Humerus length affecting bike fit

Triathlon Forum
1

Ok, I have potentially a silly question but I think not…

I have spent waaaayy too much time trying to understand how I fit into dan’s view of the fitting universe.

Background:
long arms, long legs, wide shoulders, short torso, 6’0, wingspan (fingertip to fingertip is 6’4), 33inch inseam

Here’s my question:

How does humerus length affect bike fit? If i’m understanding everything correctly, a long humerus is going to allow me to have a more open hip angle for any given seat position. Since seat angle is used in combination with hip angle to determine appropriate fit, my takeaway is that I should be able to ride steeper comfortably than someone with shorter arms.

Or, I may be getting this wrong and I’m not riding any steeper, just riding with more drop.

which is it? And how far off track am I?

as near as I can figure I’m riding at 77.5 degrees with 9.5 cm of drop, and I look like I’m practically riding a road bike… ex swimmer so think “lat wings”. NOT aerodynamic.

2

Humerus not humerous
one is a bone one is almost an adjective
.

3

I see lots of people saying “ride steep at 78 or 82 degrees”. Thats steep? I ride 5cm in front of the bottom bracket and spend nearly 90% of the time on the tip of the saddle. I figure I’m close to 90 degrees. I’m also have long arms, long legs (37" inseam), short torso at 6’-3". I ride about 18cm of drop and I’m not even close to flat! As you move forward the bars can go down, as you are opening up the hip to torso angle as you go forward.

4

maybe Dan can chime in? How does arm length play into the hip angle/seat angle situation?

5

Your humerus length should not affect your ideal seat angle. All it means is that you need to have your bars lower at any given seat angle in order to achieve the same hip angle as if you had a shorter humerus.

6

Yep.