Compendium of Internet Fit Advice


#1021

Maybe that?


#1022

Yeah, that shape is very close to a Cowbell - if it were 135/85 instead of 120/73 I’d be all over it.

I’m thinking that the problem may be biomechanical, that I need to do some shoulder openers before and during a ride. It’s certainly cheaper and less of a hassle than replacing bars.


#1023

Is there an alternative other than

  • more setback
  • shorter stem
  • rusty stack
    for getting weight off the hands?
    Just wanna make sure I’m thinking about this the right way

#1024

More setback
Longer stem
Core exercises
Higher bars
Shorter stem only if you increase setback by like cm. Weight on hands is from your body not being far forward enough to engage your core, so moving the bars further, with a strong enough core, reduces weight on the hands. Think of your body as a cantilever


#1025

that seems wrong
I thought you wanted to keep yr center of mass above the pedals
so
doesn’t butt back = hands forward
and butt forward = hands back?

if I kept the saddle in the same place and moved the bars forward
that would put more mass in front of the pedals
which would put more weight on my hands

This is making me feel dumb

my core is plenty strong


#1026

More power to the pedals means less on your upper body. Ride faster.


#1027

What does center of mass over pedals have to do with too much weight on your hands? Moving the grips farther from your shoulders lets your core do more of the work.


#1028

can you draw us a free body diagram?


#1029

pushing down on the pedals creates a moment wanting to rotate your body backwards around the saddle. The harder you pedal, the more you unweight your upper body, like what ergott said. The more setback you have, the larger the moment caused by pedaling.

longer reach is good because it lets you tilt your pelvis forward and extend your back + neck into a more natural position (excerpt from an academic paper I found a while back):


#1030

Also, bikes are designed for different things, so the appropriate position of the bars saddle, and pedals will change based on the desired body position. Your bike fit is a result of the intended use of the bike, not a result of how you’re feeling on the thing. There’s a reason why the aero position is rotated way forward, and rivendell couches have super long head tubes.


#1031

Additionally, closing up the hip angle tends to make more power come from the glutes versus quads, which increases the rotating moment derived from pedaling, offsetting the torque you expected to come from flattening the torso, and glutes come on earlier in the pedal stroke which leads to more of a rearward thrust coming from the pedal, also offsetting the arm load

It’s not like gravity doesn’t matter to weight distribution – If the action of gravity on the body isn’t one of the inputs determining weight distribution, then TT bikes wouldn’t have elbow rests and recumbents wouldn’t have backrests. And if you’re thinking in terms of reach, drop and setback, then the direction of gravity is already featured in your conceptual framework.

It’s more like gravity is one out of many factors and there are countering factors that are also activated when you tweak one geo parameter. And any bike position is always a satisficing between aero, fatigue, power, maneuverability, etc,. Stuff like TT bikes are in some sense easier to think about because you get to dial power and aero to 100 and what is non-straight-line handling or comfort. If you insist on balancing more than two parameters to make some kind of generally useful bike, you end up in a place where half the factors are balancing out the other half and intuitions are hard.


#1032

By opening and closing, you mean increasing or decreasing the angle between the legs and torso?


#1033

[quote=joy of vaping]pushing down on the pedals creates a moment wanting to rotate your body backwards around the saddle. The harder you pedal, the more you unweight your upper body, like what ergott said. The more setback you have, the larger the moment caused by pedaling.

longer reach is good because it lets you tilt your pelvis forward and extend your back + neck into a more natural position (excerpt from an academic paper I found a while back):

[/quote]

omg i remember those skeletons. Ive been wanting to see that again since you last posted it, just couldn’t find it. Thanks and i will be adding this to the spreadsheet.


#1034

Right, opening meaning larger angle.


#1035


Any glaring problems?


#1036

THE LEFT WHEEL IS MOUNTED SIDEWAYS!!!


#1037

measuring Stack/Reach to the bottom of the headtube is glaringly unusual

but kinda genius, it makes that Reach actually an independent fit measurement instead of also changing with HT Length


#1038

That’s what I was looking for in a framebuilder - glaringly unusual but kinda genius.
Really liked the Bantam Allroad stuff as well. Very cool straight blade low trail fork on that one.


#1039


#1040

STORN