I hope someone can help me with this problem. I just got finished reassembling my bike (took it completely apart other than bottom bracket and headset for a nice cleaning) and now that everything is together I am getting chain rub on the front derailleur (on the outer part of the derailleur cage) when the chain is in the big ring up front and the 3 smallest cogs in the rear. This happens when I am standing or sitting and putting lots of power in to the right pedal in the 2 o’clock position.
It’s hard to simulate while not riding, but when I apply force to the crank (9-speed campagnolo Record) I can see the crank flexing a bid and pushing the chain into the front derailleur cage. Is the crank flexing or the frame? This didn’t happen before I re-built it, so I’m pretty sure it’s an adjustment issue.
I consider myself a pretty good amateur bike mechanic and tried adjusting the high position on the front derailleur to give it room to flex without rubbing, but for it to stop, I have to compensate much too much and the cage rubs on the cranks very time it comes around. I also played with the angle of the cage a little, but that didn’t seem to help much either.
I’m thinking that maybe the derailleur is too high or too low on the seat tube. Please help.
I hope someone can help me with this problem. I just got finished reassembling my bike (took it completely apart other than bottom bracket and headset for a nice cleaning) and now that everything is together I am getting chain rub on the front derailleur (on the outer part of the derailleur cage) when the chain is in the big ring up front and the 3 smallest cogs in the rear. This happens when I am standing or sitting and putting lots of power in to the right pedal in the 2 oâ?Tclock position.
Itâ?Ts hard to simulate while not riding, but when I apply force to the crank (9-speed campagnolo Record) I can see the crank flexing a bid and pushing the chain into the front derailleur cage. Is the crank flexing or the frame? This didnâ?Tt happen before I re-built it, so Iâ?Tm pretty sure itâ?Ts an adjustment issue.
Cranks do flex. Your's is probably flexing no more than it was before.
Quoted message said:
I consider myself a pretty good amateur bike mechanic and tried adjusting the high position on the front derailleur to give it room to flex without rubbing, but for it to stop, I have to compensate much too much and the cage rubs on the cranks very time it comes around. I also played with the angle of the cage a little, but that didnâ?Tt seem to help much either.
That usually would do the trick.
Quoted message said:
Iâ?Tm thinking that maybe the derailleur is too high or too low on the seat tube. Please help.
Set it as low as you dare. You don't need more than 1 mm of clearance, if that.
On Thu, 12 May 2005 00:04:46 +0000 (UTC), [email hidden]
(Stefano Maranzana) said:
I hope someone can help me with this problem. I just got finished reassembling my bike (took it completely apart other than bottom bracket and headset for a nice cleaning) and now that everything is together I am getting chain rub on the front derailleur (on the outer part of the derailleur cage) when the chain is in the big ring up front and the 3 smallest cogs in the rear. This happens when I am standing or sitting and putting lots of power in to the right pedal in the 2 o’clock position.
It’s hard to simulate while not riding, but when I apply force to the crank (9-speed campagnolo Record) I can see the crank flexing a bid and pushing the chain into the front derailleur cage. Is the crank flexing or the frame? This didn’t happen before I re-built it, so I’m pretty sure it’s an adjustment issue.
I consider myself a pretty good amateur bike mechanic and tried adjusting the high position on the front derailleur to give it room to flex without rubbing, but for it to stop, I have to compensate much too much and the cage rubs on the cranks very time it comes around. I also played with the angle of the cage a little, but that didn’t seem to help much either.
I’m thinking that maybe the derailleur is too high or too low on the seat tube. Please help.
First question, are you sure the right crank is installed properly and the crank bolt torqued sufficiently?
Thank you both for the advice. I will start with the crank and then fiddle with the derailleur height and angle again.
Thanks again.
In article <[email hidden]>,
John Everett said:
On Thu, 12 May 2005 00:04:46 +0000 (UTC), [email hidden]
(Stefano Maranzana) said:
I hope someone can help me with this problem. I just got finished reassembling my bike (took it completely apart other than bottom bracket and headset for a nice cleaning) and now that everything is together I am getting chain rub on the front derailleur (on the outer part of the derailleur cage) when the chain is in the big ring up front and the 3 smallest cogs in the rear. This happens when I am standing or sitting and putting lots of power in to the right pedal in the 2 o’clock position.
It’s hard to simulate while not riding, but when I apply force to the crank (9-speed campagnolo Record) I can see the crank flexing a bid and pushing the chain into the front derailleur cage. Is the crank flexing or the frame? This didn’t happen before I re-built it, so I’m pretty sure it’s an adjustment issue.
I consider myself a pretty good amateur bike mechanic and tried adjusting the high position on the front derailleur to give it room to flex without rubbing, but for it to stop, I have to compensate much too much and the cage rubs on the cranks very time it comes around. I also played with the angle of the cage a little, but that didn’t seem to help much either.
I’m thinking that maybe the derailleur is too high or too low on the seat tube. Please help.
First question, are you sure the right crank is installed properly and the crank bolt torqued sufficiently?
On Thu, 12 May 2005 23:41:46 +0000 (UTC), [email hidden] (Stefano
Maranzana) said:
Thank you both for the advice. I will start with the crank and then fiddle with the derailleur height and angle again.
I was reading this thread hoping for advice for myself. Don't presently have a shifting problem, but find getting a FD adjusted with index shifting is a fussy and tedious thing.
Ron
Quoted message said:
In article <[email hidden]>,
John Everett said:
On Thu, 12 May 2005 00:04:46 +0000 (UTC), [email hidden]
(Stefano Maranzana) said:
I hope someone can help me with this problem. I just got finished reassembling my bike (took it completely apart other than bottom bracket and headset for a nice cleaning) and now that everything is together I am getting chain rub on the front derailleur (on the outer part of the derailleur cage) when the chain is in the big ring up front and the 3 smallest cogs in the rear. This happens when I am standing or sitting and putting lots of power in to the right pedal in the 2 o’clock position.
It’s hard to simulate while not riding, but when I apply force to the crank (9-speed campagnolo Record) I can see the crank flexing a bid and pushing the chain into the front derailleur cage. Is the crank flexing or the frame? This didn’t happen before I re-built it, so I’m pretty sure it’s an adjustment issue.
I consider myself a pretty good amateur bike mechanic and tried adjusting the high position on the front derailleur to give it room to flex without rubbing, but for it to stop, I have to compensate much too much and the cage rubs on the cranks very time it comes around. I also played with the angle of the cage a little, but that didn’t seem to help much either.
I’m thinking that maybe the derailleur is too high or too low on the seat tube. Please help.
First question, are you sure the right crank is installed properly and the crank bolt torqued sufficiently?
