|
|
Thread Tools | Display Modes |
#31
|
|||
|
|||
To carbon fork or not to carbon fork...
On Oct 17, 5:43*pm, AMuzi wrote:
On 10/17/2012 10:56 AM, Duane Hébert wrote: On 10/17/2012 10:17 AM, landotter wrote: On Oct 13, 9:05 pm, piscesboy wrote: I'm considering getting a road bike and considering whether to get the "standard" model or the same model with a carbon fork for $100 or so more. It's supposed to make for a more stable ride on rougher roads, but what are your conclusions/reviews/recommendations on this claim? Did the bike shop make this claim? Because it's bull****. Get a carbon fork if it comes with a bike you like, or if you're racing and it'll help you drop some grams. Otherwise, it doesn't matter. For comfort, large tires and cockpit details are far more important. You don't think that a carbon fork would be more comfortable than an aluminum fork on the same frame with 125 psi 700 x 23c tires? I don't. They are probably both adequately strong and of the same geometry as far as handling but I bet you could not tell them apart if similarly painted. I agree with Andrew. While I don't own a carbon fork bike, I've ridden several of my friends' carbon bikes. I don't think carbon has any magic effect on comfort, and AFAIK neither do the friends who bought those bikes. The first couple of guys to buy carbon seem to have done it before claims of magic comfort came out - at least, I don't recall such claims in the 1990s - and they never mentioned any such comfort. One woman even bought a Zertz-equipped carbon bike a few years ago, and she specifically said she couldn't tell any comfort difference between her steel bikes. But to get technical, as we do here from time to time: What would cause the difference? As far as I know, once fit is dialed in, the main "comfort" effect (i.e. reduction in road shock) comes from flexibility in the vertical direction. There's no way a typical carbon fork flexes significantly more in the vertical than a typical steel or aluminum fork. Any difference is far, far smaller than the deflection of the tire. There might be a small effect from the reduction in fork mass that comes from using carbon fiber. That is, once the fork mass has been accelerated upward by a bump, a massier fork will transmit more force to the rider's hands than a fork with less mass. But the mass of the fork is a small percentage of the total mass being moved upward, so any difference due directly to fork mass reduction should be small, I think. And it occurs to me, the smoothest riding cars and motorcycles tend to have larger sprung masses and smaller unsprung masses; for smooth ride, it's considered more beneficial to reduce the upward motion of the sprung mass, rather than to lessen that mass and thus allow more upward motion. (We could discuss this, I suppose.) In any case, I think the claims for carbon forks put us back into "The princess and the pea" territory. You want comfort? Fit a fatter tire - if your fork will allow it, that is. A great many carbon forks won't allow fatter tires. Today's weird fashion is carbon plus near-zero tire clearance. And there's no accounting for fashion. Or for its sales pitches. - Frank Krygowski |
Ads |
#32
|
|||
|
|||
To carbon fork or not to carbon fork...
