Is there any reason for the rear frame and bottom bracket to be asymmetric?
up vote
3
down vote
favorite
I just received a new non-brand carbon frame and immediately noticed that the bottom bracket looks to stick out significantly more to one side than the other, and the rear bottom forks also seem to be have slightly different dimensions - both somewhat asymmetric along the center line of the frame.
Is there any reason for a frame to be designed like this? Does it have something to do with it being a disc brake compatible frame? Or is this more likely a manufacturing / design problem?
Here are some images:
Thanks! I really appreciate any help + advice.
frames bottom-bracket carbon design
edited Nov 9 at 21:56
Mike
3,20611025
asked Nov 9 at 16:20
aakzeman
162
add a comment |
up vote
3
down vote
favorite
I just received a new non-brand carbon frame and immediately noticed that the bottom bracket looks to stick out significantly more to one side than the other, and the rear bottom forks also seem to be have slightly different dimensions - both somewhat asymmetric along the center line of the frame.
Is there any reason for a frame to be designed like this? Does it have something to do with it being a disc brake compatible frame? Or is this more likely a manufacturing / design problem?
Here are some images:
Thanks! I really appreciate any help + advice.
frames bottom-bracket carbon design
edited Nov 9 at 21:56
Mike
3,20611025
asked Nov 9 at 16:20
aakzeman
162
It's the chainstays that are asymmetrical, not the frame itself. If you want to be 100% sure whether the frame is symmetrical, run a thin rope from the rear dropouts (both left and right) to the head tube and measure the distance from the rope to the down tube. The distance on both sides should be identical (within the measurement error).
– Mike
Nov 9 at 21:59
1
The magnitude of the asymmetry around the bottom bracket makes it very clear that this asymmetry is by design. You wouldn't produce such an asymmetry by accident. What you are seeing is a form that follows function, making the chain-stay go out of the way for the chain-rings.
– cmaster
Nov 9 at 22:12
add a comment |
up vote
3
down vote
favorite
up vote
3
down vote
favorite
I just received a new non-brand carbon frame and immediately noticed that the bottom bracket looks to stick out significantly more to one side than the other, and the rear bottom forks also seem to be have slightly different dimensions - both somewhat asymmetric along the center line of the frame.
Is there any reason for a frame to be designed like this? Does it have something to do with it being a disc brake compatible frame? Or is this more likely a manufacturing / design problem?
Here are some images:
Thanks! I really appreciate any help + advice.
frames bottom-bracket carbon design
edited Nov 9 at 21:56
Mike
3,20611025
asked Nov 9 at 16:20
aakzeman
162
I just received a new non-brand carbon frame and immediately noticed that the bottom bracket looks to stick out significantly more to one side than the other, and the rear bottom forks also seem to be have slightly different dimensions - both somewhat asymmetric along the center line of the frame.
Is there any reason for a frame to be designed like this? Does it have something to do with it being a disc brake compatible frame? Or is this more likely a manufacturing / design problem?
Here are some images:
Thanks! I really appreciate any help + advice.
frames bottom-bracket carbon design
frames bottom-bracket carbon design
edited Nov 9 at 21:56
Mike
3,20611025
asked Nov 9 at 16:20
aakzeman
162
edited Nov 9 at 21:56
Mike
3,20611025
asked Nov 9 at 16:20
aakzeman
162
edited Nov 9 at 21:56
Mike
3,20611025
edited Nov 9 at 21:56
Mike
3,20611025
edited Nov 9 at 21:56
Mike
3,20611025
3,20611025
asked Nov 9 at 16:20
aakzeman
162
asked Nov 9 at 16:20
aakzeman
162
asked Nov 9 at 16:20
aakzeman
162
162
It's the chainstays that are asymmetrical, not the frame itself. If you want to be 100% sure whether the frame is symmetrical, run a thin rope from the rear dropouts (both left and right) to the head tube and measure the distance from the rope to the down tube. The distance on both sides should be identical (within the measurement error).
– Mike
Nov 9 at 21:59
1
The magnitude of the asymmetry around the bottom bracket makes it very clear that this asymmetry is by design. You wouldn't produce such an asymmetry by accident. What you are seeing is a form that follows function, making the chain-stay go out of the way for the chain-rings.
