Triple front derailleur tune
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Triple front derailleur tune
I write in desperation. I have been trying to fine-tune my RSX triple FD for a year. I can get it to where I get chain rub during extreme cross-chain (large-large, small-small), which I expect. However, when tuned thusly I still loose the next two cogs on the rear cassette as well (7 spd.). Meaning, my chain rubs on the smallest three cogs on the cassette when in my granny ring. I feel like this is unreasonable.
Things I have tried:
Cable tension
Limit screws
Derailleur height
Derailleur line-up with chainring
I guess what I need to know is: a. should it be possible to set this up so that I only get chainrub when cross-chaining (or not at all), and b. do you have suggestions as to how I do this? TIps? Tricks?
Or do I get a new FD?
Things I have tried:
Cable tension
Limit screws
Derailleur height
Derailleur line-up with chainring
I guess what I need to know is: a. should it be possible to set this up so that I only get chainrub when cross-chaining (or not at all), and b. do you have suggestions as to how I do this? TIps? Tricks?
Or do I get a new FD?
#2
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Somestimes you'll still get chain rub in some combinations other than just when you are in the extremes.
Honestly, i consider the granny and the hardest rear gears cross chainging. you could proabbly get a similar ratio in the middle ring and some of the lower gears.
Assuming your FD cage is straight make sure the outer cage is aligned with the outer chainring looking form the top down and that the cage is aobut 3 to 4 mm above the teeth on the outer chainring. The other thing to make sure is dialed is the lower limit screw on the FD. Usually you can dial it in so that the inner cage is within about 1 to 2 mm from the chan when the FD is in the granny and the RD is in the easiest gear. Just make sure that the chain will still shift down from the middle to the granny and you should be set.
Once you have thoes two things set up leave the FD in the granny and shift the RD to the gear that are giving you trouble in the back. if you still get rubbing theres proabbly nothing you can do without performing some type of special bend that will allow you to run the combo you want to.
Honestly, i consider the granny and the hardest rear gears cross chainging. you could proabbly get a similar ratio in the middle ring and some of the lower gears.
Assuming your FD cage is straight make sure the outer cage is aligned with the outer chainring looking form the top down and that the cage is aobut 3 to 4 mm above the teeth on the outer chainring. The other thing to make sure is dialed is the lower limit screw on the FD. Usually you can dial it in so that the inner cage is within about 1 to 2 mm from the chan when the FD is in the granny and the RD is in the easiest gear. Just make sure that the chain will still shift down from the middle to the granny and you should be set.
Once you have thoes two things set up leave the FD in the granny and shift the RD to the gear that are giving you trouble in the back. if you still get rubbing theres proabbly nothing you can do without performing some type of special bend that will allow you to run the combo you want to.
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Originally Posted by tellyho
I write in desperation. I have been trying to fine-tune my RSX triple FD for a year. I can get it to where I get chain rub during extreme cross-chain (large-large, small-small), which I expect. However, when tuned thusly I still loose the next two cogs on the rear cassette as well (7 spd.). Meaning, my chain rubs on the smallest three cogs on the cassette when in my granny ring. I feel like this is unreasonable.
Things I have tried:
Cable tension
Limit screws
Derailleur height
Derailleur line-up with chainring
I guess what I need to know is: a. should it be possible to set this up so that I only get chainrub when cross-chaining (or not at all), and b. do you have suggestions as to how I do this? TIps? Tricks?
Or do I get a new FD?
Things I have tried:
Cable tension
Limit screws
Derailleur height
Derailleur line-up with chainring
I guess what I need to know is: a. should it be possible to set this up so that I only get chainrub when cross-chaining (or not at all), and b. do you have suggestions as to how I do this? TIps? Tricks?
Or do I get a new FD?
See also: https://sheldonbrown.com/derailer-adjustment
Sheldon "Our Essex" Brown
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Originally Posted by tellyho
Meaning, my chain rubs on the smallest three cogs on the cassette when in my granny ring. I feel like this is unreasonable.
