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SLX Front Derailleur

2K views 10 replies 4 participants last post by  dan0 
#1 ·
Hello, I just finished building my bike and the final thing I need to do is adjust the derailleurs but running into some issues and had a question. Is it normal for the chain to rub against the derailleur when the chain is either at the smallest or biggest cog in the back? When I adjust for the biggest cog and small chainring and then run down to the smallest cog it starts to rub against the right side of the front derailleur, like it's not wide enough :confused:

I'm running an SLX front derailleur and an SLX two ring crank with a SRAM cassette and X9 rear derailleur.
 
#2 ·
zx1100 said:
Hello, I just finished building my bike and the final thing I need to do is adjust the derailleurs but running into some issues and had a question. Is it normal for the chain to rub against the derailleur when the chain is either at the smallest or biggest cog in the back? When I adjust for the biggest cog and small chainring and then run down to the smallest cog it starts to rub against the right side of the front derailleur, like it's not wide enough :confused:

I'm running an SLX front derailleur and an SLX two ring crank with a SRAM cassette and X9 rear derailleur.
after you set the stops crosschain, big /big and small/ small adjust with the barrel adjuster for each one
 
#6 ·
Is it normal for the chain to rub against the derailleur when the chain is either at the smallest or biggest cog in the back? When I adjust for the biggest cog and small chainring and then run down to the smallest cog it starts to rub against the right side of the front derailleur, like it's not wide enough
It is normal to have rubbing with small chain ring in the front and small cog in the rear (cassette).
 
#9 ·
AzSpeedfreek said:
I prefer my bike to shift quickly and smoothly without droping the chain, thanks try again;) .
what does adjusting the barrel adjuster have to do with dropping your chain?

this is the procedure for adjusting your fd ( assuming its properly installed)

1. unhook cable adjust inner stop , with rear cassette in lowest (biggest)gear
2. re attach cable ( make sure your barrel adjuster is not all the way in, I like it out 2 full turns)
3. shift to biggest gear front , smallest rear
4. adjust outer stop
now
shift the cassette to the lowers(biggest) gear with the front still in the largest gear , this is called cross chaining
if the chain is rubbing on the outer or inner side of the front chain guide adjust the barrel adjuster until it stops
next
shift to the lowest gear in front and highest in back ( opposite cross chain)
if its rubbing adjust the barrel again
thats all there is to it, turning the barrel adjuster has no effect on the chain dropping off. it is just a way to fine tune the tension of the cable which will either move the fd cage in(looser) or out (tighter) once its adjusted properly it will shift smoothly and quickly
 
#10 ·
dan0 said:
what does adjusting the barrel adjuster have to do with dropping your chain?

this is the procedure for adjusting your fd ( assuming its properly installed)

1. unhook cable adjust inner stop , with rear cassette in lowest (biggest)gear
2. re attach cable ( make sure your barrel adjuster is not all the way in, I like it out 2 full turns)
3. shift to biggest gear front , smallest rear
4. adjust outer stop
now
shift the cassette to the lowers(biggest) gear with the front still in the largest gear , this is called cross chaining
if the chain is rubbing on the outer or inner side of the front chain guide adjust the barrel adjuster until it stops
next
shift to the lowest gear in front and highest in back ( opposite cross chain)
if its rubbing adjust the barrel again
thats all there is to it, turning the barrel adjuster has no effect on the chain dropping off. it is just a way to fine tune the tension of the cable which will either move the fd cage in(looser) or out (tighter) once its adjusted properly it will shift smoothly and quickly
In my expirence (and I have a lot of expirence) using those directions will in a perfect world get the job done with no noise "maybe". You need to understand that we don't live in a perfect world and that somethings don't follow the rules. Now I never said that in all situations/every time the chain will rub on the der. cage while cross chaining, I did say that it is normal however for it to rub (when cross chaining). I guess what I should add that I left out is that it is a very fine line on some bikes between shifting fast and properly and droping the chain off of the small ring. Sometimes you have to run the cage a little tighter and/or angle it in order to get it to shift properly and running it a bit tighter which will cause rubbing while cross chaining to keep the chain from droping. No two bikes are the same so saying that following those directions that you posted will result in a rub free drive train is false and misleading.
 
#11 ·
AzSpeedfreek said:
In my expirence (and I have a lot of expirence) using those directions will in a perfect world get the job done with no noise "maybe". You need to understand that we don't live in a perfect world and that somethings don't follow the rules. Now I never said that in all situations/every time the chain will rub on the der. cage while cross chaining, I did say that it is normal however for it to rub (when cross chaining). I guess what I should add that I left out is that it is a very fine line on some bikes between shifting fast and properly and droping the chain off of the small ring. Sometimes you have to run the cage a little tighter and/or angle it in order to get it to shift properly and running it a bit tighter which will cause rubbing while cross chaining to keep the chain from droping. No two bikes are the same so saying that following those directions that you posted will result in a rub free drive train is false and misleading.
you know
I missread your first post. I thought you were asking if its normal not stating it is
but I wouldnt say its normal, maybe in some circumstances but normally your chain shouldnt rub on the sides of the cage period. its way more common to have it rub on the bottom when the suspension isnt compressed. there are allways exceptions and thats where a good mechanic will show his stuff. I did say however say that all my instructions were premissed on the fd being installed correctly which would include height and angle
 
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