Chain noise
11-10-11, 08:39 AM
#1
Senior Member
Thread Starter
Join Date: May 2011
Location: NoVA
Posts: 1,421
Bikes: Specialized Allez Sport
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
Likes: 0
Liked 1 Time
in
1 Post
Chain noise
On both of my bikes, the chain is noisier when I'm on the smaller chainring (standard) regardless of what cog it is. There is no rubbing anywhere. Can anyone tell me why this is? Thanks.
11-10-11, 04:11 PM
#2
Senior Member
Join Date: Sep 2010
Location: Roswell, GA
Posts: 8,321
Bikes: '93 Trek 750, '92 Schwinn Crisscross, '93 Mongoose Alta
Mentioned: 30 Post(s)
Tagged: 0 Thread(s)
Quoted: 1441 Post(s)
Liked 1,095 Times
in
725 Posts
hyhuu: Just a guess but the chain makes a more acute bend (each link bends through a sharper angle) going onto and coming off of the smallest chainring. I'd think you would notice the same effect on the smalller cogs as well, though. The tension provided by the derailleur is lower and the derailleur wheel angles are different on the smaller chainrings and cogs, maybe that makes a difference.
11-11-11, 12:08 PM
#3
Senior Member
Thread Starter
Join Date: May 2011
Location: NoVA
Posts: 1,421
Bikes: Specialized Allez Sport
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
Likes: 0
Liked 1 Time
in
1 Post
hyhuu: Just a guess but the chain makes a more acute bend (each link bends through a sharper angle) going onto and coming off of the smallest chainring. I'd think you would notice the same effect on the smalller cogs as well, though. The tension provided by the derailleur is lower and the derailleur wheel angles are different on the smaller chainrings and cogs, maybe that makes a difference.
11-11-11, 01:35 PM
#4
Senior Member
Join Date: Apr 2009
Location: New Rochelle, NY
Posts: 39,065
Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter
Mentioned: 141 Post(s)
Tagged: 1 Thread(s)
Quoted: 5978 Post(s)
Liked 2,888 Times
in
1,608 Posts
I doubt it's related to the smaller diameter (more flex when coming on or off), because the difference in ring size isn't enough for any difference to be noticeable.
The biggest factors affecting chain noise - not counting lubrication - are chain or sprocket wear, cut of the sprocket teeth, and alignment. This assumes we're talking about chain/sprocket noise and the chain isn't actually rubbing anywhere.
Normal chain noise - sort of a gentle whirring or buzz - happens because the sprockets aren't actually round pulleys but ace as polygons causing the chain to rise and fall slightly as the teeth go by - think of it as the chain being wrapped around a 39 or 53 sided polygon. This sets up a vibration with a pitch equal to the rpm times the number of teeth. There's also a slight shift in the speed of the chain or sprocket as high and low diameter zones go by, which also contributes.
That's the normal or minimum noise of chain drives, but differences in the cuts of the sprocket teeth, or alignment of the system can increase the noise. For example when the chain comes from an angle, the teeth will hold the chain straight, and when they dis-engage the chain will shift sideways under tension. This repeats with every tooth, and can be a more or less sudden movement depending on how the teeth are beveled to a point. For an extreme example, ride big/big for a minute and listen carefully, and you'll hear it.
Chain or sprocket wear also add to noise especially when the chain is "stretched" to more than the original 1/2" pitch, by pin wear. When new each engaging tooth perfectly meets the space between the rollers, slipping in smoothly. When the chain is worn, the roller is slightly out of position and the front of the engaging tooth bumps into it as it slides in. If you've every ridden a ferry it's akin the the difference between a pilot who enters the slip perfectly centered vs.one who bumps the guides on either side as he enters. Again, this happens with every tooth.
As to why your two rings sound different, it could be the wear condition or the original cut of the teeth. It could also be that the pitch change brings it into a better hearing range for you. There's also more tension on the chain on smaller rings, both because of the greater crank leverage, and because you tend to use the inner for climbing or headwinds.
Those are the various possibilities, but other than intellectual curiosity, you should simply ignore it as a normal characteristic of chain drives. If it's loud enough to bug you, changing chain oils might quiet the drivetrain enough that you no longer notice it either way.
The biggest factors affecting chain noise - not counting lubrication - are chain or sprocket wear, cut of the sprocket teeth, and alignment. This assumes we're talking about chain/sprocket noise and the chain isn't actually rubbing anywhere.
Normal chain noise - sort of a gentle whirring or buzz - happens because the sprockets aren't actually round pulleys but ace as polygons causing the chain to rise and fall slightly as the teeth go by - think of it as the chain being wrapped around a 39 or 53 sided polygon. This sets up a vibration with a pitch equal to the rpm times the number of teeth. There's also a slight shift in the speed of the chain or sprocket as high and low diameter zones go by, which also contributes.
That's the normal or minimum noise of chain drives, but differences in the cuts of the sprocket teeth, or alignment of the system can increase the noise. For example when the chain comes from an angle, the teeth will hold the chain straight, and when they dis-engage the chain will shift sideways under tension. This repeats with every tooth, and can be a more or less sudden movement depending on how the teeth are beveled to a point. For an extreme example, ride big/big for a minute and listen carefully, and you'll hear it.
