem degrees to raise/lower the handlebars but there is only so much you can adjust with that method. Maybe one size larger would be better; if you like, I can see how things shake out for a different frame - just let me know the model and size.

Two quick additional notes about stems: typically, you install stems in the negative direction, meaning that a -10 degree stem will sit lower than a -6 one. The attachment assumes a -7 degree stem.

If I have time tomorrow I'll try and answer some of your other questions.

[killiandh10]

Yes, you could use geometry to find an answer to your questions. But first ask yourself, do I want to be an athlete or a mathlete? I know you want to be the former, and we all know that athletes are lazy, so instead of doing all sorts of complicated math do the lazy thing instead: ask the computer. Specifically, use CAD software to find the angle of the dangle and all that stuff. (I am not aware of an online bike fit calculator, so CAD it is.)

Based on the geometry chart for the Yoeleo R12 size 54 (and me not making any mistakes) it looks as if you need a 120mm stem (119.325 in the attached diagram) to get to your 'aggressive' fit. Also, you'd need about 60mm of steerer tube above the headset, maybe a bit more (that's the 59.8966 number). Roughly 35 to 40mm of that 60mm will be covered by the stem and the rest will have to be taken up by the headset cap and spacers.

60mm is arguably a bit much, especially if it turns out that you find the aggressive fit not that comfortable after all and wish to adopt a more relaxed position. As you say, you can use different stem degrees to raise/lower the handlebars but there is only so much you can adjust with that method. Maybe one size larger would be better; if you like, I can see how things shake out for a different frame - just let me know the model and size.

Two quick additional notes about stems: typically, you install stems in the negative direction, meaning that a -10 degree stem will sit lower than a -6 one. The attachment assumes a -7 degree stem.

If I have time tomorrow I'll try and answer some of your other questions.

Wow thanks a lot for the CAD calculation based on yoleo r12. It helps me understanding geometry a bit more.

Thing went a bit fast this weekend and I already ordered a yoeleo r12 size 54 
But I had the same thought that I was going to neeed all spacers coming with it (38mm in total). because when you say the stem will take 35 to 40mm, shouldn't we cut it in half ? On the bike fit image they take the middle.

What I think a bit strange, is that accoding to height I am in between two size, according to the bike fit my measurement was pretty average for the height, but when looking at bikes geometry I'd need the larger size or even larger...

At the end you are right, yoeleo r12 54 might ne be that good because I have no margin to get a more comfortable position, for example winspace t1550 gen 2 size L has more stack then should be better for me.

I think I didn't take into consideration the head angle to choose the stem length.
I choosed a 100mm. I knew I was missing 2cm for my competition fit on my current bike, which has about 10mm less reach than the yoeleo, so i thought 100mm would be in-between.
Looks like it's 110mm which would be in-between. Maybe I should email them before it's shipped. I did the dummy things of choosing integrated bar so I rather decide fast haha.

I preferred to do in between because I though better be a bit less streched than too much. I can also still put back the saddle a bit, and the bar reach is 80, which is not on the smaller side and bar reach is not took under consideration in the fit!

Thanks a lot for the file, I guess i should download cad and do the same ! 
It's a bit late now as I already ordered haha. I think and hope the fit should be good overall, I paid slightly under 1000€ for the frame and bar, I think it's good value for money to have a bike to start being serious!

[klindsey00]

another thing is don't forget to account for the reach of the handlebars and shifters themselves, some could be 10-20mm longer/shorter than another

[glepore]

Quick response to the spacers question, depends on the stem angle entirely. -6, -17, 0, they'll all affect final bar height.

[killiandh10]

another thing is don't forget to account for the reach of the handlebars and shifters themselves, some could be 10-20mm longer/shorter than another

yep sure, I was saying that on the bike fit report it was not written,  but I just realised there the length from saddle to hood, and saddle to the end of stem.
So I could calculate it uses 135mm for bar+lever reach. This is about what i measured with tiagra lever and 80mm reach handlebar. 

[Chiyou]

when you say the stem will take 35 to 40mm, shouldn't we cut it in half ? On the bike fit image they take the middle.

You are correct, halving the value would best match the diagram. (I wasn't able to find the stack height for the integrated handlebars on Yoeleo's website - oh well.)

Just for general reference, here is a stem length calculator / comparison tool that allows you to see how different stems affect reach and height:
http://yojimg.net/bike/web_tools/stem.php

[killiandh10]

You are correct, halving the value would best match the diagram. (I wasn't able to find the stack height for the integrated handlebars on Yoeleo's website - oh well.)

Just for general reference, here is a stem length calculator / comparison tool that allows you to see how different stems affect reach and height:
http://yojimg.net/bike/web_tools/stem.php

So it looks like 38mm of spacer + 35mm of stem/2 =55,5mm
On the fit they have 52mm, but with a stack 26mm taller.
So basically, the bike will be about 2.5cm short according to the fit.

But looks like almost all bikes for my height have a similar stack, not much more.
I think and hope that it should be ok

Maybe I should keep the 100mm stem then ? Because I guess if the bar is a bit too low, having a bit less reach will compensate the position ?

 

[Chiyou]

So basically, the bike will be about 2.5cm short according to the fit.

Please note that the stem is effectively angled upward, which raises the handlebar position by ~20mm for a 120mm length stem (~17 for 100). I believe you'll be pretty close, perhaps 5 to 8mm lower than what your performance fit asks for.

Maybe I should keep the 100mm stem then ? Because I guess if the bar is a bit too low, having a bit less reach will compensate the position ?

I am thinking the opposite, actually: a lower position requires a longer stem compared to a more upright one. Imagine yourself sitting on the bike completely upright with a vertical back, then visualize how far your hands would be able to reach. Contrast that with sitting on the bike with a completely horizontal back, you'd be able to reach much further and accordingly would need a longer stem. But if you are feeling really stretched in the performance fit, going with a shorter stem would make sense.

[killiandh10]

Please note that the stem is effectively angled upward, which raises the handlebar position by ~20mm for a 120mm length stem (~17 for 100). I believe you'll be pretty close, perhaps 5 to 8mm lower than what your performance fit asks for.

Yes you are right, i re-did calculation later and realized it was a matter of some millimeters, depending on the stem 'stack'.

Anyway even though it's not shipped yet, it's ordered and I think that it should be ok.
At least there will be no excuse that my frame is to upper   I'll be the only to blame .  I don't think I'll be the guy who does a lot of really long rides so should be good, i'll get used to it anyway.
I emailed them to change stem for a 110, hoping it won't mess the order

I am thinking the opposite, actually: a lower position requires a longer stem compared to a more upright one. Imagine yourself sitting on the bike completely upright with a vertical back, then visualize how far your hands would be able to reach. Contrast that with sitting on the bike with a completely horizontal back, you'd be able to reach much further and accordingly would need a longer stem. But if you are feeling really stretched in the performance fit, going with a shorter stem would make sense.

Yes, I understand what you mean, you are right.
But I am thinking that this is to have the same "relative" reach, like your arm will be as far of your body with the longest stem on a lower position than on a higher stack with less reach.
Reach position will feel the same but in this case, you are more horizontal, with a more agressive position. That's why I thought, if your stack is lower, but you don't want to be more horizontal, like you want your torso to have the same angle to keep same, you need to also reduce the reach ?

Anyway thank you for all your replies, I appreciated very much.
I apologize for my english which is not the best, hoping I was not too painful to read

I downloaded a CAD open source software at work to try to do the same as you, but couldn't even figure out how to draw a line with length and angle  I gave up haha