Front Derailleur

frusso said:

When I'm in my 53 tooth front chain ring and 17 in the rear my chain starts to rub the front derailleur cage. I need to move the front derailleur inword a little. what adjustment would I use? All gears shift great.

Thank you
Frank

How about using the front shifter to trim the FD?

boudreaux said:

How about using the front shifter to trim the FD?

I have STI shifters and do not have that little click. On my TT bike I have bar end shifters and I'm able to trim.

thanks

frusso said:

I have STI shifters and do not have that little click. On my TT bike I have bar end shifters and I'm able to trim.

thanks

That's why indexed front shifting is a bad idea. IMO...

meehs said:

That's why indexed front shifting is a bad idea. IMO...

Why is that a bad idea when millions of bikes have STI shifters? I guess there all wrong and I guess due to may lack of knowage I'll have to take my bike to a shop and get the FD adjusted. It's a 10 second adjustment.

Adjusted

You probably just have it aligned wrong. Play with the little screw, and cable tension until you get it right.

Go to parktools.com and look at the f derailleur adjustment proceedure. It's a simple limit screw, 10 sec.

I agree fwiw that indexed front is not a terribly great idea. Not sure what advantage a 2x or 3x index really gives, but not being able to trim properly is just plain annoying.

frusso said:

Why is that a bad idea when millions of bikes have STI shifters? I guess there all wrong and I guess due to may lack of knowage I'll have to take my bike to a shop and get the FD adjusted. It's a 10 second adjustment.

Adjusted

The reason I don't like it is because you can't trim the front derailleur (on the cheaper groups, there are only two FD positions). When the chain rubs there's nothing you can do about it. Lame. Don't pay too much for that FD adjustment.

frusso said:

I have STI shifters and do not have that little click. On my TT bike I have bar end shifters and I'm able to trim.

thanks

I bet you do(but not if the front is a 7 or 8 speed tiple) if they are adjusted right and you know how to use it.

meehs said:

The reason I don't like it is because you can't trim the front derailleur (on the cheaper groups, there are only two FD positions). When the chain rubs there's nothing you can do about it. Lame. Don't pay too much for that FD adjustment.

That's just hooey. Current STI have trim. The only ones that didn't were the 7 and 8 s speed triple fronts.And even that ws not typically an issue if things were setup right and one avoided crossover in the big and small rings.

RC2 said:

Go to parktools.com and look at the f derailleur adjustment proceedure. It's a simple limit screw, 10 sec.

I agree fwiw that indexed front is not a terribly great idea. Not sure what advantage a 2x or 3x index really gives, but not being able to trim properly is just plain annoying.

There is alot more to it than limit screws, and 10 seconds.

sparknote_s said:

You probably just have it aligned wrong. Play with the little screw, and cable tension until you get it right.

Mindless fiddling usually just makes it worse.

boudreaux said:

There is alot more to it than limit screws, and 10 seconds.

...umm, he didn't post enough information to make this clear. But if all the gears are shifting perfectly except for a bit of rub in the large chainring with the chain on the inside of the cog, it's probably the limit setting on the outside...too far out. Probably a small turn on the limit screw, assuming the rest of the shifting is really true. Of course there are a lot of more complex issues that could be going on with derailleur height/angle. But if your car won't start, check the battery first before looking for monkeys and elephants.

boudreaux said:

That's just hooey. Current STI have trim. The only ones that didn't were the 7 and 8 s speed triple fronts.And even that ws not typically an issue if things were setup right and one avoided crossover in the big and small rings.

Yeah, I guess the ones I was thinking of were "older" 8 spd MTB groups. I had friends who had them on their mountain bikes and they stunk. No trim. From my experience you could have some rubbing at the extremes even when they were adjusted properly. But thanks for clarifying the "hooey" in my post. You're good for that anyway.

meehs said:

Yeah, I guess the ones I was thinking of were "older" 8 spd MTB groups. I had friends who had them on their mountain bikes and they stunk. No trim. From my experience you could have some rubbing at the extremes even when they were adjusted properly. But thanks for clarifying the "hooey" in my post. You're good for that anyway.

The poster mentioned a 53 ring,so it's a pretty sure bet the reference was not to cheap MTB stuff. Extremes are easily avoided,and derailer rub is also influenced by other variables like chainstay length and chainline. It's not a perfect world and index front shifting is not universally bad. People should simpy pay more attention to proper usage, and the limitations of what they might have.

boudreaux said:

The poster mentioned a 53 ring,so it's a pretty sure bet the reference was not to cheap MTB stuff. Extremes are easily avoided,and derailer rub is also influenced by other variables like chainstay length and chainline. It's not a perfect world and index front shifting is not universally bad. People should simpy pay more attention to proper usage, and the limitations of what they might have.

Good points. Can't argue with you boudreaux. As usual.