Weight Weenie justification.

Questions about bike hire abroad and everything light bike related. No off-topic chat please

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by Weenie


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Arky
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by Arky

Good one. Loved the response to letter below as well.

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HammerTime2
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by HammerTime2

Top of the line “lightweight” carbon fiber bike is say 17 pounds? I guess that dude doesn't read WW very much.

roca rule
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by roca rule

that ingeniero miguel made me laugh 30 pound bike vs 17 obvious difference. now a 15 pound bike vs a 13 pound bike starts getting into the diminishing returns territory. the question is: don't engineers study physics as part of their majors?

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HammerTime2
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by HammerTime2

roca rule wrote:that ingeniero miguel made me laugh 30 pound bike vs 17 obvious difference. now a 15 pound bike vs a 13 pound bike starts getting into the diminishing returns territory. the question is: don't engineers study physics as part of their majors?
Most of them study physics for engineers, not physics for physicists. At top echelon schools in the honors courses, there's a difference.

xnavalav8r
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by xnavalav8r

My 8 year old is in second grade. Even he knows that he climbs faster on a lighter bike... all other things being equal.

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Arky
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by Arky

HammerTime2 wrote:
roca rule wrote:that ingeniero miguel made me laugh 30 pound bike vs 17 obvious difference. now a 15 pound bike vs a 13 pound bike starts getting into the diminishing returns territory. the question is: don't engineers study physics as part of their majors?
Most of them study physics for engineers, not physics for physicists. At top echelon schools in the honors courses, there's a difference.



What??? LOL

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horse
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by horse

That article states nothing other than the obvious.

"Weight Drag" seriously?

According to that article "weight drag" goes up with the incline. So on a flat there is no "weight drag." The total so called weight drag is simply the work done against gravity which happens on an incline.

You expect better from a frame builder, who really is expected to be a technical artisan.

A more interesting question is what happens on the flats. We know a lighter bike is advantageous when the road goes up. But what about on the flat? On the flat there is no work done against gravity. So, ideally, there is no difference between a light and a heavy bike on the flat. However acceleration matters and 2nd law of motion exemplifies the linear reciprocal relation between acceleration and mass (weight) for a given input from the rider.
Basically a bike twice as light (10lb vs 20lb) will accelerate twice as fast. A 15lb bike will accelerate only 1.3 times faster compared to a 20lb bike. It's only a LINEAR relation! Sorry to disappoint.

principiamacb
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by principiamacb

What about acceleration up a hill? :noidea:

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horse
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by horse

That's a straightforward argument too. You also take the component of the work done against gravity into account. Short of giving a few figures, the benefits of a light bike are well known when the road goes up. But tell me how steep you want to go? Alpe'Huez, Galibier, which sections?
On the flats a case in point had to be established.

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HammerTime2
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by HammerTime2

Arky wrote:
HammerTime2 wrote:
roca rule wrote:that ingeniero miguel made me laugh 30 pound bike vs 17 obvious difference. now a 15 pound bike vs a 13 pound bike starts getting into the diminishing returns territory. the question is: don't engineers study physics as part of their majors?
Most of them study physics for engineers, not physics for physicists. At top echelon schools in the honors courses, there's a difference.



What??? LOL

Physics for Engineers is generally a "baby" course compared to Physics for Physics/Math majors. Physics for Biology/Pre-Med is even more watered-down than Physics for Engineers. And then Physics for Poets is even more watered down than that. Some schools even have an Astronomy in effect for basket-weavers/video-game players/potheads which is even lower than Physics for Poets.

You reminded me of one of my math classes at school. There was this student in a hard core math class (for math majors) and he was one of the top students in the class. He was a EE major. As I used to say, he's EE* but he's good in math. This of course flies in the face of the popular misconception prevalent among laypeople that engineers are good at math.

* actually I said "he's 6-1, but he's good in math", and those in the know, will know what that means

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strobbekoen
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by strobbekoen

horse wrote:Basically a bike twice as light (10lb vs 20lb) will accelerate twice as fast. A 15lb bike will accelerate only 1.3 times faster compared to a 20lb bike. It's only a LINEAR relation! Sorry to disappoint.


Not the rider+bike.

Hamm: I guess you don't know there are different kind of engineers. Also, most specialize later on in their profession. If I were you, I would refrain from making blanket statements if you are neither a engineer or a physicist.

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horse
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by horse

You are correct. The rider+bike is what really counts and would make even less of a difference between a light and heavy bike. Not looking too promising with a WW bike is it.

outlaw105fan
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by outlaw105fan

HammerTime2 wrote:
roca rule wrote:that ingeniero miguel made me laugh 30 pound bike vs 17 obvious difference. now a 15 pound bike vs a 13 pound bike starts getting into the diminishing returns territory. the question is: don't engineers study physics as part of their majors?
Most of them study physics for engineers, not physics for physicists. At top echelon schools in the honors courses, there's a difference.


you pompous a-hole - I'll stack my engineering education against anything you have any damned day. Yes, there is a difference. Oh yeah I am from a top-echelon school but I don't rely on that when I pat myself on the back. I use the fact that I have numerous government (US) and commercial aerospace customers who love and are exceptionally happy with my engineering knowledge of physics and related areas.

by Weenie


sawyer
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by sawyer

strobbekoen wrote:
horse wrote:Basically a bike twice as light (10lb vs 20lb) will accelerate twice as fast. A 15lb bike will accelerate only 1.3 times faster compared to a 20lb bike. It's only a LINEAR relation! Sorry to disappoint.


Not the rider+bike.

Hamm: I guess you don't know there are different kind of engineers. Also, most specialize later on in their profession. If I were you, I would refrain from making blanket statements if you are neither a engineer or a physicist.



Yes, and aerodynamics aren't impacted by weight ...
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Stiff, Light, Aero - Pick Three!! :thumbup:

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