On 10/17/2012 8:38 PM, Frank Krygowski wrote:
On Oct 17, 5:43 pm, AMuzi wrote: On 10/17/2012 10:56 AM, Duane Hébert wrote: On 10/17/2012 10:17 AM, landotter wrote: On Oct 13, 9:05 pm, piscesboy wrote: I'm considering getting a road bike and considering whether to get the "standard" model or the same model with a carbon fork for $100 or so more. It's supposed to make for a more stable ride on rougher roads, but what are your conclusions/reviews/recommendations on this claim? Did the bike shop make this claim? Because it's bull****. Get a carbon fork if it comes with a bike you like, or if you're racing and it'll help you drop some grams. Otherwise, it doesn't matter. For comfort, large tires and cockpit details are far more important. You don't think that a carbon fork would be more comfortable than an aluminum fork on the same frame with 125 psi 700 x 23c tires? I don't. They are probably both adequately strong and of the same geometry as far as handling but I bet you could not tell them apart if similarly painted. I agree with Andrew. While I don't own a carbon fork bike, I've ridden several of my friends' carbon bikes. I don't think carbon has any magic effect on comfort, and AFAIK neither do the friends who bought those bikes. The first couple of guys to buy carbon seem to have done it before claims of magic comfort came out - at least, I don't recall such claims in the 1990s - and they never mentioned any such comfort. One woman even bought a Zertz-equipped carbon bike a few years ago, and she specifically said she couldn't tell any comfort difference between her steel bikes. But to get technical, as we do here from time to time: What would cause the difference? As far as I know, once fit is dialed in, the main "comfort" effect (i.e. reduction in road shock) comes from flexibility in the vertical direction. There's no way a typical carbon fork flexes significantly more in the vertical than a typical steel or aluminum fork. Any difference is far, far smaller than the deflection of the tire. There might be a small effect from the reduction in fork mass that comes from using carbon fiber. That is, once the fork mass has been accelerated upward by a bump, a massier fork will transmit more force to the rider's hands than a fork with less mass. But the mass of the fork is a small percentage of the total mass being moved upward, so any difference due directly to fork mass reduction should be small, I think. And it occurs to me, the smoothest riding cars and motorcycles tend to have larger sprung masses and smaller unsprung masses; for smooth ride, it's considered more beneficial to reduce the upward motion of the sprung mass, rather than to lessen that mass and thus allow more upward motion. (We could discuss this, I suppose.) In any case, I think the claims for carbon forks put us back into "The princess and the pea" territory. You want comfort? Fit a fatter tire - if your fork will allow it, that is. A great many carbon forks won't allow fatter tires. Today's weird fashion is carbon plus near-zero tire clearance. And there's no accounting for fashion. Or for its sales pitches. - Frank Krygowski I recently did a floor pump rebuild. Customer wanted assurance that he could get his preferred 130psi from it so I did just that on my own front wheel, which was nearby. I sure did notice that running errands an hour later! -- Andrew Muzi www.yellowjersey.org/ Open every day since 1 April, 1971 |
#33
|
|||
|
|||
To carbon fork or not to carbon fork...
On Thursday, October 18, 2012 12:38:13 PM UTC+11, Frank Krygowski wrote:
On Oct 17, 5:43*pm, AMuzi wrote: On 10/17/2012 10:56 AM, Duane Hébert wrote: On 10/17/2012 10:17 AM, landotter wrote: On Oct 13, 9:05 pm, piscesboy wrote: I'm considering getting a road bike and considering whether to get the "standard" model or the same model with a carbon fork for $100 or so more. It's supposed to make for a more stable ride on rougher roads, but what are your conclusions/reviews/recommendations on this claim? Did the bike shop make this claim? Because it's bull****. Get a carbon fork if it comes with a bike you like, or if you're racing and it'll help you drop some grams. Otherwise, it doesn't matter. For comfort, large tires and cockpit details are far more important. You don't think that a carbon fork would be more comfortable than an aluminum fork on the same frame with 125 psi 700 x 23c tires? I don't. They are probably both adequately strong and of the same geometry as far as handling but I bet you could not tell them apart if similarly painted. I agree with Andrew. While I don't own a carbon fork bike, I've ridden several of my friends' carbon bikes. I don't think carbon has any magic effect on comfort, and AFAIK neither do the friends who bought those bikes. The first couple of guys to buy carbon seem to have done it before claims of magic comfort came out - at least, I don't recall such claims in the 1990s - and they never mentioned any such comfort. One