– cmaster
Nov 9 at 22:12
add a comment |
It's the chainstays that are asymmetrical, not the frame itself. If you want to be 100% sure whether the frame is symmetrical, run a thin rope from the rear dropouts (both left and right) to the head tube and measure the distance from the rope to the down tube. The distance on both sides should be identical (within the measurement error).
– Mike
Nov 9 at 21:59
1
The magnitude of the asymmetry around the bottom bracket makes it very clear that this asymmetry is by design. You wouldn't produce such an asymmetry by accident. What you are seeing is a form that follows function, making the chain-stay go out of the way for the chain-rings.
– cmaster
Nov 9 at 22:12
It's the chainstays that are asymmetrical, not the frame itself. If you want to be 100% sure whether the frame is symmetrical, run a thin rope from the rear dropouts (both left and right) to the head tube and measure the distance from the rope to the down tube. The distance on both sides should be identical (within the measurement error).
– Mike
Nov 9 at 21:59
It's the chainstays that are asymmetrical, not the frame itself. If you want to be 100% sure whether the frame is symmetrical, run a thin rope from the rear dropouts (both left and right) to the head tube and measure the distance from the rope to the down tube. The distance on both sides should be identical (within the measurement error).
– Mike
Nov 9 at 21:59
1
1
The magnitude of the asymmetry around the bottom bracket makes it very clear that this asymmetry is by design. You wouldn't produce such an asymmetry by accident. What you are seeing is a form that follows function, making the chain-stay go out of the way for the chain-rings.
– cmaster
Nov 9 at 22:12
The magnitude of the asymmetry around the bottom bracket makes it very clear that this asymmetry is by design. You wouldn't produce such an asymmetry by accident. What you are seeing is a form that follows function, making the chain-stay go out of the way for the chain-rings.
– cmaster
Nov 9 at 22:12
add a comment |
4 Answers
4
active
oldest
votes
up vote
5
down vote
The bottom bracket shell does not really stick out more on the drive side, it's symmetrical around the center line of the frame. The non drive side bottom bracket shell and chainstay are just more built up.
On reason is providing clearance for the chainrings on the drive side.
answered Nov 9 at 16:34
Argenti Apparatus
31.9k23481
1
Put in a rear wheel and you'll notice that the tyre is exactly behind the seat tube.
– Carel
Nov 9 at 16:40
add a comment |
up vote
3
down vote
Some bikes have a drive-side chainstay with a downward kink to minimize chain slap. Many bikes need to get creative with the path that the drive-side chainstay travels along the Y axis, in order to "thread the needle" between the rear tire and the chainrings, which can be a very tight fit. It's fairly common for the drive-side chainstay to be stouter, because that's what is most directly loaded when you're pedaling. Cannondale even uses asymmetric bottom brackets.
answered Nov 9 at 18:49
Adam Rice
5,0391330
1
On a road bike this would be to reduce chain suck, rather than chain slap. Giant does this on their road frames rather than a metal plate attached to the frame to deflect the chain .
– Rider_X
Nov 9 at 19:48
Cool, I did not know that.
– Adam Rice
Nov 10 at 0:29
add a comment |
up vote
1
down vote
Is there any reason for the rear frame and bottom bracket to be asymmetric?
The crankset, chain, and gearing are all on one side, making just about every standard bicycle asymmetric.
Given that there are different asymmetric forces on the parts of the frame because of that, there's plenty of reason for a frame to be asymmetric.
answered Nov 9 at 16:22
Andrew Henle
88146
Thank you for the response. I understand that all frames will have some differences between the two sides to compensate for the spacing of the crankset, chain, etc., but in this instance it looks to be much more pronounced than usual. Would you mind commenting on the images I included?
– aakzeman
Nov 9 at 16:30
add a comment |
up vote
1
down vote
Or is this more likely a manufacturing / design problem?
Absolutely not. Carbon frames are made using moulds and jigs so every frame that a factory produces should be exactly the same shape, except for tiny variations caused by hand-finishing. This recent GCN video shows the processes involved in making carbon frames, though be aware that it promotes Look bicycles quite heavily: How are Carbon Fibre Bikes Made? | LOOK Cycle Factory Tour.
Asking if it's a design problem presupposes that it's a problem at all, and the other answers explain why it's not. And bear in mind that a manufacturer who released a product with something so obviously "wrong" about it would have had to make an enormous series of huge mistakes.
answered Nov 10 at 13:44
David Richerby
10.1k33151
add a comment |
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4 Answers
4
active
oldest
votes
4 Answers
4
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
5
down vote
The bottom bracket shell does not really stick out more on the drive side, it's symmetrical around the center line of the frame. The non drive side bottom bracket shell and chainstay are just more built up.
