Does rotating weight really matter?
#26
Senior Member
It matters for acceleration since you not only have to accelerate the wheel mass forward with the rest of the bicycle, but you also have to add rotational energy to the wheels. And the rotational (angular) energy grows with the square of the rotational speed (angular velocity). (For the technical people, there is an w^2 factor where w=omega.) Forward kinetic energy only grows linearly with speed.
#27
Senior Member
In racing and all else equal, lighter IS better. At the same power you accelerate and ascend faster. Period. However the penalty for adding a few hundred grams or even a kg is small and nothing that will spoil your Sunday ride. And saving a few aero watts is arguably more beneficial than saving a pound of weight, for most riding at least.
#28
Senior Member
The basic difference between added weight or added rolling and wind resistance is analogue to the difference between a capacitor and a resistor. The former (weight) stores energy, but releases it again, whereas the latter (rolling and wind resistance) convert energy into heat and looses it.
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#31
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If you're interested in science, learn to ask a proper question. Of course rotating weight makes a difference, but then again everything makes some difference. The question is either how much of a difference does it make, or is the difference greater than some specified threshold.
#32
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Let's talk about cassettes.. I don't think they qualify as rotating weight, since they only rotate when pedaling, correct? There'd be no stored kinetic energy, or is there? Same for cranks?
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There is some stored kinetic energy there, but (unlike the energy stored in wheels) it gets "thrown away" when you stop pedalling.
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I tried a lighter carbon wheel set a couple of years ago, and found no gain. They felt different but in the end, no noticeable speed gain. For me, at least, a total waste. I'll stick with my Roval SLX 24 wheels.
#38
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True :-)
In racing and all else equal, lighter IS better. At the same power you accelerate and ascend faster. Period. However the penalty for adding a few hundred grams or even a kg is small and nothing that will spoil your Sunday ride. And saving a few aero watts is arguably more beneficial than saving a pound of weight, for most riding at least.
In racing and all else equal, lighter IS better. At the same power you accelerate and ascend faster. Period. However the penalty for adding a few hundred grams or even a kg is small and nothing that will spoil your Sunday ride. And saving a few aero watts is arguably more beneficial than saving a pound of weight, for most riding at least.
#39
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Why do roadies have this myopic idea that anything that doesn't make you faster isn't worth doing? Having sex with my girlfriend doesn't affect my average speed on the bike, I wouldn't call it "no gain." Light weight bikes are more fun to ride, people gain more enjoyment of the time they spend cycling, anyone who thinks that's a whole lot of nothing needs to spend some time contemplating the meaning of life. When it's coming to an end none of us will care what kind of average speeds we did, most of us will care how much joy and misery we experienced when we look back.
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#40
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Why do roadies have this myopic idea that anything that doesn't make you faster isn't worth doing? Having sex with my girlfriend doesn't affect my average speed on the bike, I wouldn't call it "no gain." Light weight bikes are more fun to ride, people gain more enjoyment of the time they spend cycling, anyone who thinks that's a whole lot of nothing needs to spend some time contemplating the meaning of life. When it's coming to an end none of us will care what kind of average speeds we did, most of us will care how much joy and misery we experienced when we look back.
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#42
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Why do roadies have this myopic idea that anything that doesn't make you faster isn't worth doing? Having sex with my girlfriend doesn't affect my average speed on the bike, I wouldn't call it "no gain." Light weight bikes are more fun to ride, people gain more enjoyment of the time they spend cycling, anyone who thinks that's a whole lot of nothing needs to spend some time contemplating the meaning of life. When it's coming to an end none of us will care what kind of average speeds we did, most of us will care how much joy and misery we experienced when we look back.
I have the most basic of bikes, a base model allez with Claris and axis sport branded wheels and I get lots of enjoyment on the bike, the only limiter is me. And I go way faster than a lot of folks because I’ve put in the work on myself. I think a lot of people buy into hype and then come up with nebulous things to justify spending way too much in absence of any tangible benefits they may have been looking for. Yeah it’s all about fun, but I think most folks have priorities outside of cycling and helping people make smart purchases is just as important as getting enjoyment.
#44
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Riding a heavier / less efficient bike has merits
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There are things called flywheels that rely on the effect of rotating weight - yes it matters
does it matter in your specific case? Probably
does it matter in your specific case? Probably
#46
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#47
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Once again GCN does stupid science.
Motorcycle world knows all too well about rotating weight, yes it matters both during acceleration and constant motion.
Reminds when GCN does "keto diet" a few years back. What a bunch of hacks.
Motorcycle world knows all too well about rotating weight, yes it matters both during acceleration and constant motion.
Reminds when GCN does "keto diet" a few years back. What a bunch of hacks.
#48
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p.s. bicycles are not motorcycles.
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#49
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#50
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