Ali v Carbon
Comments
-
Hondated wrote:Thanks everyone for your replies. I think that by asking the question I may have saved my self some money as well because it seems to me that before I buy I should improve my Bianchi ie better tyres, inflated correctly. better bar tape.And to be honest the main weight saving I need to do is to me rather than the bike.I also enjoyed reading the engineering replies and the Ali v Bianchi was after the Ali v Frazier .
Well, you're not alone in the need for yourself to be the main weight saver for the bike.
I've been at it for years now. Complete failure.0 -
-
redddraggon wrote:My Ti frame weighs 1250g, probably lighter than 50% of carbon frames.
How much new? (just frame)
winter beast: http://i497.photobucket.com/albums/rr34 ... uff016.jpg
Summer beast; http://i497.photobucket.com/albums/rr34 ... uff015.jpg0 -
-
So now a £640 carbon road frame that weighs 1250g?
Nice to have Ti but outa my pocket
winter beast: http://i497.photobucket.com/albums/rr34 ... uff016.jpg
Summer beast; http://i497.photobucket.com/albums/rr34 ... uff015.jpg0 -
redddraggon wrote:My Ti frame weighs 1250g, probably lighter than 50% of carbon frames.
Oh ya, well my Gios(steel) weighs at least twice that. 0 -
I don't think any manufacturer of carbon frames claims it is the longest lasting, toughest, unbreakable thing.
It's light. That's the beginning and end of it. For the strength and flex characteristics required to make a bike perform at it's best (read: fastest), carbon is pretty much impossible to beat these days.
You don't see manufacturer's using carbon to make touring frames much because they know there's no point. It may not last the distance, and with all that stuff on it, what use is saving a hundred grams in the frameset?
ALL carbon bikes are made with the intention of being used to race, or at least look like you are going to!!!
Side point: I was out on a training ride a few weeks back with 3 others.
Me: Pinarello Paris full carbon, Mavic Ksyrium SSC SL wheels
Other bike 1: Cervelo RS (I think) full carbon, Mavic Ksyrium Elite wheels
Other bike 2: Cannondale, the carbon/aluminium mongrel one, Mavic Ksyrium Elite wheels
Other bike 3: Bianchi, Aluminium frame, carbon fork and stays, Mavic Elite wheels.
All pretty good bikes, none of these are the budget models in the ranges. We all run tyre pressures around 110 psi, on pretty much identical wheels.
Riding over some rather bumpy roads, it was plainly obvious that the bloke getting hammered to bits was on the Bianchi. You could see the back wheel chatter over the bumps, and hear the constant rattles. By comparison, the Cervelo and me were almost silent, and the 'Dale did a pretty good job, only getting squirrely on the worst of the bumpy bits.
Even Bianchi man commented he'd have to change bikes or ride somewhere else when we mentioned it. Good, fast, light (and nice looking) frame, but a real boneshaker.
Someone here reckons it's all in the wheels, tyres and geometry, and frame material has no effect.
What cr*p.
The geometry differences between top racing frames are so small that they will have minimal impact on the actual ride characteristics. They WILL affect handling significantly.
How the bike is built and what materials are used where is 95% responsible for the ride.Open One+ BMC TE29 Seven 622SL On One Scandal Cervelo RS0 -
redddraggon wrote:My Ti frame weighs 1250g, probably lighter than 50% of carbon frames.
Don't you ride a very small frame?
Anyway http://www.canyon.com/_en/roadbikes/specs.html?b=1933 is a feck'n light Alu frame.
I'm gonna find it very hard to decide between carbon and alu when I next get a frame. That Canyon + CAAD9 + S1 are very competitors to all but the best carbon frames.0 -
Wheelspinner wrote:I don't think any manufacturer of carbon frames claims it is the longest lasting, toughest, unbreakable thing.
It's light. That's the beginning and end of it. For the strength and flex characteristics required to make a bike perform at it's best (read: fastest), carbon is pretty much impossible to beat these days.
You don't see manufacturer's using carbon to make touring frames much because they know there's no point. It may not last the distance, and with all that stuff on it, what use is saving a hundred grams in the frameset?
