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won't shift to granny
I'm having problems (again) shifting from my middle to granny under
load. I just replaced my moderately worn 40t middle with a new 38t, and the problem crept up again. I have already taken the measures of filing away the portion of the derailer that conatcts the frame, filing a small groove in the seat tube itself, and even moving my chainline outward about a mm via a BB spacer, and still no success. It shifts fine when not under load, but once you start up an incline, forget it, it won't go. Its an Ultegra der. and TA Alize rings. So now I'm thinking I'll file the tops off of two consectutive teeth in the middle ring to aid the shift. Don't some chainrings include this as a feature? A) Think this will help? B) If I do this, where on the ring (relative to the right crankarm) would I file the teeth? C) Any other suggestions? Thanks, Kyle |
#2
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Kyle.B.H. wrote: I'm having problems (again) shifting from my middle to granny under load. I just replaced my moderately worn 40t middle with a new 38t, and the problem crept up again. I have already taken the measures of filing away the portion of the derailer that conatcts the frame, filing a small groove in the seat tube itself, and even moving my chainline outward about a mm via a BB spacer, and still no success. It shifts fine when not under load, but once you start up an incline, forget it, it won't go. Its an Ultegra der. and TA Alize rings. So now I'm thinking I'll file the tops off of two consectutive teeth in the middle ring to aid the shift. Don't some chainrings include this as a feature? A) Think this will help? B) If I do this, where on the ring (relative to the right crankarm) would I file the teeth? C) Any other suggestions? Thanks, Kyle Perhaps the 6603 front der which is designed for a 39t middle ring, with the appropriate ramps to get the chain to the granny. |
#3
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"Qui si parla Campagnolo" wrote in message
oups.com... Kyle.B.H. wrote: I'm having problems (again) shifting from my middle to granny under load. I just replaced my moderately worn 40t middle with a new 38t, and the problem crept up again. I have already taken the measures of filing away the portion of the derailer that conatcts the frame, filing a small groove in the seat tube itself, and even moving my chainline outward about a mm via a BB spacer, and still no success. It shifts fine when not under load, but once you start up an incline, forget it, it won't go. Its an Ultegra der. and TA Alize rings. So now I'm thinking I'll file the tops off of two consectutive teeth in the middle ring to aid the shift. Don't some chainrings include this as a feature? A) Think this will help? B) If I do this, where on the ring (relative to the right crankarm) would I file the teeth? C) Any other suggestions? Thanks, Kyle Perhaps the 6603 front der which is designed for a 39t middle ring, with the appropriate ramps to get the chain to the granny. I was under the impression that shifting the front "under load" wasn't a plan. Bill |
#4
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Bill wrote:
"Qui si parla Campagnolo" wrote in message oups.com... Kyle.B.H. wrote: I'm having problems (again) shifting from my middle to granny under load. I just replaced my moderately worn 40t middle with a new 38t, and the problem crept up again. I have already taken the measures of filing away the portion of the derailer that conatcts the frame, filing a small groove in the seat tube itself, and even moving my chainline outward about a mm via a BB spacer, and still no success. It shifts fine when not under load, but once you start up an incline, forget it, it won't go. Its an Ultegra der. and TA Alize rings. So now I'm thinking I'll file the tops off of two consectutive teeth in the middle ring to aid the shift. Don't some chainrings include this as a feature? A) Think this will help? B) If I do this, where on the ring (relative to the right crankarm) would I file the teeth? C) Any other suggestions? Thanks, Kyle Perhaps the 6603 front der which is designed for a 39t middle ring, with the appropriate ramps to get the chain to the granny. I was under the impression that shifting the front "under load" wasn't a plan. Bill unfortunately, the need for the granny gear most often coincides with the drivetrain being under at least some load, i.e. you're going up hill. |
#5
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Qui si parla Campagnolo wrote:
Perhaps the 6603 front der which is designed for a 39t middle ring, with the appropriate ramps to get the chain to the granny. OH! Last week I got a 6603 fd and was really surprised to find that it was incompatible with my old 105 triple crank and chainrings (42t middle). Now I know why it didn't work. Thanks! |
#6
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Tim Lines wrote: Qui si parla Campagnolo wrote: Perhaps the 6603 front der which is designed for a 39t middle ring, with the appropriate ramps to get the chain to the granny. OH! Last week I got a 6603 fd and was really surprised to find that it was incompatible with my old 105 triple crank and chainrings (42t middle). Now I know why it didn't work. Thanks! Yep, we have diffuculty finding 6503 front ders, since the 6603, 7703, 7803 and probably the 105 level 10s triple, won't work well with their older triple cranks...another thanks to shimano!!! |
#7
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Qui si parla Campagnolo wrote:
Tim Lines wrote: Qui si parla Campagnolo wrote: Perhaps the 6603 front der which is designed for a 39t middle ring, with the appropriate ramps to get the chain to the granny. OH! Last week I got a 6603 fd and was really surprised to find that it was incompatible with my old 105 triple crank and chainrings (42t middle). Now I know why it didn't work. Thanks! Yep, we have diffuculty finding 6503 front ders, since the 6603, 7703, 7803 and probably the 105 level 10s triple, won't work well with their older triple cranks...another thanks to shimano!!! But Campy Mirage worked out fine, thanks. It was in my box-o-stuff so that's what I ended up with. |
#8
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Kyle.B.H. wrote:
I'm having problems (again) shifting from my middle to granny under load. I just replaced my moderately worn 40t middle with a new 38t, and the problem crept up again. I have already taken the measures of filing away the portion of the derailer that conatcts the frame, filing a small groove in the seat tube itself, and even moving my chainline outward about a mm via a BB spacer, and still no success. It shifts fine when not under load, but once you start up an incline, forget it, it won't go. Its an Ultegra der. and TA Alize rings. So now I'm thinking I'll file the tops off of two consectutive teeth in the middle ring to aid the shift. Don't some chainrings include this as a feature? A) Think this will help? B) If I do this, where on the ring (relative to the right crankarm) would I file the teeth? C) Any other suggestions? Get a longer BB spindle. |
#9
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I'm having problems (again) shifting from my middle to granny under load.
