# Front Derailleur... I just don't get it!



## gofastgt (Feb 17, 2010)

So I've posted before about having noise when pedaling in certain gears. It's definitely the chain rubbing against the front derailleur. I have done a lot of searches on here, but wanted to post a pic of my rig for any suggestions (see below).

Adjusting the tensioner up by the handlebar helps, but I have to adjust it all the time while riding to get the noise to stop... I'm guessing this isn't right.

So now I'm thinking I need to move on to adjusting the derailleur itself. I know I have the 2 screws in the picture. Guessing I need to mess with these, right? I found this link that explains how to do it, should I follow this?: How to Adjust a Front Bicycle Derailleur: 9 steps (with pictures)

Thanks for any input!


----------



## bean. (Mar 19, 2012)

I'm just going to chime in and say I also have this problem on a bike I have. Same thing, front derailleur and everything. I've gotten it to the point where it only makes noise on gears with sort of bad chain lines (1x5, 6, 7, 8) (2x 6, 7, 8) (3x 1, 2, 3) and I did this, as the OP said, but adjusting the barrel adjuster up by the handle, but I feel like I should have more access the gears in, for example, the middle cog up front (2x) gears, rather than only having access to 1-5 on the rear set. Not hijacking the thread by any means, just saying that there would be more than one person who would appreciate an answer.


----------



## gofastgt (Feb 17, 2010)

I don't consider it hijacking at all, if more than one can benefit from the answers then all the better! I just hope there's a simple answer...


----------



## SenorSerioso (Apr 22, 2011)

Front derailleurs can be a tricky beast. I'll start by saying that when you "cross the chain" (using small-small, big-big, and similar chain lines) the chain will always rub.

In the middle ring up front (number 2) you should have access to all of your cassette (the rear cogs). If the big cassette cogs are not accessible without rubbing, the front derailleur cable is too tight. If the small rings on the cassette are not accessible without rubbing, the front derailleur cable is too loose. 

To tighten the cable, rotate the barrel on the shifter counter-clockwise. To loosen, turn clockwise. 

The two screws you see, designated by "H" (high) and "L" (low) only affect the high and low limits, how far up and down the derailleur is allowed to move in extremes. This will be unused in most situations like the problems you describe today.

Does this help?


----------



## gofastgt (Feb 17, 2010)

This does help, SensorSerioso, thank you, however I have adjusted the barrel on the shifter a lot, and can never seem to get a "no rubbing" situation when on the middle ring up front, and hitting all of the cogs out back. In this case, would I have to adjust something else?


----------



## SenorSerioso (Apr 22, 2011)

This is where it can get a tad hairy. The barrel can only be adjusted so far. Once it gets to the end of the barrel, it needs to be threaded back in and slack should be pulled out from the derailleur where the cable end is crimped. 

One thing I check when a front derailleur is giving me issues is if it is straight and properly aligned. Sometimes, especially older setups like yours, they can move a tad. This is normal but should be adjusted. Look at your middle chain ring, it's a disk that sits on a one dimensional plane. Envision this plane in your mind. Now look at the derailleurs orientation. The outer bar makes a plane as well. Is this plane parallel to the plane the chainring makes? If not the derailleur can be rotated to make it so. Pay close attention to use the proper screw to loosen the derailleur. There are two in close proximity to each other, one for the clamp, the other to secure the cable. 

It should be noted that this trick is far from a catch-all and only works with some derailleurs some of the time. 

I have actually run into some older equipment that just WILL NOT cooperate. This is even rarer than the above tip working. 

There are many more possible scenarios I'm envisioning but it's one of those things I'd just have to get my hands on to know with certainty.


----------



## crclawn (Sep 26, 2010)

Watch this video: How to Adjust a Front Derailleur - YouTube

Then do each step the mechanic tells you to do. When I was learning, I watched then paused the video and did exactly what the mechic did, then went to the next step. Easiest most clear video I've seen on how to adjust front deraillure. Like above said, crosschaining you get rub. You'll also get rub from flex too. What's funny is that when I really didn't understand how deraillures worked, chain rub drove me nuts. Now it really doesn't bother me that much. He also has a great video on how to adjust the rear deraillure. Best of luck.


----------



## gofastgt (Feb 17, 2010)

First things first - Anchorman rules!

Second, great video! Thank you for that. Good think I have a laptop, I'm bringing it out to the garage tomorrow night and going through each of the steps, that's perfect. I definitely understand that the extreme combo's will almost always rub, but if I can at least get the middle gear up front to not rub regardless of what gear I'm on in the back, I'll be a happy camper!

Thanks again Ron..... uh, crclawn!