woman even bought a Zertz-equipped carbon bike a few years ago, and she specifically said she couldn't tell any comfort difference between her steel bikes. I do not disbelieve those who complained about earlier all Al frames being harsh. They had a bicycle (or more likely several bicycles) before their Al bike, and consequently had something to compare too. It was because of these complaints that manufacturers have taken measures to improve comfort. Not all Al bikes are (were) harsh though, and certainly steel and CRFP can be made to be every bit as harsh or more if you want. Wheel design can also have some effect on perceived comfort. A mate and I swapped bikes while warming up before a race not long ago. We both concluded that my steel frame felt stiffer than his Ti frame, though they are about the same size, have a CFRP fork, oversize tubes, hard saddle - and even though his wheels are (presumably) very rigid Zipp 404s. When we swapped back, he mentioned it first, but I was already thinking it. Materials can make perceivable differences in feel - even when outside dimensions look quite similar. Of course, my steel frame weighs about 500 g more and cost less than half as much ;-) But to get technical, as we do here from time to time: What would cause the difference? As far as I know, once fit is dialed in, the main "comfort" effect (i.e. reduction in road shock) comes from flexibility in the vertical direction. There's no way a typical carbon fork flexes significantly more in the vertical than a typical steel or aluminum fork. Any difference is far, far smaller than the deflection of the tire. There might be a small effect from the reduction in fork mass that comes from using carbon fiber. That is, once the fork mass has been accelerated upward by a bump, a massier fork will transmit more force to the rider's hands than a fork with less mass. But the mass of the "Massier"? What was wrong with heavier, or "a fork with more mass"? fork is a small percentage of the total mass being moved upward, so any difference due directly to fork mass reduction should be small, I think. And it occurs to me, the smoothest riding cars and motorcycles tend to have larger sprung masses and smaller unsprung masses; for smooth ride, it's considered more beneficial to reduce the upward motion of the sprung mass, rather than to lessen that mass and thus allow more upward motion. (We could discuss this, I suppose.) I guess one question is where do you consider the spring? A 23 mm tyre at 125 psi with little load on it doesn't deflect much. Perhaps the spring is in the wrists and arms. Having a lighter front end is easier for these "suspension components" to absorb the movement and shock.. One other thing is that some of the movement in a fork as you ride over bumps is backward and forward (rather than up and down). This may contribute to the road "buzz" you feel. CFRP will possibly damp that buzz more than metal. In any case, I think the claims for carbon forks put us back into "The princess and the pea" territory. You want comfort? Fit a fatter tire - if your fork will allow it, that is. A great many carbon forks won't allow fatter tires. OTOH, if you look it is not so difficult to find CFRP forks that do have adequate tyre clearance and eyelets for mudguards. A quick search yields... http://www.ribblecycles.co.uk/sp/roa...es/DEDAFORW200 http://www.kinesisbikes.co.uk/products/forks/road/dc07 http://www.kinesisbikes.co.uk/products/forks/road/dc21 The cyclocross world offers more range. -- JS |
#34
|
|||
|
|||
To carbon fork or not to carbon fork...
On 10/17/2012 08:32 PM, John B. wrote:
On Wed, 17 Oct 2012 11:56:11 -0400, Duane Hébert wrote: On 10/17/2012 10:17 AM, landotter wrote: On Oct 13, 9:05 pm, piscesboy wrote: I'm considering getting a road bike and considering whether to get the "standard" model or the same model with a carbon fork for $100 or so more. It's supposed to make for a more stable ride on rougher roads, but what are your conclusions/reviews/recommendations on this claim? Did the bike shop make this claim? Because it's bull****. Get a carbon fork if it comes with a bike you like, or if you're racing and it'll help you drop some grams. Otherwise, it doesn't matter. For comfort, large tires and cockpit details are far more important. You don't think that a carbon fork would be more comfortable than an aluminum fork on the same frame with 125 psi 700 x 23c tires? I can't say for the aluminum but certainly my Giant TCR2 with a carbon fork and 300C 23 tires (or smaller) didn't feel any different, at least nothing that could be attributed to the fork, then a light steel bike road bike with the usual curved steel fork. So if there is a difference it is not memorable enough that one can notice it riding the same route on different days. I'm not saying that there is a difference. Only that most of the bike shops seem to be saying that. |
#35
|
|||
|
|||
To carbon fork or not to carbon fork...