I just replaced my moderately worn 40t middle with a new 38t, and the problem crept up again. I have already taken the measures of filing away the portion of the derailer that conatcts the frame, filing a small groove in the seat tube itself, and even moving my chainline outward about a mm via a BB spacer, and still no success. It shifts fine when not under load, but once you start up an incline, forget it, it won't go. Its an Ultegra der. and TA Alize rings. The greater the gap between the largest two chainrings, the more difficulty there will be shifting from the middle to the smallest. That's an absolute fact of life, regardless of what you may read elsewhere. That doesn't mean you can't make it work better than it presently does (by using a derailleur designed for a smaller middle chainring, such as Peter/Qui si parla Campagnolo suggested). Or it might work better if you bring down the size of the largest chainring, although at some point you have the curve of the derailleur not matching up to the radius of the outer chainring, which will also cause shifting issues. With the DuraAce 9-speed triple (with 52/39/30), Shimano tried to get around this by cutting down the profile of the teeth on the middle chainring. Unfortunately, it was/is legendary for dumping the chain off the middle chainring as you're "just riding along." The shifting was terrible compared to the Ultegra 52/42/30. However, for the new Ultegra 10, they seem to have gotten their act together and the 52/39/30 shifts quite nicely. Dramatic improvement. But it also has a highly-convoluted middle chainring that would be difficult to duplicate with your dremel tool, *and* will probably wear out more quickly too. Please note these problems are exacerbated by STI shifting, which doesn't allow you to control the shifting process as much as Ergo or friction. They're also far pickier about chain choice and, I daresay, if you're using an SRAM chain, you may have better results with a Shimano. --Mike-- Chain Reaction Bicycles www.ChainReactionBicycles.com "Kyle.B.H." wrote in message ... I'm having problems (again) shifting from my middle to granny under load. I just replaced my moderately worn 40t middle with a new 38t, and the problem crept up again. I have already taken the measures of filing away the portion of the derailer that conatcts the frame, filing a small groove in the seat tube itself, and even moving my chainline outward about a mm via a BB spacer, and still no success. It shifts fine when not under load, but once you start up an incline, forget it, it won't go. Its an Ultegra der. and TA Alize rings. So now I'm thinking I'll file the tops off of two consectutive teeth in the middle ring to aid the shift. Don't some chainrings include this as a feature? A) Think this will help? B) If I do this, where on the ring (relative to the right crankarm) would I file the teeth? C) Any other suggestions? Thanks, Kyle |
#10
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On Wed, 04 May 2005 15:56:28 GMT, "Mike Jacoubowsky"
wrote: With the DuraAce 9-speed triple (with 52/39/30), Shimano tried to get around this by cutting down the profile of the teeth on the middle chainring. Unfortunately, it was/is legendary for dumping the chain off the middle chainring as you're "just riding along." The shifting was terrible compared to the Ultegra 52/42/30. However, for the new Ultegra 10, they seem to have gotten their act together and the 52/39/30 shifts quite nicely. Dramatic improvement. But it also has a highly-convoluted middle chainring that would be difficult to duplicate with your dremel tool, *and* will probably wear out more quickly too. Please note these problems are exacerbated by STI shifting, which doesn't allow you to control the shifting process as much as Ergo or friction. They're also far pickier about chain choice and, I daresay, if you're using an SRAM chain, you may have better results with a Shimano. --Mike-- Chain Reaction Bicycles www.ChainReactionBicycles.com Mike, the DA 9-speed triple 7703 has a 53t large chainring. So, you have 53/39/30. I have about 3700 miles on my DA crankset and I have never had it dump off from the middle chainring. Is this a problem that shows up with use and wear, or if it is going to be a problem, does it happen right from new? One more thing to worry about? Life is Good! Jeff |
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