[Diego Hemken]

I got a road bike recently and I found the geometry of the relevant body parts to be confusing. Obviously, optimizing the geometry would yield a great advantage in speed, endurance, comfort, and injury. And there seems to be a ubiquitous standard for optimal geometry. But it seems to me like this standard isn't optimal. And I am frankly surprised by the lack in variance from the standard.

I can sprint faster on a bike when I am off the saddle and my hip joint is more forward than it is when I'm seated on the saddle. Why aren't bikes designed with the saddle in that position in the first place?

The main points are the relative positions of the crankshaft, hip joint, and hands. I feel like if I could bend my bike frame to a much different shape I would.

Any comments?

 

[RaptorTC]

Sounds like you'd get along well with Graeme Obree. He tried to mess with traditional bike geometry and the UCI put the kibosh on it.

 

[JoelS]

Yeah. There seems to be a current "standard" as far as much of the geometry goes. Many of the available frames fall into this. Sometimes the only way to get exactly what you want is to go custom.

 

[wim]

Why aren't bikes designed with the saddle in that position in the first place?

Because during a bicycle ride or race, you only ride standing up for a very small percentage of total ride time. When sitting down, the normal saddle position is, in fact, the optimal one.

Your proposal would make sense if people rode standing up all the time, like an entire century. I can't imagine myself doing that, but I have seen someone ride 70 miles standing up on a bike without a saddle or seatpost. There was no explanation when asked, so there must have been a very personal or perhaps embarrassing reason.

 

[Jay Strongbow]

I got a road bike recently and I found the geometry of the relevant body parts to be confusing. Obviously, optimizing the geometry would yield a great advantage in speed, endurance, comfort, and injury. And there seems to be a ubiquitous standard for optimal geometry. But it seems to me like this standard isn't optimal. And I am frankly surprised by the lack in variance from the standard.

I can sprint faster on a bike when I am off the saddle and my hip joint is more forward than it is when I'm seated on the saddle. Why aren't bikes designed with the saddle in that position in the first place?

The main points are the relative positions of the crankshaft, hip joint, and hands. I feel like if I could bend my bike frame to a much different shape I would.

Any comments?

Great. Now try it with a saddle in a fixed position between your legs.

And what wim said.

I smell troll but whatever.

 

[Mr Evil]

Maybe you want a tri bike?

 

[JCavilia]

From your thread title I thought we were gonna be talking math. Non-euclidian higher-dimensional and stuff. Oh, well . . .

I question your whole premise, but if you want to experiment you don't have to build a different frame shape. There's a lot of adjustment possible of relative positions of saddle, bb and bars. You can change stem length and height, get a seatpost with no offset, all kinds of stuff.

 

[cbk57]

There are a couple issues with the initial point relative to sprinting. The foreword position you are thinking of is variable as you are moving relative to your point of balance as you stand and sprint. I had some coaching from a track sprinter that advocated a front to back motion in the sprint. So that you are lunging foreword on your foreword peddle stroke. It is just not as simple as moving the saddle to where you would be in a sprint.

I personally find a foreword position to be very uncomfortable and feel out of balance on the bike when seated and that is just moving the saddle foreword about an inch. I would not want to spend hours that far foreword. A sprint is only 300 meters give or take a bit.

 

[vmps]

You'll squash your junk.

 

[Kerry Irons]

From your thread title I thought we were gonna be talking math. Non-euclidian higher-dimensional and stuff.

First thing I thought of was that "new math" that was all the rage when I started 7th grade. Yes, that was a LONG time ago.