On Wednesday, October 17, 2012 9:54:15 PM UTC-4, AMuzi wrote:
On 10/17/2012 8:38 PM, Frank Krygowski wrote: On Oct 17, 5:43 pm, AMuzi wrote: On 10/17/2012 10:56 AM, Duane H�bert wrote: On 10/17/2012 10:17 AM, landotter wrote: On Oct 13, 9:05 pm, piscesboy wrote: I'm considering getting a road bike and considering whether to get the "standard" model or the same model with a carbon fork for $100 or so more. It's supposed to make for a more stable ride on rougher roads, but what are your conclusions/reviews/recommendations on this claim? Did the bike shop make this claim? Because it's bull****. Get a carbon fork if it comes with a bike you like, or if you're racing and it'll help you drop some grams. Otherwise, it doesn't matter. For comfort, large tires and cockpit details are far more important. You don't think that a carbon fork would be more comfortable than an aluminum fork on the same frame with 125 psi 700 x 23c tires? I don't. They are probably both adequately strong and of the same geometry as far as handling but I bet you could not tell them apart if similarly painted. I agree with Andrew. While I don't own a carbon fork bike, I've ridden several of my friends' carbon bikes. I don't think carbon has any magic effect on comfort, and AFAIK neither do the friends who bought those bikes. The first couple of guys to buy carbon seem to have done it before claims of magic comfort came out - at least, I don't recall such claims in the 1990s - and they never mentioned any such comfort. One woman even bought a Zertz-equipped carbon bike a few years ago, and she specifically said she couldn't tell any comfort difference between her steel bikes. But to get technical, as we do here from time to time: What would cause the difference? As far as I know, once fit is dialed in, the main "comfort" effect (i.e. reduction in road shock) comes from flexibility in the vertical direction. There's no way a typical carbon fork flexes significantly more in the vertical than a typical steel or aluminum fork. Any difference is far, far smaller than the deflection of the tire. There might be a small effect from the reduction in fork mass that comes from using carbon fiber. That is, once the fork mass has been accelerated upward by a bump, a massier fork will transmit more force to the rider's hands than a fork with less mass. But the mass of the fork is a small percentage of the total mass being moved upward, so any difference due directly to fork mass reduction should be small, I think. And it occurs to me, the smoothest riding cars and motorcycles tend to have larger sprung masses and smaller unsprung masses; for smooth ride, it's considered more beneficial to reduce the upward motion of the sprung mass, rather than to lessen that mass and thus allow more upward motion. (We could discuss this, I suppose.) In any case, I think the claims for carbon forks put us back into "The princess and the pea" territory. You want comfort? Fit a fatter tire - if your fork will allow it, that is. A great many carbon forks won't allow fatter tires. Today's weird fashion is carbon plus near-zero tire clearance. And there's no accounting for fashion. Or for its sales pitches. - Frank Krygowski I recently did a floor pump rebuild. Customer wanted assurance that he could get his preferred 130psi from it so I did just that on my own front wheel, which was nearby. I sure did notice that running errands an hour later! I'm not surprised. The difference in vertical deflection of a tire varies a _lot_ with tire pressure. The 3 speed bike I built last year gets used only for short utility rides, seldom more than five miles. It's got 32mm tires on it, and I don't bother to pump them until they get quite soft, like 50 psi. The cushy low pressure ride is kind of nice, but then I get worried about pinch flats. 130 psi would rattle out my tooth fillings, if the tires didn't blow off first. - Frank Krygowski |
#36
|
|||
|
|||
To carbon fork or not to carbon fork...