On reason is providing clearance for the chainrings on the drive side.
answered Nov 9 at 16:34
Argenti Apparatus
31.9k23481
1
Put in a rear wheel and you'll notice that the tyre is exactly behind the seat tube.
– Carel
Nov 9 at 16:40
add a comment |
up vote
5
down vote
The bottom bracket shell does not really stick out more on the drive side, it's symmetrical around the center line of the frame. The non drive side bottom bracket shell and chainstay are just more built up.
On reason is providing clearance for the chainrings on the drive side.
answered Nov 9 at 16:34
Argenti Apparatus
31.9k23481
1
Put in a rear wheel and you'll notice that the tyre is exactly behind the seat tube.
– Carel
Nov 9 at 16:40
add a comment |
up vote
5
down vote
up vote
5
down vote
The bottom bracket shell does not really stick out more on the drive side, it's symmetrical around the center line of the frame. The non drive side bottom bracket shell and chainstay are just more built up.
On reason is providing clearance for the chainrings on the drive side.
answered Nov 9 at 16:34
Argenti Apparatus
31.9k23481
The bottom bracket shell does not really stick out more on the drive side, it's symmetrical around the center line of the frame. The non drive side bottom bracket shell and chainstay are just more built up.
On reason is providing clearance for the chainrings on the drive side.
answered Nov 9 at 16:34
Argenti Apparatus
31.9k23481
answered Nov 9 at 16:34
Argenti Apparatus
31.9k23481
answered Nov 9 at 16:34
Argenti Apparatus
31.9k23481
answered Nov 9 at 16:34
Argenti Apparatus
31.9k23481
31.9k23481
1
Put in a rear wheel and you'll notice that the tyre is exactly behind the seat tube.
– Carel
Nov 9 at 16:40
add a comment |
1
Put in a rear wheel and you'll notice that the tyre is exactly behind the seat tube.
– Carel
Nov 9 at 16:40
1
1
Put in a rear wheel and you'll notice that the tyre is exactly behind the seat tube.
– Carel
Nov 9 at 16:40
Put in a rear wheel and you'll notice that the tyre is exactly behind the seat tube.
– Carel
Nov 9 at 16:40
add a comment |
up vote
3
down vote
Some bikes have a drive-side chainstay with a downward kink to minimize chain slap. Many bikes need to get creative with the path that the drive-side chainstay travels along the Y axis, in order to "thread the needle" between the rear tire and the chainrings, which can be a very tight fit. It's fairly common for the drive-side chainstay to be stouter, because that's what is most directly loaded when you're pedaling. Cannondale even uses asymmetric bottom brackets.
answered Nov 9 at 18:49
Adam Rice
5,0391330
1
On a road bike this would be to reduce chain suck, rather than chain slap. Giant does this on their road frames rather than a metal plate attached to the frame to deflect the chain .
– Rider_X
Nov 9 at 19:48
Cool, I did not know that.
– Adam Rice
Nov 10 at 0:29
add a comment |
up vote
3
down vote
Some bikes have a drive-side chainstay with a downward kink to minimize chain slap. Many bikes need to get creative with the path that the drive-side chainstay travels along the Y axis, in order to "thread the needle" between the rear tire and the chainrings, which can be a very tight fit. It's fairly common for the drive-side chainstay to be stouter, because that's what is most directly loaded when you're pedaling. Cannondale even uses asymmetric bottom brackets.
answered Nov 9 at 18:49
Adam Rice
5,0391330
1
On a road bike this would be to reduce chain suck, rather than chain slap. Giant does this on their road frames rather than a metal plate attached to the frame to deflect the chain .
– Rider_X
Nov 9 at 19:48
Cool, I did not know that.