----------



## roblee (Sep 26, 2011)

If you have trigger shifters you have to precisely dial in the adjustments,sometimes even slightly widening the cage.
I just set up my bike with triggers and to stop rub in extreme chain angles I had to slightly widen the derailleur cage just enough so it just barely clears.Still shifts great though.
If you have grip or twist shifters you can trim the derailleur on the fly as you ride with a twist of the shifter.One reason I love twist shifting,you can set that derailleur where ever you want as you ride.


----------



## winter (Nov 30, 2009)

Assuming [you know what they say about assume...makes an a$$ out of u and me] your shifter is working properly, the cables and housing are not gunked up, the chain width is appropriate for the drivetrain, the chain line is correct, the front rings are not bent or loose, the bottom bracket is not wobbly, and the front derailleur is moving smoothly without a bent cage, then it should be possible to adjust the front derailleur such that you can shift across the entire cassette while in any ring, without the chain rubbing on the FD's cage.

I read the page you linked and agree with most of the step by step directions that the author proposed. There are nuances to front derailleur adjustment that's hard to describe in words, but let's use the page you linked as a common frame of reference.

Steps 1 through 4. With the derailleur cable detached and the chain on the small ring, are you able to use the L limiter screw to adjust the FD such that the chain does not rub either side of the cage when shifting across the entire rear cassette? Do not proceed further until you can do so. Some finer nuances...adjust the L limiter screw such that it favors the inner side of the cage; i.e. the chain almost rubs the outer bar of the cage when going from small ring to smallest cog, this will leave plenty of room between the chain and the inner bar of the cage when the chain goes from small ring to largest cog. More finer nuances...if your chain line is slightly off, it might be necessary to loosen the derailleur clamp band and rotate the derailleur such that the cage is not parallel with the front rings; to determine if your chain line is off, take a straight edge and lay it flat against the middle ring, the straight edge should intersect the rear cassette in the middle. If the straight edge points to the larger cogs, then the derailleur should angle slightly outwards such that the cage points toward the outside; conversely, if the straight edge points to the smaller cogs, then the derailleur should angle slightly to the inside.

Step 5. With the cable detached, place the chain on the largest ring and smallest cog; adjust the H limiter screw such that when you push the cage as far as it will go, there is still about 1 mm of gap between the chain and the outer bar of the cage. Finer nuance...the 1mm gap between the chain and the outer bar of the derailleur cage is not absolute; the key is to adjust the limiter screw such that when shifting from middle to large ring, there's enough derailleur cage throw to push the chain up to the big ring and at the same time does not overshift and push it off the big ring onto the crank arm.

Step 6. I agree with the author, let the derailleur's spring shift the chain down to the smallest ring by itself.

Step 7. Before pulling the cable tight and tightening the cinch bolt, turn your barrel adjuster so that it's about half way between the extremes, this way, you'll be able to make adjustments in either direction to increase or decrease tension as needed. Make sure you release all the tension in the shifter (i.e. shift to the smallest ring) before tightening the bolt. Finer nuance...my fingers cannot pull the cable to eliminate all the tension before tightening it down; I use a pair of small locking pliers to pull the cable and would encourage you to use a similar tool to pull the cable tight.

Step 8a. Now use your barrel adjuster for fine adjustments. Leave the chain in the small ring and shift across the entire rear cassette, there should be no rub against the cage if you performed steps 1 to 4 correctly. Now shift the chain to the middle ring and shift the rear derailleur across the entire cassette, adjust the front shifter's barrel adjuster so there's no rub. Do likewise for the large ring. An important point to keep in mind...if you're working without a bike stand and your bike is upside down, do not mix up left and right; I've made adjustments to barrel adjusters without any results and only later realized that I was adjusting the rear cable when I meant to adjust the front cable and vice versa. Finer nuances...do not turn the barrel adjuster more than 1/4 turn or one click at a time; after each 1/4 rotation, shift the cable through it's entire range of motion to release any stiction as tiny releases or increase in tension might not show up if the cable is sticking slightly in the housing.

Step 8b. If the chain overshifts the small ring and falls on the bottom bracket housing, then tighten the L limiter screw slightly.

Good luck!


----------



## zebrahum (Jun 29, 2005)

gofastgt said:


> ...but if I can at least get the middle gear up front to not rub regardless of what gear I'm on in the back, I'll be a happy camper!


Probably won't happen. Very few bikes are able to be adjusted such that there is absolutely no rub in all gear positions in the rear. I usually set it up so that it is faintly or not rubbing in 2-1 and just deal with whatever happens in 2-9.

I suspect you can improve your odds by adjusting the angle of the cage and making sure that the cage isn't deformed. You could also try bending the two sides of the cage a bit so that the opening between is larger, but that can affect shifting so only make small adjustments that you can reverse if necessary. Sometimes I have found that I need to angle the cage so that it is no longer parallel to the rings (by a tiny amount) in order to get more gear range without rubbing.