On Wednesday, October 17, 2012 10:37:52 PM UTC-4, James wrote:
On Thursday, October 18, 2012 12:38:13 PM UTC+11, Frank Krygowski wrote: There might be a small effect from the reduction in fork mass that comes from using carbon fiber. That is, once the fork mass has been accelerated upward by a bump, a massier fork will transmit more force to the rider's hands than a fork with less mass. But the mass of the "Massier"? What was wrong with heavier, or "a fork with more mass"? Well, there's the extra typing (although that's moot if someone complains). There's also the fact that "heavier" implies more weight, but strictly speaking it's the mass, not the weight, that's responsible for the effect I was describing. I spent many years teaching engineering mechanics & physics, so I tend to pay attention to the difference., fork is a small percentage of the total mass being moved upward, so any difference due directly to fork mass reduction should be small, I think. And it occurs to me, the smoothest riding cars and motorcycles tend to have larger sprung masses and smaller unsprung masses; for smooth ride, it's considered more beneficial to reduce the upward motion of the sprung mass, rather than to lessen that mass and thus allow more upward motion. (We could discuss this, I suppose.) I guess one question is where do you consider the spring? A 23 mm tyre at 125 psi with little load on it doesn't deflect much. True! That's why they're the first thing to change for rough road use. Perhaps the spring is in the wrists and arms. Having a lighter front end is easier for these "suspension components" to absorb the movement and shock. If you're after comfort (in the sense of less perceived shock) I think you want to stop the shock _before_ it gets to your wrists and arms. One other thing is that some of the movement in a fork as you ride over bumps is backward and forward (rather than up and down). This may contribute to the road "buzz" you feel. CFRP will possibly damp that buzz more than metal. In any case, I think the claims for carbon forks put us back into "The princess and the pea" territory. You want comfort? Fit a fatter tire - if your fork will allow it, that is. A great many carbon forks won't allow fatter tires. OTOH, if you look it is not so difficult to find CFRP forks that do have adequate tyre clearance and eyelets for mudguards. A quick search yields.... http://www.ribblecycles.co.uk/sp/roa...es/DEDAFORW200 http://www.kinesisbikes.co.uk/products/forks/road/dc07 http://www.kinesisbikes.co.uk/products/forks/road/dc21 The cyclocross world offers more range. It's good there are some out there. It would be better if there were more, and if they all specified enough dimensions so one could be sure what would fit. - Frank Krygowski |
#37
|
|||
|
|||
To carbon fork or not to carbon fork...
On Oct 18, 4:44*pm, wrote:
On Wednesday, October 17, 2012 9:54:15 PM UTC-4, AMuzi wrote: On 10/17/2012 8:38 PM, Frank Krygowski wrote: On Oct 17, 5:43 pm, AMuzi wrote: On 10/17/2012 10:56 AM, Duane H bert wrote: On 10/17/2012 10:17 AM, landotter wrote: On Oct 13, 9:05 pm, piscesboy wrote: I'm considering getting a road bike and considering whether to get the "standard" model or the same model with a carbon fork for $100 or so more. It's supposed to make for a more stable ride on rougher roads, but what are your conclusions/reviews/recommendations on this claim? Did the bike shop make this claim? Because it's bull****. Get a carbon fork if it comes with a bike you like, or if you're racing and it'll help you drop some grams. Otherwise, it doesn't matter. For comfort, large tires and cockpit details are far more important. You don't think that a carbon fork would be more comfortable than an aluminum fork on the same frame with 125 psi 700 x 23c tires? I don't. They are probably both adequately strong and of the same geometry as far as handling but I bet you could not tell them apart if similarly painted. I agree with Andrew. *While I don't own a carbon fork bike, I've ridden several of my friends' carbon bikes. *I don't think carbon has any magic effect on comfort, and AFAIK neither do the friends who bought those bikes. The first couple of guys to buy carbon seem to have done it before claims of magic comfort came out - at least, I don't recall such claims in the 1990s - and they never mentioned any such comfort. *One woman even bought a Zertz-equipped carbon bike a few years ago, and she specifically said she couldn't tell any comfort difference between her steel bikes. But to get technical, as we do here from time to time: *What would cause the difference? *As far as I know, once fit is dialed in, the main "comfort" effect (i.e. reduction in road shock) comes from flexibility in the vertical direction. *There's no way a typical carbon fork flexes significantly more in the vertical than a typical steel or aluminum fork. *Any difference is far, far smaller than the deflection of the tire. There might be a small effect from the reduction in fork mass that comes from using carbon fiber. *That is, once the