ALL carbon bikes are made with the intention of being used to race, or at least look like you are going to!!!
Side point: I was out on a training ride a few weeks back with 3 others.
Me: Pinarello Paris full carbon, Mavic Ksyrium SSC SL wheels
Other bike 1: Cervelo RS (I think) full carbon, Mavic Ksyrium Elite wheels
Other bike 2: Cannondale, the carbon/aluminium mongrel one, Mavic Ksyrium Elite wheels
Other bike 3: Bianchi, Aluminium frame, carbon fork and stays, Mavic Elite wheels.
All pretty good bikes, none of these are the budget models in the ranges. We all run tyre pressures around 110 psi, on pretty much identical wheels.
Riding over some rather bumpy roads, it was plainly obvious that the bloke getting hammered to bits was on the Bianchi. You could see the back wheel chatter over the bumps, and hear the constant rattles. By comparison, the Cervelo and me were almost silent, and the 'Dale did a pretty good job, only getting squirrely on the worst of the bumpy bits.
Even Bianchi man commented he'd have to change bikes or ride somewhere else when we mentioned it. Good, fast, light (and nice looking) frame, but a real boneshaker.
Someone here reckons it's all in the wheels, tyres and geometry, and frame material has no effect.
What cr*p.
The geometry differences between top racing frames are so small that they will have minimal impact on the actual ride characteristics. They WILL affect handling significantly.
How the bike is built and what materials are used where is 95% responsible for the ride.
95%... if you say so... I'll have to get myself one of these super stiff, but somehow even super compliant 950 gr carbon frames for the cobbles of the Pays du Nord and pump the tyres at 110 psi...left the forum March 20230 -
Unless you made a conscious decision to change them, you probably have 23mm tyres on your bike. Changing them to 25mm (usually the biggest that a standard road bike will allow) will make a happy and distinct difference to your riding experience. You can use slightly lower pressures (maybe 80-90psi), and the consequence will be a slightly smoother ride, and better cornering grip, for no noticeable cost to rolling resistance.Hondated wrote:Thanks everyone for your replies. I think that by asking the question I may have saved my self some money as well because it seems to me that before I buy I should improve my Bianchi ie better tyres, inflated correctly. better bar tape.And to be honest the main weight saving I need to do is to me rather than the bike.I also enjoyed reading the engineering replies and the Ali v Bianchi was after the Ali v Frazier .0 -
Far too much scare-mongering goes on around carbon, yes if you cream into the back of a car and the frame is cracked then it's a write off but then again the same is true of aluminium. Modern alloy frames are so thin walled (to compete with lighter weight carbon) than they can dent and buckle fairly easily. For example, I saw a bike the other week, Scott Speedster (alloy) I think it was, and the guy had ran straight into a parked car. The down tube had crumpled like what I can only describe as a coke can while, amazingly, the front wheel wasn't even out of true! Mavic Aksium it was - now thats what I call a tough wheel!0
-
yes. that guy has obviously never ridden carbon and noticed the vast improvement in damping out vibrations.Wheelspinner wrote:I don't think any manufacturer of carbon frames claims it is the longest lasting, toughest, unbreakable thing.
It's light. That's the beginning and end of it. For the strength and flex characteristics required to make a bike perform at it's best (read: fastest), carbon is pretty much impossible to beat these days.
You don't see manufacturer's using carbon to make touring frames much because they know there's no point. It may not last the distance, and with all that stuff on it, what use is saving a hundred grams in the frameset?
ALL carbon bikes are made with the intention of being used to race, or at least look like you are going to!!!
Side point: I was out on a training ride a few weeks back with 3 others.
Me: Pinarello Paris full carbon, Mavic Ksyrium SSC SL wheels
Other bike 1: Cervelo RS (I think) full carbon, Mavic Ksyrium Elite wheels
Other bike 2: Cannondale, the carbon/aluminium mongrel one, Mavic Ksyrium Elite wheels
Other bike 3: Bianchi, Aluminium frame, carbon fork and stays, Mavic Elite wheels.
