Trend towards heavier more aero frames?
07-08-20, 11:46 PM
#26
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Why does more heavy equal more aero? Maybe they are just more heavy, because whatever, cost, ease of production, who knows. Why is aero necessarily heavy?
Mind you, you are specifically talking about frames, so no the fact that disc brakes may add weight, or larger tires may be heavier or something like that, but just the frame itself.
Mind you, you are specifically talking about frames, so no the fact that disc brakes may add weight, or larger tires may be heavier or something like that, but just the frame itself.
07-09-20, 12:11 AM
#27
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Heavy doesn't necessarily imply aero, but...
...emphasizing aerodynamic performance generally does increase weight. The simple reason for this is that the shape that is structurally optimal for a given purpose, and the shape that offers the best aerodynamic performance, are usually two very different shapes. Giving something a more aerodynamically-optimal shape means that it's typically less well-optimized in terms of strength-to-weight ratio, so if you still want it to be adequately strong, it'll end up heavier than something that wasn't concerned with aerodynamics.
Disc brakes do typically result in a heavier frameset, it's not just the weight of the brakes and rotors themselves. Disc brake rotors have much lower diameter than bicycle rims, which means they have much less leverage over the wheel. The means that the brake needs to put much higher force on the rotor than a rim brake puts on the rim. Thanks to Newton's Third Law of Motion, this also means that the rotor puts a much higher force on the brake (and the spot on the frame where it's mounted) than a rim puts on a rim brake. So disc-brake frames need to be very strong and stiff in the areas that the brakes are mounted.
Why is aero necessarily heavy?
Mind you, you are specifically talking about frames, so no the fact that disc brakes may add weight, or larger tires may be heavier or something like that, but just the frame itself.
07-09-20, 05:16 AM
#28
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Heavy doesn't necessarily imply aero, but...
...emphasizing aerodynamic performance generally does increase weight. The simple reason for this is that the shape that is structurally optimal for a given purpose, and the shape that offers the best aerodynamic performance, are usually two very different shapes. Giving something a more aerodynamically-optimal shape means that it's typically less well-optimized in terms of strength-to-weight ratio, so if you still want it to be adequately strong, it'll end up heavier than something that wasn't concerned with aerodynamics.
Disc brakes do typically result in a heavier frameset, it's not just the weight of the brakes and rotors themselves. Disc brake rotors have much lower diameter than bicycle rims, which means they have much less leverage over the wheel. The means that the brake needs to put much higher force on the rotor than a rim brake puts on the rim. Thanks to Newton's Third Law of Motion, this also means that the rotor puts a much higher force on the brake (and the spot on the frame where it's mounted) than a rim puts on a rim brake. So disc-brake frames need to be very strong and stiff in the areas that the brakes are mounted.
...emphasizing aerodynamic performance generally does increase weight. The simple reason for this is that the shape that is structurally optimal for a given purpose, and the shape that offers the best aerodynamic performance, are usually two very different shapes. Giving something a more aerodynamically-optimal shape means that it's typically less well-optimized in terms of strength-to-weight ratio, so if you still want it to be adequately strong, it'll end up heavier than something that wasn't concerned with aerodynamics.
Disc brakes do typically result in a heavier frameset, it's not just the weight of the brakes and rotors themselves. Disc brake rotors have much lower diameter than bicycle rims, which means they have much less leverage over the wheel. The means that the brake needs to put much higher force on the rotor than a rim brake puts on the rim. Thanks to Newton's Third Law of Motion, this also means that the rotor puts a much higher force on the brake (and the spot on the frame where it's mounted) than a rim puts on a rim brake. So disc-brake frames need to be very strong and stiff in the areas that the brakes are mounted.
07-09-20, 06:50 AM
#29
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Moderate aero can look cool but aero + discs = vugly
07-09-20, 06:54 AM
#30
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07-09-20, 07:02 AM
#31
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Great questions. As someone who has owned and ridden all three generations of Domane frames, seen the weight from the first to the latest gain a pound, and gone from stuffing 32mm tires on the first for grins to 40mm gravel tires as an adventure set of wheels on the current, all I can say is the current one goes more places and is more fun to ride. I would add in faster, adjusted for the fact that my 63 year old legs are not quite what they were 7 years ago.
I have, however, been doing a little "weight weenie" mods to the bike to lighten it up a little, but it's likely that these very expensive modifications aren't really doing much but pleasing my ego while destroying my wallet