fork mass has been accelerated upward by a bump, a massier fork will transmit more force to the rider's hands than a fork with less mass. *But the mass of the fork is a small percentage of the total mass being moved upward, so any difference due directly to fork mass reduction should be small, I think. *And it occurs to me, the smoothest riding cars and motorcycles tend to have larger sprung masses and smaller unsprung masses; for smooth ride, it's considered more beneficial to reduce the upward motion of the sprung mass, rather than to lessen that mass and thus allow more upward motion. *(We could discuss this, I suppose.) In any case, I think the claims for carbon forks put us back into "The princess and the pea" territory. You want comfort? Fit a fatter tire - if your fork will allow it, that is. *A great many carbon forks won't allow fatter tires. *Today's weird fashion is carbon plus near-zero tire clearance. *And there's no accounting for fashion. *Or for its sales pitches. - Frank Krygowski I recently did a floor pump rebuild. Customer wanted assurance that he could get his preferred 130psi from it so I did just that on my own front wheel, which was nearby. I sure did notice that running errands an hour later! I'm not surprised. *The difference in vertical deflection of a tire varies a _lot_ with tire pressure. The 3 speed bike I built last year gets used only for short utility rides, seldom more than five miles. *It's got 32mm tires on it, and I don't bother to pump them until they get quite soft, like 50 psi. *The cushy low pressure ride is kind of nice, but then I get worried about pinch flats. *130 psi would rattle out my tooth fillings, if the tires didn't blow off first. - Frank Krygowski Just make sure you spit out any amalgam fillings. |
#38
|
|||
|
|||
To carbon fork or not to carbon fork...
Frank Krygowski wrote:
On Oct 17, 5:43 pm, AMuzi wrote: On 10/17/2012 10:56 AM, Duane Hébert wrote: On 10/17/2012 10:17 AM, landotter wrote: On Oct 13, 9:05 pm, piscesboy wrote: I'm considering getting a road bike and considering whether to get the "standard" model or the same model with a carbon fork for $100 or so more. It's supposed to make for a more stable ride on rougher roads, but what are your conclusions/reviews/recommendations on this claim? Did the bike shop make this claim? Because it's bull****. Get a carbon fork if it comes with a bike you like, or if you're racing and it'll help you drop some grams. Otherwise, it doesn't matter. For comfort, large tires and cockpit details are far more important. You don't think that a carbon fork would be more comfortable than an aluminum fork on the same frame with 125 psi 700 x 23c tires? I don't. They are probably both adequately strong and of the same geometry as far as handling but I bet you could not tell them apart if similarly painted. I agree with Andrew. While I don't own a carbon fork bike, I've ridden several of my friends' carbon bikes. I don't think carbon has any magic effect on comfort, and AFAIK neither do the friends who bought those bikes. The first couple of guys to buy carbon seem to have done it before claims of magic comfort came out - at least, I don't recall such claims in the 1990s - and they never mentioned any such comfort. One woman even bought a Zertz-equipped carbon bike a few years ago, and she specifically said she couldn't tell any comfort difference between her steel bikes. But to get technical, as we do here from time to time: What would cause the difference? As far as I know, once fit is dialed in, the main "comfort" effect (i.e. reduction in road shock) comes from flexibility in the vertical direction. There's no way a typical carbon fork flexes significantly more in the vertical than a typical steel or aluminum fork. Any difference is far, far smaller than the deflection of the tire. There might be a small effect from the reduction in fork mass that comes from using carbon fiber. That is, once the fork mass has been accelerated upward by a bump, a massier fork will transmit more force to the rider's hands than a fork with less mass. But the mass of the fork is a small percentage of the total mass being moved upward, so any difference due directly to fork mass reduction should be small, I think. And it occurs to me, the smoothest riding cars and motorcycles tend to have larger sprung masses and smaller unsprung masses; for smooth ride, it's considered more beneficial to reduce the upward motion of the sprung mass, rather than to lessen that mass and thus allow more upward motion. (We could discuss this, I suppose.) In any case, I think the claims for carbon forks put us back into "The princess and the pea" territory. You want comfort? Fit a fatter tire - if your fork will allow it, that is. A great many carbon forks won't allow fatter tires. Today's weird fashion is carbon plus near-zero tire clearance. And there's no accounting for fashion. Or for its sales pitches. - Frank Krygowski, There may be differences in damping as well. Kerry |
#39
|
|||
|
|||
To carbon fork or not to carbon fork...