I think you need to ride rougher trails so you don't hear your drivetrain!


----------



## Caffeine Powered (Mar 31, 2005)

I have four suggestions:

-follow a video and tune it yourself
-when you fail, take it to a bike shop and have them tune it
-remove the derailleur and shifter and go 1x
-remove both the shifters and derailleurs and go single speed.

I can guarantee you'll need to bother us less about derailleur rubbing if you go singlespeed.


----------



## Paul.C (Aug 13, 2011)

SS is not the answer here. I say tune your derailleur and when you fail try again and again and again. That is how I learned. Now I can diagnose a FD issue as it occurs. I will say that going 1x or SS would also help depending on your riding style and terrain.


----------



## pryorflstf (Feb 22, 2012)

If you have followed all the steps and video's above and you still get some rub, your probably "cross-chaining" and there is a better combo that will be easier on your drive train. A good rule of thumb is, depending on your setup, little cog in front 1-3 in back, middle cog up front 4-6 in back, big ring up front 7-9,10 in back. Not saying you can't use different combo's but the reason for the rub is the angle of your chain making it work at an angle that will wear it and your gears prematurely. I just leaned this myself riding a POS with a freewheel gear set doesn't help either.


----------



## James_spec (Jul 28, 2011)

First adjust your inner and outer screw limits correctly to prevent your chain from falling off either end. Then turn the barrel adjuster to tighten or loosen cable tension to the front derailleur. If it's too loose the derailleur won't move far enough to shift to the next gear. Too tight and the shift lever will be stiff and move the derailleur too far. At least this is what i learned from messing with mine. Hope it helps.


----------



## jeffscott (May 10, 2006)

gofastgt said:


> So I've posted before about having noise when pedaling in certain gears. It's definitely the chain rubbing against the front derailleur. I have done a lot of searches on here, but wanted to post a pic of my rig for any suggestions (see below).
> 
> Adjusting the tensioner up by the handlebar helps, but I have to adjust it all the time while riding to get the noise to stop... I'm guessing this isn't right.
> 
> ...


So step one

Set the FD straight and parrellel to the bike (very important)...

Then set the height of the FD so when the outside plate of the FD is over the big ring there is about a 1 mm gap...

BTW you have to do both at once (not so easy).

So then you adjust the limit screws....

Then you adjust the cable tension....

If everything is good you are done...

But if it rubs on the work stand take a close look at the shifter bumps on the FD....see when and where they rub....

Sometimes the FD needs to be at a small angle to the axis of the bike because of chainline issues etc...

Okay so if it works on the stand and not when riding...check the BB for play often that is enough to cause rubbing.


----------



## gofastgt (Feb 17, 2010)

I just wanted to chime in and say thank you very much to everyone. There is some awesome info here and I need to find time to bring this all with me to the garage and play around. Work has not let me do that (although I HAVE been riding every day... don't worry  ) and should be able to get out there soon.

Thank you all, I think I have a VERY solid route I need to take here... just need to find time to get wrenching!


----------



## crclawn (Sep 26, 2010)

> although I HAVE been riding every day...


Me too! I'm tellin you man, once you really understand how the deraillure system works, rub won't bother you as much.


----------



## hashey (Jul 26, 2011)

I had a similar issue and I had tried messing with the limit screws as well, but this wasn't it. Since my chain rub was occurring on the sides of my chain/front dérailleur, I needed to pull the slack through the derailleur itself to get it back to where it was supposed to be. Then it was able to be fine-tuned up on the shifter lever. 

This occurred to me because my bike is really new yet and the cables had probably stretched a bit, but it sounds like you may need to do the same thing.


----------



## jesterz99 (Sep 22, 2010)

Change to a 1x9 and throw away that derailluer


----------



## pamt (May 28, 2009)

Great information here and OP don't get discouraged as the FD is arguably one the hardest adjustments to master and with some can be almost witchcraft. Also on some frame geometry's and FD setups you may never be able to completely eliminated all the chain rub entirely. Sram in particular can be really contrary at times.


----------



## willsbma (Mar 19, 2012)

I just discovered my outer chain ring (3x) was slightly bent and that it was causing intermittent rubbing. Now looking for a good chain ring replacement. Check yours and see if it moves slightly when pedaling


----------



## dirtdonk (Jan 31, 2004)

Your chain should absolutely not rub the derailleur. Even at crossover extremes. If you can't get it to stop by following the instructions shown here find a good mechanic.With a good mechanic he/she can do a little tweeking here and there and get it squared away. The key word being a very experienced mechanic. I'm assuming this is a decent quality bike and components. I built up an intense a few years ago and couldn't get the chain rub to go away to save my life. Watching a friend/ mechanic tweek and eyeball, tweek and eyeball five or six times was humbling and impressive and I've straightened plenty of derailleurs. That was with a new derailleur btw.