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Even if your derailers are adjusted perfectly you will still get chain rub in the most extreme cross chaining configurations. I have a triple in the front and 10 gears in the back. I used https://www.parktool.com/repair/ to setup my derailers. The also have a good section on breaks too. But when riding I don't cross chain to that extreme very often I usually run the granny gear when approching steep or very long hills. and the large chainring when approching nice downhill runs. I use the middle chainring most of the time. But check out the parktool website. After I used the setup (in order) from that site. I went for a test ride and only made a couple quarter turn adjustments and it was perfect. Don't forget, If you have a triple in the front, your front derailer probably has what is called "trim". When you shift you may feel what seems to be 4 shifting positions with only 3 gears. By using this "half shift" or "trim" on the middle chainring you won't have any chainrub when running the middle gear.
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Russ - no trim on RSX, sadly. They're base-level STI.
Sheldon - your site is, of course, invaluable. I am running the RSX gruppo, so the crank and rings should be the numbers you quoted. I haven't checked. Prior owner would not have been the person to change that up.
Retro Grouch - your point is a good one, and the answer is mostly "no". However, I feel like I should be able to use them. I am entitled to functioning gears!
Ingleside - thanks for the number reminders on FD clearance. I will check all of those.
Thanks all for the suggestions. The general impression I am getting is a mild and gently-put "suck it up". So suck I shall.
Sheldon - your site is, of course, invaluable. I am running the RSX gruppo, so the crank and rings should be the numbers you quoted. I haven't checked. Prior owner would not have been the person to change that up.
Retro Grouch - your point is a good one, and the answer is mostly "no". However, I feel like I should be able to use them. I am entitled to functioning gears!
Ingleside - thanks for the number reminders on FD clearance. I will check all of those.
Thanks all for the suggestions. The general impression I am getting is a mild and gently-put "suck it up". So suck I shall.
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I'm a bit late to this thread but there is one possible thing you should check.
Shimano front derailleurs have a little tab that sticks out on the inboard side of the cable fixing bolt at about the 8:00 or 9:00 position seen from the rear of the bike. The cable should be routed over and above this tab. It should NOT be routed between the tab and the fixing bolt. Routing the cable correctly makes a big difference.
Shimano front derailleurs have a little tab that sticks out on the inboard side of the cable fixing bolt at about the 8:00 or 9:00 position seen from the rear of the bike. The cable should be routed over and above this tab. It should NOT be routed between the tab and the fixing bolt. Routing the cable correctly makes a big difference.
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Originally Posted by tellyho
Sheldon - your site is, of course, invaluable. I am running the RSX gruppo, so the crank and rings should be the numbers you quoted. I haven't checked. Prior owner would not have been the person to change that up.
The RSX triples that I'm familliar with had great shifting performance, at least as good as Ultegra.
Al
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Originally Posted by tellyho
Thanks all for the suggestions. The general impression I am getting is a mild and gently-put "suck it up". So suck I shall.
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Originally Posted by HillRider
I'm a bit late to this thread but there is one possible thing you should check.
Shimano front derailleurs have a little tab that sticks out on the inboard side of the cable fixing bolt at about the 8:00 or 9:00 position seen from the rear of the bike. The cable should be routed over and above this tab. It should NOT be routed between the tab and the fixing bolt. Routing the cable correctly makes a big difference.
Shimano front derailleurs have a little tab that sticks out on the inboard side of the cable fixing bolt at about the 8:00 or 9:00 position seen from the rear of the bike. The cable should be routed over and above this tab. It should NOT be routed between the tab and the fixing bolt. Routing the cable correctly makes a big difference.
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Oh, I could definitely not run those combos, and am a very conscious shifter in general. But then I would be thinking "I can't use those combos, and probably never would, but dammit, I SHOULD be able to."
I like knowing that if my FD shift cable broke in the middle of a long ride while I was in the small chainring, I'd be able to use all of my cogs. And yes, I know it's ridiculous.
I like knowing that if my FD shift cable broke in the middle of a long ride while I was in the small chainring, I'd be able to use all of my cogs. And yes, I know it's ridiculous.
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Originally Posted by tellyho
Oh, I could definitely not run those combos, and am a very conscious shifter in general. But then I would be thinking "I can't use those combos, and probably never would, but dammit, I SHOULD be able to."