How stiffer bike has less energy lost

[novetan]

I heard abt the stiffer the bike, the lesser the energy will be lost thru your effort in peddling.

Assuming all things being equal, same rider, same wind direction, same wheel size, same road, etc. Below an example:

Assuming peddling at 90 rpm at gear 7 on a less stiffer bike, wheel rotates “x” no. of revolution/min and bike travels a distance of 700m/min. As compare with similar peddling at 90 rpm on a stiffer bike at gear 7, can I assume wheel should also rotates the same “x” nos. of rev/min that will result in the same distance travel of 700m.

I like to know how energy lose comes into play.

 

[Rob3rt]

I heard abt the stiffer the bike, the lesser the energy will be lost thru your effort in peddling.

Assuming all things being equal, same rider, same wind direction, same wheel size, same road, etc. Below an example:

Sssuming peddling at 90 rpm at gear 7 on a less stiffer bike, wheel rotates “x” no. of revolution/min and bike travels a distance of 700m/min. As compare with similar peddling at 90 rpm on a stiffer bike at gear 7, can I assume wheel should also rotates the same “x” nos. of rev/min that will result in the same distance travel of 700m.

I like to know how energy lose comes into play.

WTF is gear 7?

Also, energy is lost in frame flex, side to side twisting of the frame, thus power applied at the pedal is not equal the power delivered to the wheel. In a flexy frame the power input to do your 700m/min is greater than that on a frame that is stiffer (in the right places).

 

[novetan]

WTF is gear 7?

Can u be more civil. Do u understand what is meant by assumption?

 

[Rob3rt]

Can u be more civil. Do u understand what is meant by assumption?

Yes I do, I also understand the importance of clearly defining the theoretical problem, gear 7 could mean anything, it is a non-descriptive term.

 

[Peteaud]

Crankarms made of steel are better than those made of rubber.

Same with the frame holding the drive system.

Gears, rpm, wheel size has nothing to do with it.

Go up a hill on a road bike, now do the same on a full susser bso.

 

[MontyVeda]

...
Go up a hill on a road bike, now do the same on a full susser bso.

exactly... going up hill with front suspension is frustrating as a chunk of your pedal power squashes into the front fork and is lost.

 

[mickle]

... going up hill ... a chunk of your pedal power squashes into the front fork and is lost.

You sure about that?

 

[MontyVeda]

well... when i've ridden bikes with a front suspension fork, going up hill, i notice with each time i push down on the pedal, part of the fork sinks into itself... so yes, I'm sure about what I observe.

 

[Boris Bajic]

I didn't take all this stuff about rigidity at all seriously until I started to work on a Turbo.

I happen to like steel frames and prefer to ride on them.

But... get a little bored on a turbo and you end up looking at the bottom bracket.

Or... In a club session you look at the BBs of bikes around yours. You may be surprised.

The flex in a frame during a piece of work is quite extraordinary. I really had no idea until i saw it on a Turbo.

Carbon frames, particularly nice TT jobs, barely flex at all in comparison. All the work goes through the tyres.

Having said that, I still prefer steel to carbon - the soulless tool of the serious racer or the brag-accessory of the look-at-me faddist. I'm not an aspiring TdF rider and never was. Steel is lovely. Carbon is just carbon.

If you disagree, you are wrong.

 

[black'n'yellow]

Having said that, I still prefer steel to carbon - the soulless tool of the serious racer or the brag-accessory of the look-at-me faddist. I'm not an aspiring TdF rider and never was. Steel is lovely. Carbon is just carbon.

If you disagree, you are wrong.

I love a reasoned argument...

 

[apb]

Steel - the understatement of a purist.

 

[PpPete]

If you disagree, you are wrong.

 

[black'n'yellow]

Steel - the understatement of a purist.

purity can go screw itself - I'll take performance...

 

[apb]

purity can go screw itself - I'll take performance...

there is a good article by sheldon brown about frame material, which i came across when wondering why anyone would want to pay for titanium frame. The article is focused on frame materials in regards to touring, so carbon fiber only really gets a small mention.

It's an interesting read. and may answer a few questions around stiffness and when it is really required. For me a carbon fiber bike would be a waste.

aesthetics is probably a lot more important to people than they would like to admit and is the reason my bike isn't fluorescent.

http://sheldonbrown.com/frame-materials.html