– Adam Rice
Nov 10 at 0:29
add a comment |
up vote
3
down vote
up vote
3
down vote
Some bikes have a drive-side chainstay with a downward kink to minimize chain slap. Many bikes need to get creative with the path that the drive-side chainstay travels along the Y axis, in order to "thread the needle" between the rear tire and the chainrings, which can be a very tight fit. It's fairly common for the drive-side chainstay to be stouter, because that's what is most directly loaded when you're pedaling. Cannondale even uses asymmetric bottom brackets.
answered Nov 9 at 18:49
Adam Rice
5,0391330
Some bikes have a drive-side chainstay with a downward kink to minimize chain slap. Many bikes need to get creative with the path that the drive-side chainstay travels along the Y axis, in order to "thread the needle" between the rear tire and the chainrings, which can be a very tight fit. It's fairly common for the drive-side chainstay to be stouter, because that's what is most directly loaded when you're pedaling. Cannondale even uses asymmetric bottom brackets.
answered Nov 9 at 18:49
Adam Rice
5,0391330
answered Nov 9 at 18:49
Adam Rice
5,0391330
answered Nov 9 at 18:49
Adam Rice
5,0391330
answered Nov 9 at 18:49
Adam Rice
5,0391330
5,0391330
1
On a road bike this would be to reduce chain suck, rather than chain slap. Giant does this on their road frames rather than a metal plate attached to the frame to deflect the chain .
– Rider_X
Nov 9 at 19:48
Cool, I did not know that.
– Adam Rice
Nov 10 at 0:29
add a comment |
1
On a road bike this would be to reduce chain suck, rather than chain slap. Giant does this on their road frames rather than a metal plate attached to the frame to deflect the chain .
– Rider_X
Nov 9 at 19:48
Cool, I did not know that.
– Adam Rice
Nov 10 at 0:29
1
1
On a road bike this would be to reduce chain suck, rather than chain slap. Giant does this on their road frames rather than a metal plate attached to the frame to deflect the chain .
– Rider_X
Nov 9 at 19:48
On a road bike this would be to reduce chain suck, rather than chain slap. Giant does this on their road frames rather than a metal plate attached to the frame to deflect the chain .
– Rider_X
Nov 9 at 19:48
Cool, I did not know that.
– Adam Rice
Nov 10 at 0:29
Cool, I did not know that.
– Adam Rice
Nov 10 at 0:29
add a comment |
up vote
1
down vote
Is there any reason for the rear frame and bottom bracket to be asymmetric?
The crankset, chain, and gearing are all on one side, making just about every standard bicycle asymmetric.
Given that there are different asymmetric forces on the parts of the frame because of that, there's plenty of reason for a frame to be asymmetric.
answered Nov 9 at 16:22
Andrew Henle
88146
Thank you for the response. I understand that all frames will have some differences between the two sides to compensate for the spacing of the crankset, chain, etc., but in this instance it looks to be much more pronounced than usual. Would you mind commenting on the images I included?
– aakzeman
Nov 9 at 16:30
add a comment |
up vote
1
down vote
Is there any reason for the rear frame and bottom bracket to be asymmetric?
The crankset, chain, and gearing are all on one side, making just about every standard bicycle asymmetric.
Given that there are different asymmetric forces on the parts of the frame because of that, there's plenty of reason for a frame to be asymmetric.
answered Nov 9 at 16:22
Andrew Henle
88146
Thank you for the response. I understand that all frames will have some differences between the two sides to compensate for the spacing of the crankset, chain, etc., but in this instance it looks to be much more pronounced than usual. Would you mind commenting on the images I included?
– aakzeman
Nov 9 at 16:30
add a comment |
up vote
1
down vote
up vote
1
down vote
Is there any reason for the rear frame and bottom bracket to be asymmetric?
The crankset, chain, and gearing are all on one side, making just about every standard bicycle asymmetric.
Given that there are different asymmetric forces on the parts of the frame because of that, there's plenty of reason for a frame to be asymmetric.
answered Nov 9 at 16:22
Andrew Henle
88146
Is there any reason for the rear frame and bottom bracket to be asymmetric?
The crankset, chain, and gearing are all on one side, making just about every standard bicycle asymmetric.
Given that there are different asymmetric forces on the parts of the frame because of that, there's plenty of reason for a frame to be asymmetric.
answered Nov 9 at 16:22
Andrew Henle
88146
answered Nov 9 at 16:22
Andrew Henle
88146
answered Nov 9 at 16:22
Andrew Henle
88146
answered Nov 9 at 16:22
Andrew Henle
88146
88146
Thank you for the response. I understand that all frames will have some differences between the two sides to compensate for the spacing of the crankset, chain, etc., but in this instance it looks to be much more pronounced than usual. Would you mind commenting on the images I included?