Chain or sprocket wear also add to noise especially when the chain is "stretched" to more than the original 1/2" pitch, by pin wear. When new each engaging tooth perfectly meets the space between the rollers, slipping in smoothly. When the chain is worn, the roller is slightly out of position and the front of the engaging tooth bumps into it as it slides in. If you've every ridden a ferry it's akin the the difference between a pilot who enters the slip perfectly centered vs.one who bumps the guides on either side as he enters. Again, this happens with every tooth.
As to why your two rings sound different, it could be the wear condition or the original cut of the teeth. It could also be that the pitch change brings it into a better hearing range for you. There's also more tension on the chain on smaller rings, both because of the greater crank leverage, and because you tend to use the inner for climbing or headwinds.
Those are the various possibilities, but other than intellectual curiosity, you should simply ignore it as a normal characteristic of chain drives. If it's loud enough to bug you, changing chain oils might quiet the drivetrain enough that you no longer notice it either way.
__________________
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
11-12-11, 03:37 PM
#5
Senior Member
Thread Starter
Join Date: May 2011
Location: NoVA
Posts: 1,421
Bikes: Specialized Allez Sport
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
Likes: 0
Liked 1 Time
in
1 Post
I doubt it's related to the smaller diameter (more flex when coming on or off), because the difference in ring size isn't enough for any difference to be noticeable.
The biggest factors affecting chain noise - not counting lubrication - are chain or sprocket wear, cut of the sprocket teeth, and alignment. This assumes we're talking about chain/sprocket noise and the chain isn't actually rubbing anywhere.
Normal chain noise - sort of a gentle whirring or buzz - happens because the sprockets aren't actually round pulleys but ace as polygons causing the chain to rise and fall slightly as the teeth go by - think of it as the chain being wrapped around a 39 or 53 sided polygon. This sets up a vibration with a pitch equal to the rpm times the number of teeth. There's also a slight shift in the speed of the chain or sprocket as high and low diameter zones go by, which also contributes.
That's the normal or minimum noise of chain drives, but differences in the cuts of the sprocket teeth, or alignment of the system can increase the noise. For example when the chain comes from an angle, the teeth will hold the chain straight, and when they dis-engage the chain will shift sideways under tension. This repeats with every tooth, and can be a more or less sudden movement depending on how the teeth are beveled to a point. For an extreme example, ride big/big for a minute and listen carefully, and you'll hear it.
Chain or sprocket wear also add to noise especially when the chain is "stretched" to more than the original 1/2" pitch, by pin wear. When new each engaging tooth perfectly meets the space between the rollers, slipping in smoothly. When the chain is worn, the roller is slightly out of position and the front of the engaging tooth bumps into it as it slides in. If you've every ridden a ferry it's akin the the difference between a pilot who enters the slip perfectly centered vs.one who bumps the guides on either side as he enters. Again, this happens with every tooth.
As to why your two rings sound different, it could be the wear condition or the original cut of the teeth. It could also be that the pitch change brings it into a better hearing range for you. There's also more tension on the chain on smaller rings, both because of the greater crank leverage, and because you tend to use the inner for climbing or headwinds.
Those are the various possibilities, but other than intellectual curiosity, you should simply ignore it as a normal characteristic of chain drives. If it's loud enough to bug you, changing chain oils might quiet the drivetrain enough that you no longer notice it either way.
The biggest factors affecting chain noise - not counting lubrication - are chain or sprocket wear, cut of the sprocket teeth, and alignment. This assumes we're talking about chain/sprocket noise and the chain isn't actually rubbing anywhere.
Normal chain noise - sort of a gentle whirring or buzz - happens because the sprockets aren't actually round pulleys but ace as polygons causing the chain to rise and fall slightly as the teeth go by - think of it as the chain being wrapped around a 39 or 53 sided polygon. This sets up a vibration with a pitch equal to the rpm times the number of teeth. There's also a slight shift in the speed of the chain or sprocket as high and low diameter zones go by, which also contributes.
That's the normal or minimum noise of chain drives, but differences in the cuts of the sprocket teeth, or alignment of the system can increase the noise. For example when the chain comes from an angle, the teeth will hold the chain straight, and when they dis-engage the chain will shift sideways under tension. This repeats with every tooth, and can be a more or less sudden movement depending on how the teeth are beveled to a point. For an extreme example, ride big/big for a minute and listen carefully, and you'll hear it.
Chain or sprocket wear also add to noise especially when the chain is "stretched" to more than the original 1/2" pitch, by pin wear. When new each engaging tooth perfectly meets the space between the rollers, slipping in smoothly. When the chain is worn, the roller is slightly out of position and the front of the engaging tooth bumps into it as it slides in. If you've every ridden a ferry it's akin the the difference between a pilot who enters the slip perfectly centered vs.one who bumps the guides on either side as he enters. Again, this happens with every tooth.
As to why your two rings sound different, it could be the wear condition or the original cut of the teeth. It could also be that the pitch change brings it into a better hearing range for you. There's also more tension on the chain on smaller rings, both because of the greater crank leverage, and because you tend to use the inner for climbing or headwinds.
Those are the various possibilities, but other than intellectual curiosity, you should simply ignore it as a normal characteristic of chain drives. If it's loud enough to bug you, changing chain oils might quiet the drivetrain enough that you no longer notice it either way.
