Need an opinion on gearing
06-11-07, 08:58 PM
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Need an opinion on gearing
I have a triple front and a 9speed cassette rear using a long arm Ultegra 10speed derailleur. I need to get a bigger sprocket like a 30T in the rear. My LBS says the biggest I can go with is 26T which I currently have. Does anyone know if I can use anything bigger than a 26T sprocket in my rear cassette? I am having trouble climbing big steep hills cause I'm not 150 lbs. I paid a lot of money for the Ultegra derailleur and want to avoid swapping it with something like a Deore RD. Any help would be appreciated.
06-11-07, 10:55 PM
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This link will tell you all you need to know about chain wrap, chain length, and appropriate RD size.
https://sheldonbrown.com/harris/derailers-rear.html
https://sheldonbrown.com/harris/derailers-rear.html
06-12-07, 04:53 AM
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This might not be what you want to hear but it's what I think that you should know.
A 30 tooth cog probably isn't going to help you all that much.
My advice is to get a 12/34 mountain bike cassette and the rear derailleur to go with it. You'll need a new, longer chain too. Save your old parts to replace when you get into better hill-climbing shape.
A 30 tooth cog probably isn't going to help you all that much.
My advice is to get a 12/34 mountain bike cassette and the rear derailleur to go with it. You'll need a new, longer chain too. Save your old parts to replace when you get into better hill-climbing shape.
06-12-07, 08:15 AM
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Originally Posted by Retro Grouch
This might not be what you want to hear but it's what I think that you should know.
A 30 tooth cog probably isn't going to help you all that much.
My advice is to get a 12/34 mountain bike cassette and the rear derailleur to go with it. You'll need a new, longer chain too. Save your old parts to replace when you get into better hill-climbing shape.
A 30 tooth cog probably isn't going to help you all that much.
My advice is to get a 12/34 mountain bike cassette and the rear derailleur to go with it. You'll need a new, longer chain too. Save your old parts to replace when you get into better hill-climbing shape.
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"c" is not a unit that measures tire width
"c" is not a unit that measures tire width
06-12-07, 08:27 AM
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You could change the smallest chainring to a 28. And you could change the cassette to a custom built 13-28 or possibly 13-30. This would give you significantly lower gearing without the big ratio jumps of a mountain type cassette and you would not have to replace the derailleur. Running a 30t large cog in the back often requires replacing the "B" screw with a longer one. Sheldon Brown offers custom 9-speed cassettes.
You could replace all of the chainrings or possibly the entire crankset with something like 50-39-28 but this may take some creative tweaking to get the shifting right, and the chainrings need to be triple specific. The 10-speed Shimano 105 triple crankset is 50-39-30.
Al
You could replace all of the chainrings or possibly the entire crankset with something like 50-39-28 but this may take some creative tweaking to get the shifting right, and the chainrings need to be triple specific. The 10-speed Shimano 105 triple crankset is 50-39-30.
Al
06-12-07, 09:16 AM
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Originally Posted by Al1943
You could change the smallest chainring to a 28. And you could change the cassette to a custom built 13-28 or possibly 13-30. This would give you significantly lower gearing without the big ratio jumps of a mountain type cassette and you would not have to replace the derailleur. Running a 30t large cog in the back often requires replacing the "B" screw with a longer one. Sheldon Brown offers custom 9-speed cassettes.
You could replace all of the chainrings or possibly the entire crankset with something like 50-39-28 but this may take some creative tweaking to get the shifting right, and the chainrings need to be triple specific. The 10-speed Shimano 105 triple crankset is 50-39-30.
Al
You could replace all of the chainrings or possibly the entire crankset with something like 50-39-28 but this may take some creative tweaking to get the shifting right, and the chainrings need to be triple specific. The 10-speed Shimano 105 triple crankset is 50-39-30.
Al
Assuming that the bike has a standard road crank on it, the bolt circle is probably a 130/74mm. A 74mm BCD will take down to a 24 tooth. I've done this on touring bike and it works okay. A 26 tooth ring might work a little better.
As for the rear derailer, a 30 tooth might work or it might not, you never know until you try. I'm a big fan of experimentation (on the work stand) before saying it won't work. Shimano's capacity numbers are very conservative.
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Plan Epsilon Around Lake Michigan in the era of Covid
Old School…When It Wasn’t Ancient bikepacking
Gold Fever Three days of dirt in Colorado
Pokin' around the Poconos A cold ride around Lake Erie
Dinosaurs in Colorado A mountain bike guide to the Purgatory Canyon dinosaur trackway
Solo Without Pie. The search for pie in the Midwest.
Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
06-12-07, 09:39 AM
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Originally Posted by cyccommute
Assuming that the bike has a standard road crank on it, the bolt circle is probably a 130/74mm. A 74mm BCD will take down to a 24 tooth. I've done this on touring bike and it works okay. A 26 tooth ring might work a little better.
As for the rear derailer, a 30 tooth might work or it might not, you never know until you try. I'm a big fan of experimentation (on the work stand) before saying it won't work. Shimano's capacity numbers are very conservative.
As for the rear derailer, a 30 tooth might work or it might not, you never know until you try. I'm a big fan of experimentation (on the work stand) before saying it won't work. Shimano's capacity numbers are very conservative.
06-12-07, 02:22 PM
#8
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What size is your small ring up front? maybe you can drop a couple teeth there?
