I have had two situation which cause chain skip which don't fit the usual profile: the parts are all new (they have the correct pitch) and there are no stiff links.
1. Has anyone ever had teeth on the sprocket that were too _wide_? I have one sprocket in the cassette which has three teeth which will not allow the thinner portion of a link to sit on them without excessive force. This causes the chain to skip. This is a seven-speed cassette, using a so-called eight-speed chain (which is the same size as a seven-speed chain, and anyway, none of the other sprockets are too wide for it). Can I safely grind away some of the offending teeth without causing other problems?
2. My old-style chain (with bushings) skips on the 11-tooth sprocket, but a bushing-less chain does not. I repeat: everything is in pitch here; I have compared the two chains carefully and they have identical pitch. It appears that the chain with bushings is slightly wider, but I don't see how that could be a problem. The other difference I observe is that the skipping chain has a slightly stiffer lubricant on it. (Both chains have the original factory lubrication.) All links will flex under their own weight, but the skipping chain seems a little more sluggish. Do you have any suggestions on how stop the skipping? Right now it's either throw away a brand new chain, or never use the top gear, neither of which seems that great.
On 17 May 2004 13:21:48 -0700, [email hidden] (Karl Nelson)
Quoted message said:
I have had two situation which cause chain skip which don't fit the usual profile: the parts are all new (they have the correct pitch) and there are no stiff links.
1. Has anyone ever had teeth on the sprocket that were too _wide_? I have one sprocket in the cassette which has three teeth which will not allow the thinner portion of a link to sit on them without excessive force. This causes the chain to skip. This is a seven-speed cassette, using a so-called eight-speed chain (which is the same size as a seven-speed chain, and anyway, none of the other sprockets are too wide for it). Can I safely grind away some of the offending teeth without causing other problems?
2. My old-style chain (with bushings) skips on the 11-tooth sprocket, but a bushing-less chain does not. I repeat: everything is in pitch here; I have compared the two chains carefully and they have identical pitch. It appears that the chain with bushings is slightly wider, but I don't see how that could be a problem. The other difference I observe is that the skipping chain has a slightly stiffer lubricant on it. (Both chains have the original factory lubrication.) All links will flex under their own weight, but the skipping chain seems a little more sluggish. Do you have any suggestions on how stop the skipping? Right now it's either throw away a brand new chain, or never use the top gear, neither of which seems that great.
Thanks, Karl.
Dear Karl,
For what it's worth, I slather my chain with fairly stiff 85w-140 gear oil and it doesn't skip on my 7-speed 53 x 11 Shimano with an SRAM PC48 chain.
Could your chain line be placing the 11-tooth at a greater than usual angle?
I have had two situation which cause chain skip which don't fit the usual profile: the parts are all new (they have the correct pitch) and there are no stiff links. 1. Has anyone ever had teeth on the sprocket that were too _wide_? I have one sprocket in the cassette which has three teeth which will not allow the thinner portion of a link to sit on them without excessive force. This causes the chain to skip. This is a seven- speed cassette, using a so-called eight-speed chain (which is the same size as a seven-speed chain, and anyway, none of the other sprockets are too wide for it). Can I safely grind away some of the offending teeth without causing other problems? 2. My old-style chain (with bushings) skips on the 11-tooth sprocket, but a bushing-less chain does not. I repeat: everything is in pitch here; I have compared the two chains carefully and they have identical pitch. It appears that the chain with bushings is slightly wider, but I don't see how that could be a problem. The other difference I observe is that the skipping chain has a slightly stiffer lubricant on it. (Both chains have the original factory lubrication.) All links will flex under their own weight, but the skipping chain seems a little more sluggish. Do you have any suggestions on how stop the skipping? Right now it's either throw away a brand new chain, or never use the top gear, neither of which seems that great. Thanks, Karl.
1. as an example... Shimano IG Seven Speed uses cogs that are 2.35 mm wide. Shimano HG Seven speed uses cogs that are 1.85 mm wide. I don't know what brand or model you are using, but there are significant differences in cogs, thickness, and chains made for the system. What 8 speed chain are you using? Most 8 speed chains are "expecting" a cog with thickness near 1.8 mm.
2. Different chains have differing amounts of side-to-side flexibility, and different contours. As pointed out in #1, they also have different dimensions.
I once had a situation similar to #1 (teeth too wide) occur. When I looked at it closely, it appeared that the chain had "mashed" the contact side of the teeth, effectively widening them and keeping the chain from seating. This was on a 7 speed freewheel (SRAM, if I remember). I like to tell myself this happened because I am so powerful.....
Lyle
"Karl Nelson" <[email hidden]> wrote in message news:[email hidden]...
Quoted message said:
I have had two situation which cause chain skip which don't fit the usual profile: the parts are all new (they have the correct pitch) and there are no stiff links.
1. Has anyone ever had teeth on the sprocket that were too _wide_? I have one sprocket in the cassette which has three teeth which will not allow the thinner portion of a link to sit on them without excessive force. This causes the chain to skip. This is a seven-speed cassette, using a so-called eight-speed chain (which is the same size as a seven-speed chain, and anyway, none of the other sprockets are too wide for it). Can I safely grind away some of the offending teeth without causing other problems?
I have had two situation which cause chain skip which don't fit the usual profile: the parts are all new (they have the correct pitch) and there are no stiff links.
1. Has anyone ever had teeth on the sprocket that were too _wide_? I have one sprocket in the cassette which has three teeth which will not allow the thinner portion of a link to sit on them without excessive force. This causes the chain to skip. This is a seven-speed cassette, using a so-called eight-speed chain (which is the same size as a seven-speed chain, and anyway, none of the other sprockets are too wide for it). Can I safely grind away some of the offending teeth without causing other problems?
2. My old-style chain (with bushings) skips on the 11-tooth sprocket, but a bushing-less chain does not. I repeat: everything is in pitch here; I have compared the two chains carefully and they have identical pitch. It appears that the chain with bushings is slightly wider, but I don't see how that could be a problem. The other difference I observe is that the skipping chain has a slightly stiffer lubricant on it. (Both chains have the original factory lubrication.) All links will flex under their own weight, but the skipping chain seems a little more sluggish. Do you have any suggestions on how stop the skipping? Right now it's either throw away a brand new chain, or never use the top gear, neither of which seems that great.
An outside guess - have you missed a spacer from under the 11T sprocket, if one is required? Do the sprockets look the same distance apart?