All pretty good bikes, none of these are the budget models in the ranges. We all run tyre pressures around 110 psi, on pretty much identical wheels.
Riding over some rather bumpy roads, it was plainly obvious that the bloke getting hammered to bits was on the Bianchi. You could see the back wheel chatter over the bumps, and hear the constant rattles. By comparison, the Cervelo and me were almost silent, and the 'Dale did a pretty good job, only getting squirrely on the worst of the bumpy bits.
Even Bianchi man commented he'd have to change bikes or ride somewhere else when we mentioned it. Good, fast, light (and nice looking) frame, but a real boneshaker.
Someone here reckons it's all in the wheels, tyres and geometry, and frame material has no effect.
What cr*p.
The geometry differences between top racing frames are so small that they will have minimal impact on the actual ride characteristics. They WILL affect handling significantly.
How the bike is built and what materials are used where is 95% responsible for the ride.0 -
Wheelspinner wrote:Someone here reckons it's all in the wheels, tyres and geometry, and frame material has no effect.
What cr*p.
The geometry differences between top racing frames are so small that they will have minimal impact on the actual ride characteristics. They WILL affect handling significantly.
How the bike is built and what materials are used where is 95% responsible for the ride.
95%? Sorry, but I've just got to question that. :roll: :roll:
I'm with the guy who said "they lie".
Tires are my bet.0 -
dennisn wrote:Wheelspinner wrote:Someone here reckons it's all in the wheels, tyres and geometry, and frame material has no effect.
What cr*p.
The geometry differences between top racing frames are so small that they will have minimal impact on the actual ride characteristics. They WILL affect handling significantly.
How the bike is built and what materials are used where is 95% responsible for the ride.
95%? Sorry, but I've just got to question that. :roll: :roll:
I'm with the guy who said "they lie".
Tires are my bet.
Really? All in the tyres?
Ever ridden a TT specific frame? One you just popped your standard wheels onto, same tyres and all?
Did that ride just like your roadie?
Thought not.Open One+ BMC TE29 Seven 622SL On One Scandal Cervelo RS0 -
think about it. tyres do make a difference but the frame depends on vibrations,skocks and flexing which are all significantly different through materials with different propetys.carbon can also be formed and distributed wherever needed, not like tubes.it makes no sense that carbon can be stiff and damping but it is. if its all geometry id love an aluminium bike like it. im talking more about comfort than handling. i have no reason to lie and wasnt expecting that part when i got a carbon bike, but immediately noticed. it has its limits yes, if its impacted thats it and ill have to rebuild with an alu frame, otherwise its great exept for the sudden yield, but that should be somewhere near aluminium anyway. il steer round springy doors.dennisn wrote:Wheelspinner wrote:Someone here reckons it's all in the wheels, tyres and geometry, and frame material has no effect.
What cr*p.
The geometry differences between top racing frames are so small that they will have minimal impact on the actual ride characteristics. They WILL affect handling significantly.
How the bike is built and what materials are used where is 95% responsible for the ride.
95%? Sorry, but I've just got to question that. :roll: :roll:
I'm with the guy who said "they lie".
Tires are my bet.0 -
rake wrote:
think about it. tyres do make a difference but the frame depends on vibrations,skocks and flexing which are all significantly different through materials with different propetys.carbon can also be formed and distributed wherever needed, not like tubes.it makes no sense that carbon can be stiff and damping but it is. if its all geometry id love an aluminium bike like it. im talking more about comfort than handling. i have no reason to lie and wasnt expecting that part when i got a carbon bike, but immediately noticed. it has its limits yes, if its impacted thats it and ill have to rebuild with an alu frame, otherwise its great exept for the sudden yield, but that should be somewhere near aluminium anyway. il steer round springy doors.dennisn wrote:Wheelspinner wrote:Someone here reckons it's all in the wheels, tyres and geometry, and frame material has no effect.
What cr*p.
The geometry differences between top racing frames are so small that they will have minimal impact on the actual ride characteristics. They WILL affect handling significantly.