On Oct 18, 3:37*am, James wrote:
On Thursday, October 18, 2012 12:38:13 PM UTC+11, Frank Krygowski wrote: On Oct 17, 5:43*pm, AMuzi wrote: On 10/17/2012 10:56 AM, Duane Hébert wrote: On 10/17/2012 10:17 AM, landotter wrote: On Oct 13, 9:05 pm, piscesboy wrote: I'm considering getting a road bike and considering whether to get the "standard" model or the same model with a carbon fork for $100 or so more. It's supposed to make for a more stable ride on rougher roads, but what are your conclusions/reviews/recommendations on this claim? Did the bike shop make this claim? Because it's bull****. Get a carbon fork if it comes with a bike you like, or if you're racing and it'll help you drop some grams. Otherwise, it doesn't matter. For comfort, large tires and cockpit details are far more important. You don't think that a carbon fork would be more comfortable than an aluminum fork on the same frame with 125 psi 700 x 23c tires? I don't. They are probably both adequately strong and of the same geometry as far as handling but I bet you could not tell them apart if similarly painted. I agree with Andrew. *While I don't own a carbon fork bike, I've ridden several of my friends' carbon bikes. *I don't think carbon has any magic effect on comfort, and AFAIK neither do the friends who bought those bikes. The first couple of guys to buy carbon seem to have done it before claims of magic comfort came out - at least, I don't recall such claims in the 1990s - and they never mentioned any such comfort. *One woman even bought a Zertz-equipped carbon bike a few years ago, and she specifically said she couldn't tell any comfort difference between her steel bikes. I do not disbelieve those who complained about earlier all Al frames being harsh. *They had a bicycle (or more likely several bicycles) before their Al bike, and consequently had something to compare too. *It was because of these complaints that manufacturers have taken measures to improve comfort. Not all Al bikes are (were) harsh though, and certainly steel and CRFP can be made to be every bit as harsh or more if you want. Wheel design can also have some effect on perceived comfort. A mate and I swapped bikes while warming up before a race not long ago. *We both concluded that my steel frame felt stiffer than his Ti frame, though they are about the same size, have a CFRP fork, oversize tubes, hard saddle - and even though his wheels are (presumably) very rigid Zipp 404s. *When we swapped back, he mentioned it first, but I was already thinking it. *Materials can make perceivable differences in feel - even when outside dimensions look quite similar. Of course, my steel frame weighs about 500 g more and cost less than half as much ;-) But to get technical, as we do here from time to time: *What would cause the difference? *As far as I know, once fit is dialed in, the main "comfort" effect (i.e. reduction in road shock) comes from flexibility in the vertical direction. *There's no way a typical carbon fork flexes significantly more in the vertical than a typical steel or aluminum fork. *Any difference is far, far smaller than the deflection of the tire. There might be a small effect from the reduction in fork mass that comes from using carbon fiber. *That is, once the fork mass has been accelerated upward by a bump, a massier fork will transmit more force to the rider's hands than a fork with less mass. *But the mass of the "Massier"? *What was wrong with heavier, or "a fork with more mass"? fork is a small percentage of the total mass being moved upward, so any difference due directly to fork mass reduction should be small, I think. *And it occurs to me, the smoothest riding cars and motorcycles tend to have larger sprung masses and smaller unsprung masses; for smooth ride, it's considered more beneficial to reduce the upward motion of the sprung mass, rather than to lessen that mass and thus allow more upward motion. *(We could discuss this, I suppose.) I guess one question is where do you consider the spring? *A 23 mm tyre at 125 psi with little load on it doesn't deflect much. Perhaps the spring is in