[quote=mander][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):
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.[/quote]
As setback increases does stem length need to decrease?
[quote=JUGE FREDD]it’s the other way, that’s the whole point
sliding your butt back moves your shoulders down and forward[/quote]
this, but also it doesn’t really matter that much. you easily get >10cm of movement by changing your hand positions around the bars and hoods. most riders will be pretty adaptable to 1 or 2cm either way.
I had some sleepy hand issues and looked at the skeleton. I moved my saddle back maybe an inch, but I also raised it an inch.
I did a 65-mile ride yesterday with my lady. We were traveling around 15mph. My hands kept falling asleep and my lower back felt a bit sore.
Another internet fitter suggested my bars might be too low, but I don’t think they’re unreasonably so. Do I need to move my saddle back even further to continue to rotate my pelvis forward? Should I raise my bars?
im not fitter but seems like if you push the seat further back you’ll have to be even more horizontal which may be even more weight on arms and more crank in your neck
Get the position of the saddle sorted before anything up front.
I have my own version of the above.
Same thing, pedal up a small grade but ride with no hands and sitting upright (as tall as you can). I’ve also done this on my trainer with a healthy amount of resistance.
Bend from the hips maintaining a straight back until you are in your riding position, still no hands on the bars. I keep bending from the hips until i can’t bring my legs up and over the crank without any impediments (gut, rib cage etc). You will start speeding up which proves your weight is going to the pedals and assisting in putting out power. Shift into a bigger gear accordingly.
If you can hover in place putting out power (I like to use zone 3 power meter geek speak) then the saddle is likely in a good place. Same as what Kirk says, but I like to start from a different position.
Once the saddle is right you can now look at your reach to the bars. You should be able to reach your bars with about a 90deg upper arm with respect to your chest and your elbows bent. If you can’t now figure out your stem/bar/spacers.
All of this is what I strive for with a road fit. For me that means a bike I intend to ride with effort, not dicking around. I find myself pulling on the bars when at full throttle, not holding myself up by my hands at all.
[quote=ergott]Get the position of the saddle sorted before anything up front.
I have my own version of the above.
Same thing, pedal up a small grade but ride with no hands and sitting upright (as tall as you can). I’ve also done this on my trainer with a healthy amount of resistance.
Bend from the hips maintaining a straight back until you are in your riding position, still no hands on the bars. I keep bending from the hips until i can’t bring my legs up and over the crank without any impediments (gut, rib cage etc). You will start speeding up which proves your weight is going to the pedals and assisting in putting out power. Shift into a bigger gear accordingly.
If you can hover in place putting out power (I like to use zone 3 power meter geek speak) then the saddle is likely in a good place. Same as what Kirk says, but I like to start from a different position.
Once the saddle is right you can now look at your reach to the bars. You should be able to reach your bars with about a 90deg upper arm with respect to your chest and your elbows bent. If you can’t now figure out your stem/bar/spacers.
All of this is what I strive for with a road fit. For me that means a bike I intend to ride with effort, not dicking around. I find myself pulling on the bars when at full throttle, not holding myself up by my hands at all.[/quote]
ding ding ding
arms should only be supporting their own weight at the pace at which the bike is intended to be ridden.
That was gonna be my next question. The slower you go, the more upright your position will be, right? This means a bike set up for my CX pace will not be appropriately set up for a long slow ride at my wife’s pace. I don’t think this difference mattered much to me before, but now I’m getting old.
At any rate, I got into the habit of tilting my saddle up, but according to the skeletons, that inadvertently tipped my hips back. So I flattened my saddle again, dropped my seat height about half an inch, raised my bars about half an inch.
I went for a good hard ride and it felt a lot better. I definitely felt the pull against the bars, rather than supporting my weight on them.
Now that everything is shuffled around again, I’ll do your graded Zone 3 ride and see if I can’t fine tune it a bit more.