How the bike is built and what materials are used where is 95% responsible for the ride.
95%? Sorry, but I've just got to question that. :roll: :roll:
I'm with the guy who said "they lie".
Tires are my bet.
You said it... it does make no sense. Stiffness and resilience cannot be proportional... it's maths... you can't fight maths with subjective perceptions.
It's placebo... but if it works... then it's worth spending money for carbon... I don't believe it, so it doesn't work for me.
All materials will fracture upon impact, it's the way they do it which discriminate... do they absorb part of the energy or not? That matters for your health... carbon doesn't , be warned!left the forum March 20230 -
i was pre warned and its a worry. but how could a placebo work if i wasnt aware to begin with. i wouldnt be looking. also ive walked about labouring for 12 hours with a broken big toe in the past, so the placebo hypochondriac idea is well and truely redundant on me, i tend to be stupid the other way and not seek help when i should. i dont think the simple maths are so here with vibration transmissions etc, liike a shock absorber you can have a harder spring with a lower spring rate, and a softer spring with a higher spring rate. carbon could have a lower preload than metal but stiffen up faster. its not just stress against strain.most bikes have carbon forks anyway so its hard to escape it.0
-
ugo.santalucia wrote:rake wrote:
think about it. tyres do make a difference but the frame depends on vibrations,skocks and flexing which are all significantly different through materials with different propetys.carbon can also be formed and distributed wherever needed, not like tubes.it makes no sense that carbon can be stiff and damping but it is. if its all geometry id love an aluminium bike like it. im talking more about comfort than handling. i have no reason to lie and wasnt expecting that part when i got a carbon bike, but immediately noticed. it has its limits yes, if its impacted thats it and ill have to rebuild with an alu frame, otherwise its great exept for the sudden yield, but that should be somewhere near aluminium anyway. il steer round springy doors.dennisn wrote:Wheelspinner wrote:Someone here reckons it's all in the wheels, tyres and geometry, and frame material has no effect.
What cr*p.
The geometry differences between top racing frames are so small that they will have minimal impact on the actual ride characteristics. They WILL affect handling significantly.
How the bike is built and what materials are used where is 95% responsible for the ride.
95%? Sorry, but I've just got to question that. :roll: :roll:
I'm with the guy who said "they lie".
Tires are my bet.
You said it... it does make no sense. Stiffness and resilience cannot be proportional... it's maths... you can't fight maths with subjective perceptions.
It's placebo... but if it works... then it's worth spending money for carbon... I don't believe it, so it doesn't work for me.
All materials will fracture upon impact, it's the way they do it which discriminate... do they absorb part of the energy or not? That matters for your health... carbon doesn't , be warned!
Oh my giddy freakin' aunt....
To the OP, ignore this numbskull, who has quite probably never ridden a bicycle manufactured in the last 30 years.
This is the type of person who will insist there is absolutely no discernible difference between a vintage Dom Perignon champagne and a 3 quid Asti from your local bottle shop, because on the label they both have the same alcohol content. It's the maths, see? That's the important measurement, isn't it?
He'll also tell you an amplifier you buy from your local Radio Shack in kit form and assemble yourself sounds exactly like a Krell, or Halcro, or Levinson because the maths tells him the THD and power output are the same on the test bench. Maths are never wrong are they? The amplifiers must sound identical because he measured the same results from them all.
Oh, and a bespoke suit from Saville Row can;t possibly be any better than an off the rack from Target, because they are both made from the same basic material: wool. Gee, using two yards of fabric to start with could not POSSIBLY end up with a different end product if made by two different people could it???