the wrists and arms. *Having a lighter front end is easier for these "suspension components" to absorb the movement and shock. One other thing is that some of the movement in a fork as you ride over bumps is backward and forward (rather than up and down). *This may contribute to the road "buzz" you feel. *CFRP will possibly damp that buzz more than metal. In any case, I think the claims for carbon forks put us back into "The princess and the pea" territory. You want comfort? Fit a fatter tire - if your fork will allow it, that is. *A great many carbon forks won't allow fatter tires. OTOH, if you look it is not so difficult to find CFRP forks that do have adequate tyre clearance and eyelets for mudguards. *A quick search yields.... http://www.ribblecycles.co.uk/sp/roa...lack-Rain-Wint... " RIBBLE Price Online price, a saving of 20% on Ribble prices. 1 1/8" ITS £109.95 £87.96 out of stock " They didn't last long. You do realise that in NW England it was, and maybe still is, for racing men to ride 120 miles in winter between 8:30 and 3:30 with either 2 cafe stops or a prolonged lunch stop? If that fork survives simple falls it is no surprise they are popular at the price. I like the fork I have on my racing bike, SL blades, with the spokes tensioned to provide minimal shock transmission to the rider at 20mph over some local cobbles. One may improve the ride comfort using any forks by modifying spokeline and tension but an overly stiff fork will overstress the wheel, possibly leading to early failure, or at the minimum a lesser accuracy in tracking and speed wobbles (although these mostly originate from the rear wheel, a low spoke count or thin gauge, as may be expected on a front wheel, will also encourage it). http://www.kinesisbikes.co.uk/products/forks/road/dc07 http://www.kinesisbikes.co.uk/products/forks/road/dc21 The cyclocross world offers more range. -- JS |
#40
|
|||
|
|||
To carbon fork or not to carbon fork...
On Oct 18, 2:13*pm, Duane Hébert wrote:
On 10/17/2012 08:32 PM, John B. wrote: On Wed, 17 Oct 2012 11:56:11 -0400, Duane Hébert wrote: On 10/17/2012 10:17 AM, landotter wrote: On Oct 13, 9:05 pm, piscesboy wrote: I'm considering getting a road bike and considering whether to get the "standard" model or the same model with a carbon fork for $100 or so more. It's supposed to make for a more stable ride on rougher roads, but what are your conclusions/reviews/recommendations on this claim? Did the bike shop make this claim? Because it's bull****. Get a carbon fork if it comes with a bike you like, or if you're racing and it'll help you drop some grams. Otherwise, it doesn't matter. For comfort, large tires and cockpit details are far more important. You don't think that a carbon fork would be more comfortable than an aluminum fork on the same frame with 125 psi 700 x 23c tires? I can't say for the aluminum but certainly my Giant TCR2 with a carbon fork and 300C 23 tires (or smaller) didn't feel any different, at least nothing that could be attributed to the fork, then a light steel bike road bike with the usual curved steel fork. So if there is a difference it is not memorable enough that one can notice it riding the same route on different days. I'm not saying that there is a difference. *Only that most of the bike shops seem to be saying that. Well, if you are doing the rounds, perhaps you can get them to be specific about differences. |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
FS: NEW 2006 Raleigh full carbon Team frame w/NEW Ritchey carbon fork | [email protected] | Marketplace | 1 | November 27th 06 12:09 AM |
Bianchi Axis 49cm frame w/Al fork and Carbon fork FS | [email protected] | Marketplace | 0 | July 7th 06 04:47 PM |
Wound-up carbon/carbon fork, 1" threaded 7 1/4 inch steerer $75 | RobInfo | Marketplace | 0 | September 28th 05 10:41 PM |
FA: 2003 GIANT TCR 0 CARBON FRAME, CARBON FORK, CARBON CAGES AND COMPUTER | Phil, Squid-in-Training | Marketplace | 0 | January 21st 05 03:07 PM |
Orbea Lobular Carbon frame/Zeus FCM carbon fork/integrated headset | Jonathan Page | Marketplace | 0 | August 8th 04 08:49 PM |