– aakzeman
Nov 9 at 16:30
add a comment |
Thank you for the response. I understand that all frames will have some differences between the two sides to compensate for the spacing of the crankset, chain, etc., but in this instance it looks to be much more pronounced than usual. Would you mind commenting on the images I included?
– aakzeman
Nov 9 at 16:30
Thank you for the response. I understand that all frames will have some differences between the two sides to compensate for the spacing of the crankset, chain, etc., but in this instance it looks to be much more pronounced than usual. Would you mind commenting on the images I included?
– aakzeman
Nov 9 at 16:30
Thank you for the response. I understand that all frames will have some differences between the two sides to compensate for the spacing of the crankset, chain, etc., but in this instance it looks to be much more pronounced than usual. Would you mind commenting on the images I included?
– aakzeman
Nov 9 at 16:30
add a comment |
up vote
1
down vote
Or is this more likely a manufacturing / design problem?
Absolutely not. Carbon frames are made using moulds and jigs so every frame that a factory produces should be exactly the same shape, except for tiny variations caused by hand-finishing. This recent GCN video shows the processes involved in making carbon frames, though be aware that it promotes Look bicycles quite heavily: How are Carbon Fibre Bikes Made? | LOOK Cycle Factory Tour.
Asking if it's a design problem presupposes that it's a problem at all, and the other answers explain why it's not. And bear in mind that a manufacturer who released a product with something so obviously "wrong" about it would have had to make an enormous series of huge mistakes.
answered Nov 10 at 13:44
David Richerby
10.1k33151
add a comment |
up vote
1
down vote
Or is this more likely a manufacturing / design problem?
Absolutely not. Carbon frames are made using moulds and jigs so every frame that a factory produces should be exactly the same shape, except for tiny variations caused by hand-finishing. This recent GCN video shows the processes involved in making carbon frames, though be aware that it promotes Look bicycles quite heavily: How are Carbon Fibre Bikes Made? | LOOK Cycle Factory Tour.
Asking if it's a design problem presupposes that it's a problem at all, and the other answers explain why it's not. And bear in mind that a manufacturer who released a product with something so obviously "wrong" about it would have had to make an enormous series of huge mistakes.
answered Nov 10 at 13:44
David Richerby
10.1k33151
add a comment |
up vote
1
down vote
up vote
1
down vote
Or is this more likely a manufacturing / design problem?
Absolutely not. Carbon frames are made using moulds and jigs so every frame that a factory produces should be exactly the same shape, except for tiny variations caused by hand-finishing. This recent GCN video shows the processes involved in making carbon frames, though be aware that it promotes Look bicycles quite heavily: How are Carbon Fibre Bikes Made? | LOOK Cycle Factory Tour.
Asking if it's a design problem presupposes that it's a problem at all, and the other answers explain why it's not. And bear in mind that a manufacturer who released a product with something so obviously "wrong" about it would have had to make an enormous series of huge mistakes.
answered Nov 10 at 13:44
David Richerby
10.1k33151
Or is this more likely a manufacturing / design problem?
Absolutely not. Carbon frames are made using moulds and jigs so every frame that a factory produces should be exactly the same shape, except for tiny variations caused by hand-finishing. This recent GCN video shows the processes involved in making carbon frames, though be aware that it promotes Look bicycles quite heavily: How are Carbon Fibre Bikes Made? | LOOK Cycle Factory Tour.
Asking if it's a design problem presupposes that it's a problem at all, and the other answers explain why it's not. And bear in mind that a manufacturer who released a product with something so obviously "wrong" about it would have had to make an enormous series of huge mistakes.
answered Nov 10 at 13:44
David Richerby
10.1k33151
answered Nov 10 at 13:44
David Richerby
10.1k33151
answered Nov 10 at 13:44
David Richerby
10.1k33151
answered Nov 10 at 13:44
David Richerby
10.1k33151
10.1k33151
add a comment |
add a comment |
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It's the chainstays that are asymmetrical, not the frame itself. If you want to be 100% sure whether the frame is symmetrical, run a thin rope from the rear dropouts (both left and right) to the head tube and measure the distance from the rope to the down tube. The distance on both sides should be identical (within the measurement error).
– Mike
Nov 9 at 21:59
1
The magnitude of the asymmetry around the bottom bracket makes it very clear that this asymmetry is by design. You wouldn't produce such an asymmetry by accident. What you are seeing is a form that follows function, making the chain-stay go out of the way for the chain-rings.
– cmaster
Nov 9 at 22:12