And apparently, the ONLY thing to consider when you are investing your hard-earned in a new bike is what will happen if you crash it. Wow, isn't that a positive attitude?Open One+ BMC TE29 Seven 622SL On One Scandal Cervelo RS0 -
Wheelspinner wrote:ugo.santalucia wrote:rake wrote:
think about it. tyres do make a difference but the frame depends on vibrations,skocks and flexing which are all significantly different through materials with different propetys.carbon can also be formed and distributed wherever needed, not like tubes.it makes no sense that carbon can be stiff and damping but it is. if its all geometry id love an aluminium bike like it. im talking more about comfort than handling. i have no reason to lie and wasnt expecting that part when i got a carbon bike, but immediately noticed. it has its limits yes, if its impacted thats it and ill have to rebuild with an alu frame, otherwise its great exept for the sudden yield, but that should be somewhere near aluminium anyway. il steer round springy doors.dennisn wrote:Wheelspinner wrote:Someone here reckons it's all in the wheels, tyres and geometry, and frame material has no effect.
What cr*p.
The geometry differences between top racing frames are so small that they will have minimal impact on the actual ride characteristics. They WILL affect handling significantly.
How the bike is built and what materials are used where is 95% responsible for the ride.
95%? Sorry, but I've just got to question that. :roll: :roll:
I'm with the guy who said "they lie".
Tires are my bet.
You said it... it does make no sense. Stiffness and resilience cannot be proportional... it's maths... you can't fight maths with subjective perceptions.
It's placebo... but if it works... then it's worth spending money for carbon... I don't believe it, so it doesn't work for me.
All materials will fracture upon impact, it's the way they do it which discriminate... do they absorb part of the energy or not? That matters for your health... carbon doesn't , be warned!
Oh my giddy freakin' aunt....
To the OP, ignore this numbskull, who has quite probably never ridden a bicycle manufactured in the last 30 years.
This is the type of person who will insist there is absolutely no discernible difference between a vintage Dom Perignon champagne and a 3 quid Asti from your local bottle shop, because on the label they both have the same alcohol content. It's the maths, see? That's the important measurement, isn't it?
He'll also tell you an amplifier you buy from your local Radio Shack in kit form and assemble yourself sounds exactly like a Krell, or Halcro, or Levinson because the maths tells him the THD and power output are the same on the test bench. Maths are never wrong are they? The amplifiers must sound identical because he measured the same results from them all.
Oh, and a bespoke suit from Saville Row can;t possibly be any better than an off the rack from Target, because they are both made from the same basic material: wool. Gee, using two yards of fabric to start with could not POSSIBLY end up with a different end product if made by two different people could it???
And apparently, the ONLY thing to consider when you are investing your hard-earned in a new bike is what will happen if you crash it. Wow, isn't that a positive attitude?
There is a huge difference between a Champagne and an Asti spumante. The latter is made with a "Charmat" method, partial fermentation, leading to a sweet product with low alcohol... about 6-8%. The former is made with a Champenoise method, leading to a dry product with a higher % of alcohol (so you are wrong in this as well). Of course one could also argue that the type of grapes are different, but that is less relevant... infact the difference between a Champagne and a Cava, made with different grapes but with the same method is a lot more subtle...
Infact it's a bit like tyres vs frame... where the method is the tyre and the grapes are the frame... the latter is irrelevant when compared to the former.
Trust me, I come from Piemonte, the Asti spumante producing region... left the forum March 20230 -
Hondated wrote:Ali v Bianchi was after the Ali v Frazier .
The Tumble in Treviglio?Neil
Help I'm Being Oppressed0 -
rake wrote:i was pre warned and its a worry. but how could a placebo work if i wasnt aware to begin with. i wouldnt be looking. also ive walked about labouring for 12 hours with a broken big toe in the past, so the placebo hypochondriac idea is well and truely redundant on me, i tend to be stupid the other way and not seek help when i should. i dont think the simple maths are so here with vibration transmissions etc, liike a shock absorber you can have a harder spring with a lower spring rate, and a softer spring with a higher spring rate. carbon could have a lower preload than metal but stiffen up faster. its not just stress against strain.most bikes have carbon forks anyway so its hard to escape it.
Well, the idea is that everybody say one thing and you start to experience it as well... it's kind of placebo. Also, carbon sounds different, you hit a hole and it doesn't make the same noise as metals, that can give you the impression of more spring...
But reality is that it cannot absorb compression stresses, so there is no way it can damp vibrations.
