bomgd3

Hi everyone
I bought my first road bike about 2 weeks ago. One issue I had is that the bike makes a grinding/rattling noise in higher gears on the right side pedal downstroke. It's loud and annoying. I think it's the chain rubbing against the front derailleur. I bought the bike from Eastern Mountain Sports, and the young-ish mechanic dude there said he would try to fix the noise but that he couldn't promise anything because many bikes will have this noise. Is chain-on-front-derailleur rubbing a common issue that just needs to be lived with, or is it fixable? I was a little dubious about the mechanic's "can't-do" attitude.

Slackerprince

Probably "cross-chaining."
Read-up on front derailleur "trim."

S

bomgd3

Thanks, just read the Sheldon Brown article and learned a good deal. I'm debating whether to (1) return the bike to EMS and buy a more expensive bike from LBS to get better service or (2) forget EMS altogether and learn to work on the bike myself. I do most of the work on my own car so obviously I'm leaning towards (2)...

Slackerprince

Talk to the manager at EMS and explain your situation.
You may not even be in a position to do a return.


S

coasting 

i adjusted my fd carefully and i get fd rubbing only on the 2 smallest rear cogs with the small chainring and the largest 2 rear cogs with the large chainring.

Slackerprince

About right.
Not sure it's possible to avoid rubbing completely.
I did have a FD a while back that had 2 trim positions, and it worked well.

S

coasting 

with the trim positions, i can get it to not rub except on the most extreme cogs. i just don'y bother using it because thre is no need to get that far on the cogs. i just use the front gears.

kleng

It's all about correct adjustment and cable tension, see this video at 9.35 minutes

https://vimeo.com/5780736

also derailleur angle can also reduce rub, so you can angle it slightly to remove rub, which is usually happening at the front of the cage. I try and align the front of the cage so it's parrallel to the chainrings and let the rear of the cage stick out a bit.

banerjek

Learn to work on the bike. It should be possible to adjust it in such a way that it shifts accurately while making no noise. Getting it just right can take some doing. As kleng mentions, you may need to play with the angle. It's not hard.

jmX

If you can tinker on cars you can certainly service a bike. These are extremely simple machines and unless you're all thumbs I can't think of a single reason the bike ever needs to see the LBS again aside from warranty issues.

A few twists of the adjuster or tweaking the FD angle will solve your problem. You'll get better over the years, so be patient at the start.

Homebrew01

parktool.com has a good repair section for all parts of the bike. Good overall resource.

bobones

With a compact chainset, you often get rubbing of the chain against the chain ring (not the derailleur cage) when in small ring at the front and small cogs at the back. There isn't much you can do about it except go up to the big ring and avoid that combo. Other rubbing can be avoided by careful alignment of the FD and use of trim.

aaronmcd

I have a compact 10 speed, and get no rubbing in any of the 20 combinations.

vasuvius

depends on the component combination
I have Ultegra components - brifters, rear sprocket, chain, both derailleurs but the chain rings are FSA. There is a very audible chain rub sound of the chain rubbing the chain ring when front/back are crossed. There is no derailleur rub at all.
my super picky mechanic tells me that only way to get rid of that is to get Ultegra crankset to have the same componentry for the entire drive train
I'm not entirely certain it's worth the $300 upgrade.

Doc V

I have Ultegra brifters and RD, 105 FD and cassette, and FSA Gossamer Pro Compact chainrings with no chain rub noise of the chain rubbing on the chainrings or FD. It took adjusting the FD 4 times to achieve this. On the cross chaining combinations the trim takes care of the noise. It all came down to getting the cable tension tweaked properly. I would encourage you to learn to tune your own derailleurs and brakes.

Bontrager

+1 on park tools website. Learn to adjust everything yourself - then you'll know it's done right and you'll never be stranded.

Duane Behrens

Same here. In the end and after numerous tries, it boiled down to proper adjustment of initial cable tension. Especially frustrating on a triple chainring setup. But once you get it, it lasts for a very long time. If you don't like videos, here is an excellent text-type tutorial. I still skim it before installing and adjusting a new front derailleur.

https://www.bicyclechainrings.com/adjustments.html

I believe most articles and videos on FD adjustment assume you've already got your rear derailleur into perfect adjustment. Also, if you go through the suggested steps and it still isn't operating noiselessly, just start over (hard as that is). Maybe even come back the next morning. You'll get it.

cyclezen

OP, as others have noted, proper Cable tension/setting is needed for the FD to have the proper alignment and for the 'trim' feature to function well. Additionally, improper angled alignment of the FD can cause rubbing and as importantly, misshifting.
If the rubbing is 'periodic', while pedaling, then a number of things could be causing this (alone or in conjunction) - 1. depending on crankset/BB it may need better adjustment 2. slightly bent chainrings 3. improper chainline 4. again, cable tension setting.
You might want to let everyone know what bike/crankset-BB, 'make' of cranks/BB, front ring sizes & cassette range you have.

Bobones has a very valid point, and this is not uncommon.
Can be more a problem with bikes of steel and Alu, for which the BB shell is 'faced' after constuction. Too much facing - whether needed or not, can make the shell undersize in width and even a undersize of 1+ mm can affect crank/ring position in the chainline.
And a 50/34 may rub, where a 50/36 may not.
If a carbon bike (or other material which is not 'faced') is properly laid-up the chainline should remain as spec'd and have less issues.
But still, a single step cassette in the small cogs can have the chain rubbing the front ring when chain is on the inside ring and on the 2 outside cogs.
Fixing the chainline can help this, but may not be enough.
When I first started using a compact, about 9 yrs ago, I had it on my Marin Treviso (steel) which was 'faced' by a real butcher - nothing I could do, I got the frame that way. The BB shell was very under-width and needed a 1.5 mm spacer under the cups to get it close to chainline center. But with my single step, I was still getting rubbage on the 3rd cog in. So I shimmed the front ring with .5 mm shims between front ring and arms (thin nylon washer at ring bolts...).
Works fine - have well over 20K mi on this setup now... and ride it almost daily, under the week. But I'm not crazy about 'compact'... I had 3 others set with compact and this one is now the only one, all rest went back to STD cranks.
I've seen better than 1/2 dozen off-the-rack 'better' bikes which rub at least on the 2nd cog, a few on the 3rd... And quite a few 'self-built' from others which also rub...
Again, quality carbon frames don;t seem to have that happen since the BB width is set very precisely. But I've also noted that quite a few carbon bikes are set with the compact crankset/rings set 'outside' the chainline center - maybe so they don;t rub ???
Manus don;t care if you crosschain, they sell more stuff...

Doc V

A website I use when adjusting derailleurs is https://www.williambenedict.com/bikes/derailleurs.html, because it specifically instructs you on when to set the cable tension and on using the barrel adjusters.