----------



## SenorSerioso (Apr 22, 2011)

dirtdonk said:


> Your chain should absolutely not rub the derailleur. Even at crossover extremes. If you can't get it to stop by following the instructions shown here find a good mechanic.With a good mechanic he/she can do a little tweeking here and there and get it squared away. The key word being a very experienced mechanic. I'm assuming this is a decent quality bike and components. I built up an intense a few years ago and couldn't get the chain rub to go away to save my life. Watching a friend/ mechanic tweek and eyeball, tweek and eyeball five or six times was humbling and impressive and I've straightened plenty of derailleurs. That was with a new derailleur btw.


I'd be willing to bet my brand new bike that this is not a frequent occurrence. I'm not the most seasoned mechanic but I can tell you that this is simply not true.


----------



## gofastgt (Feb 17, 2010)

I STILL have not had a chance to get out to the garage and tinker... so for now, I have turned up the iPod and it has worked wonders! I'll get out there soon. Thanks again for all of the thoughts! I'll post here if I come across anything that others would benefit from when searching.


----------



## locknload223 (Mar 23, 2012)

Just finished a frame swap and got the RD dialed in perfect. The front... not so much. I finally gave up and took it to my LBS. All better now. I'll learn how to do it, just wanted to get it running. So yeah, I feel your pain. You'd thing the RD would be harder.


----------



## dirtdonk (Jan 31, 2004)

SenorSerioso said:


> I'd be willing to bet my brand new bike that this is not a frequent occurrence. I'm not the most seasoned mechanic but I can tell you that this is simply not true.


What portion is simply not true.

And no, I'm not interested in your wally world bike


----------



## danpass (Apr 1, 2012)

I stopped by the lbs after a ride due to chain rubbing like the op's.

The mech said I had my choice of adjusting for the middle and small rings or the middle and large rings.

He recommended the middle and large rings so that's what I went with. He made the adjustment directly at the front derailleur.

(7 speed)


----------



## SenorSerioso (Apr 22, 2011)

dirtdonk said:


> Your chain should absolutely not rub the derailleur. *Even at crossover extremes.*


This part. Can you post a video of your bike in a repair stand with no rubbing on both big rings, please?


----------



## ghettocop (Jul 26, 2011)

Twisters..... end of problem forever.


----------



## pamt (May 28, 2009)

SenorSerioso said:


> This part. Can you post a video of your bike in a repair stand with no rubbing on both big rings, please?


+1 I would love to see that to


----------



## davecheng (Apr 6, 2012)

I think I've resigned myself to the fact that even (supposedly) proper setups on high end groups will rub when cross-chaining. The 2x10 Ultegra 6700 group on my road bike does it. And so the 2x10 SRAM X9 group on my mountain bike.

The rub-free setup it a utopian dream. Either that, or Di2.


----------



## svender (Jul 30, 2015)

SenorSerioso said:


> Front derailleurs can be a tricky beast. I'll start by saying that when you "cross the chain" (using small-small, big-big, and similar chain lines) the chain will always rub.
> 
> *In the middle ring up front (number 2) you should have access to all of your cassette (the rear cogs). If the big cassette cogs are not accessible without rubbing, the front derailleur cable is too tight. If the small rings on the cassette are not accessible without rubbing, the front derailleur cable is too loose.
> 
> ...


This solved my problem! New 9 speed Deore crankset and the rest 8 speed. I had the work done by my LBS. The middle chainring was rubbing - speeds 7 & 8. Also 8 on the large. A half dozen twist counterclockwise on the left shifter barrel and it shifts perfectly! I guess my mechanic was in a hurry so this saved me a trip back.


----------



## Rency (Sep 14, 2017)

"In the middle ring up front (number 2) you should have access to all of your cassette (the rear cogs). If the big cassette cogs are not accessible without rubbing, the front derailleur cable is too tight. If the small rings on the cassette are not accessible without rubbing, the front derailleur cable is too loose. 

To tighten the cable, rotate the barrel on the shifter counter-clockwise. To loosen, turn clockwise. "

Thanks SenorSerioso. What a help ! My issue with chain rubbing is solved. Thanks.


----------



## chazpat (Sep 23, 2006)

Rency said:


> "In the middle ring up front (number 2) you should have access to all of your cassette (the rear cogs). If the big cassette cogs are not accessible without rubbing, the front derailleur cable is too tight. If the small rings on the cassette are not accessible without rubbing, the front derailleur cable is too loose.
> 
> To tighten the cable, rotate the barrel on the shifter counter-clockwise. To loosen, turn clockwise. "
> 
> Thanks SenorSerioso. What a help ! My issue with chain rubbing is solved. Thanks.


Glad it helped you, but since he posted that 5 years ago, I'm not sure he'll get your reply!


----------