A rubber tube filled with gas can do that and will do that. Riding at 130 psi or 90 psi makes a huge difference. Other sources of damping can be padded bar tape or gel, saddles with a bit of padding... the chamois in your bibshorts... your gloves... the sole of your shoes... ultimately your joints...
All of them damp vibrations a lot better than a set of stiff tubes... so I don't see how the set of tubes can have such a big relevance, if not in your mind...left the forum March 20230 -
rake wrote:i was pre warned and its a worry. but how could a placebo work if i wasnt aware to begin with. i wouldnt be looking. also ive walked about labouring for 12 hours with a broken big toe in the past, so the placebo hypochondriac idea is well and truely redundant on me, i tend to be stupid the other way and not seek help when i should. i dont think the simple maths are so here with vibration transmissions etc, liike a shock absorber you can have a harder spring with a lower spring rate, and a softer spring with a higher spring rate. carbon could have a lower preload than metal but stiffen up faster. its not just stress against strain.most bikes have carbon forks anyway so its hard to escape it.
These considerations are doubtlessly very relevant if the matter at hand is, say, the harmonics of a musical instrument. All materials have a harmonic response that varies in many interesting ways. A bicycle frame, however, is practically rigid in the vertical plane: any distortion is off the bottom of the scale for detectable cushioning effect. Moreover, the assembly is rubber mounted on pressurised air buffers at one side, and by flexible plastic and foam on the other.
To exempt yourself from the placebo effect is over-confident. The methodology of blinded testing procedure, which underpins much practical scientific development, assumes that we are hopelessly led by our expectations and prejudices. In this case, I think our judgemental bias is aided by the aural differences between bike frames: they ring to different sounds. Consider how many noises your bike transmits to you.
edit: we seem to have posted the same thing at the same time...0 -
balthazar wrote:rake wrote:i was pre warned and its a worry. but how could a placebo work if i wasnt aware to begin with. i wouldnt be looking. also ive walked about labouring for 12 hours with a broken big toe in the past, so the placebo hypochondriac idea is well and truely redundant on me, i tend to be stupid the other way and not seek help when i should. i dont think the simple maths are so here with vibration transmissions etc, liike a shock absorber you can have a harder spring with a lower spring rate, and a softer spring with a higher spring rate. carbon could have a lower preload than metal but stiffen up faster. its not just stress against strain.most bikes have carbon forks anyway so its hard to escape it.
These considerations are doubtlessly very relevant if the matter at hand is, say, the harmonics of a musical instrument. All materials have a harmonic response that varies in many interesting ways. A bicycle frame, however, is practically rigid in the vertical plane: any distortion is off the bottom of the scale for detectable cushioning effect. Moreover, the assembly is rubber mounted on pressurised air buffers at one side, and by flexible plastic and foam on the other.
To exempt yourself from the placebo effect is over-confident. The methodology of blinded testing procudures, which underpin much practical scientific development, assumes that we are hopelessly led by our expectations and prejudices. In this case, I think our judgemental bias is aided by the aural differences between bike frames: they ring to different sounds. Consider how many noises your bike transmits to you.
edit: we seem to have posted the same thing at the same time...
Hey, we wrote the same thing at the same time... just you wrote it better ! left the forum March 20230 -
I'd say get some test rides of different bikes and then you can see if it is worth changing. for example I have ridden a Scot CR 1 which was stif and quite harsh over bumps (Carbon), also a specialised tarmac (Carbon) that had a smooth character, but the fork felt too flexy to me, and a Carbon Pearson which was between the two. I have a titanium enigma esprit which feels stiffer (and transmits a bit more road feel) than the Pearson used to.
Most componants can make a difference - I have a few sets of wheels and the most omfy are the 32 spoke handbuilts with double butted spokes. Comic Carbon deep section are good, kyserium SSCs feel harsh in comparison.
Add in the aded factor of different tyres and tubes and there is another variable. I used ot use Michelin pro race IIs but vitoria open evo CX (the older ones) appear much more comfortable - this is increased by using the 25c version and / or using latex tubes.
Finally tyre pressure makes a difference too.
I think if your alloy frame fits you well then try a set of (borrowed if neccessary) handbuilt wheels with 25c tyres, latex tubes at a lower pressure and then go from there. It is cheaper than a new bike!0 -
for a start when i first rode a carbon bike summer 2009 i didnt know much about carbon and had never heard anything about ride quality so i dont know how i could just be towing the line. also you idiot compression isnt the only force acting on a bike frame so your observation about compression is redundant. my aluminium bike rattles the handlebars like hell, the carbon one doesnt, and idiot could notice.they both have 23mm tyres at similar pressures on the same roads with the same rider at the same speeds so whats causing the dirrerence. i dont exempt myself from influences as you say, but your not laying your placebo crap/ on me.0
-
There's definitely something funny about your wheels...alan sherman wrote:Comic Carbon deep section are good
More seriously, it's worth pointing out that placebo effects can go both ways, i.e. it's possible to discount a real difference because you don't believe it's there.
It would be interesting but tricky to try blind trials of different frames (wrap them in layers of bubble wrap to hide the frame and deaden sounds?), for that matter you could add tyres etc. into the mix.
I seem to remember last time there was a thread like this the debate was whether you could tell the difference between cheap and expensive carbon frames; I still reckon the probable answer is "not much" but that's a hunch based on my prejudices, yours are probably different.
ugo.s, a lot of what you say seems to make sense to me, but I'm not sure about all these exploding carbon frames you mention, what kind of failure rates are we talking about here? Under what circumstances?0 -
I can visualise an arrangement wherein a bike is placed on a textured rolling road, with a blindfolded and ear-defender'd rider (literally blinded!); freewheeling to ignore pedalling effects, and consequent lateral frame flex. With appropriate equipment, distortion could be recorded at various points of the frame. I dimly remember some university or other setting this up once, but I can't remember where, or even if I imagined it.bompington wrote:It would be interesting but tricky to try blind trials of different frames (wrap them in layers of bubble wrap to hide the frame and deaden sounds?), for that matter you could add tyres etc. into the mix.0 -
bompington wrote:
There's definitely something funny about your wheels...alan sherman wrote:Comic Carbon deep section are good
More seriously, it's worth pointing out that placebo effects can go both ways, i.e. it's possible to discount a real difference because you don't believe it's there.
It would be interesting but tricky to try blind trials of different frames (wrap them in layers of bubble wrap to hide the frame and deaden sounds?), for that matter you could add tyres etc. into the mix.
I seem to remember last time there was a thread like this the debate was whether you could tell the difference between cheap and expensive carbon frames; I still reckon the probable answer is "not much" but that's a hunch based on my prejudices, yours are probably different.
ugo.s, a lot of what you say seems to make sense to me, but I'm not sure about all these exploding carbon frames you mention, what kind of failure rates are we talking about here? Under what circumstances?
Well, I don't have figures in terms of failures per unit sold... but the perception is that they are much higher than for other materials. Reason is due to the limited amount of material used, the defects tolerance is extremely low.
What I know for sure and this is science, is that a fibre composite does absorb very little energy in an impact, the result being more dangerous. A metal alloy will bend before fracturing, hence slwonig down a fall, for example... a CFC won't, it'll just snap.
Also, if you are careful, you can observe a crack developing in a metal alloy and replace the frame before it sends you to the hospital. That's a lot less likely in a CFC which won't warn you before failing.
So I'm talking about two different things:
1) they fail more frequently and without need of ageing (so it's not fatigue) and I guess that's a manufacturing issue
2) When they fail, they do so catastrophically and with no warning.
The stiffness/compliance issue is purely academic... I'm talking by the numbers, others talk by their personal experience... some add insults here and there because they've got little else to say. My feeling is that is all placebo, that shouldn't offend anyone and whoever feels their carbon bike is more comfty, he's got all the rights to keep thinking so.
As I said earlier, there is the need of a regulator in the industry, especially for the safety issue. I can't believe 900 grams frames which fall apart just by going over a shallow pothole can go on the market without proper independent testing... especially considering they cost up to 3K pounds.left the forum March 20230
