Shimano fd-m191 front derailleur adjusting height and angle

[erdem]

for the first time i tried to adjust front derailleur. at first glance i tried to adjust front derailleur's height and angle. and to adjust i loosen the clamp. but in my opinion gear cable's tension was high which was still connected. i tried to increase derailleur's height by waggling and at the same time pushing up. so that there is a few mm between the bottom of the derailleur cage and largest sprocket teeth. but because of fd's inner cable tension i think i couldn't move it up enough and accidentally rub out frame's paint .. after that i tried different variations. first decreased fd's inner cable tension a bit, loosen the cable tension bolt. but i couldn't succeed in adjusting front derailleur's height and angle. should i decrease cable's tension or completely loosen the cable tension bolt when adjusting fd's height and angle ?

after trying i found a installation guide:

http://techdocs.shimano.com/media/techdocs/content/cycle/SI/SI_6R3FA_002/SI-6R3FA-002-ENG_v1_m56577569830673558.pdf

and there is a part 'SIS adjustment'. what does SIS means? and it says 'First remove the Pro-Set alignment block.' i couldn't understand this part. i haven't tried this guide yet.

any help would be appreciated ..

thanks..

[DaveM]

You should detach the cable before you move the FD around. It will be easier and you're probably going to have to readjust the cable anyway. The normal position for a FD is a couple mm above the biggest chainring with the outside of the cage parallel to the chainring.

[erdem]

(07-19-2010, 11:15 AM)DaveM Wrote:  You should detach the cable before you move the FD around.

i see. that was the biggest mistake which i made when adjusting FD ..

(07-19-2010, 11:15 AM)DaveM Wrote:  It will be easier and you're probably going to have to readjust the cable anyway.

after tightening the positioning clamp to readjust cable tension will i need a cable puller. because i don't have one. i have only pincers. will it be sufficient to tighten the cable.

before connecting gear cable i think i should move the adjusting barrel to in (tighten) for maximum amount of adjustibility.

and how do we know whether we have correct cable tension? so that shifting occurs on front gears somehow.

(07-19-2010, 11:15 AM)DaveM Wrote:  The normal position for a FD is a couple mm above the biggest chainring with the outside of the cage parallel to the chainring.

when viewing from a top view. is it means the cage is exactly above and parallel to the biggest chainring. and there is a few mm gap between them. when adjusting position of FD should i use low or high adjustment screws?

thank for these useful information. then let's give it a try

[erdem]

(07-19-2010, 01:09 PM)erdem Wrote:  after tightening the positioning clamp to readjust cable tension will i need a cable puller. because i don't have one. i have only pincers. will it be sufficient to tighten the cable.

ok. i tightened the positioning clamp and tried to adjust cable tension without a cable puller. it shifts one up gear (large cog) (i.e. 2 to 3) but doesn't shift high gear to low gear. (ie 3 to 2) what may be the problem? isn't the cable tension enough.

[DaveM]

You may actually have too much tension. Try watching this: http://bikeride.com/adjust-front-derailer/

[erdem]

thank you. i'll check cable tension again.

may be i watched this video 15-20 times. but practically can't figure out everything.

according to this documents my high adjustment screw is in the frame side and there is low adjustment screw near it. like that : h - l

according to documents it says:

if there is interference between the chain and the front derailleur inner plate at the largest chainring. tighten the top adjustment screw clockwise (about 1/8 turn).

if we tighten the TAS clockwise shouldn't it supposed to move the FD from right to left (towards the frame) so FD's inner plate will make more pressure on chain.

when i tighten LAS (low adjustment screw) clockwise it moves the FD out (as it supposed to be) and if i loose anti clockwise it moves the FD in. but whether i tighten or loosen the TAS screw it makes nothing. it doesn't change FD's position. but i didn't change chain position when trying this. i am a newbie so i can't figure out whether it is the expected behavior or whether there is a problem with top adjustment screw..

[DaveM]

(07-19-2010, 06:44 PM)erdem Wrote:  
if there is interference between the chain and the front derailleur inner plate at the largest chainring. tighten the top adjustment screw clockwise (about 1/8 turn).

This does sound backwards, but since it is quoted out of context, I can't be sure what they're trying to say.

I think you may be overthinking how this works. The two limit screws are just stops that prevent the derailleur from moving beyond a certain point. The inner one stops the der from going in so far that the chain falls off to the inside. The outer stops the der from going too far out and pushing the chain off the outer chainring.

the cable tension is what holds the der in position most of the time. The limit screws only matter when there is no (or very little) tension on the cable (so the der is resting on the inner stop). Or when you push the shifter all the way in so the der is forced against the out stop.

My normal process is to:
- put the chain on the inner rings in front and in back and adjust the inner limit so you get a couple mm gap between the cage and chain (making sure there is no tension on the cable.
- put the chain in the outer rings (front and back) and set the outer limit for a couple mm gap no matter how much pressure you put on the shifter.
- then adjust the cable tension so you get good shifting between the gears.

Note that most of the time, when the shifter is in the innermost position, the cable should not really have much tension on it. Usually you just pull it tight enough to take out the slack. But if you're using a tool to put tension on the cable when the der is in the inner position, you are almost definitely putting too much tension on it.

[erdem]

thank you very much. your instructions are as clear as day.

i took away my bike to a local bike shop for FD adjustment. but i am not satisfied with the result. still chain rubs cage in some gears

i think i'll give it a try again

[AndrewB]

(07-22-2010, 04:29 AM)erdem Wrote:  thank you very much. your instructions are as clear as day.

i took away my bike to a local bike shop for FD adjustment. but i am not satisfied with the result. still chain rubs cage in some gears

i think i'll give it a try again

Which gears? Sometimes this is normal in gear situations you shouldn't be in for long periods of time, like big crank and big cog.

My Shimano front derailleur (Ultegra 6700) even says in the documentation that rubbing can happen in certain gears, and it has a third setting for such.

[erdem]

(07-22-2010, 01:45 PM)AndrewB Wrote:  Which gears? Sometimes this is normal in gear situations you shouldn't be in for long periods of time, like big crank and big cog.

when chain shifts to the middle front chainring (2nd gear) and outermost 4,5 and 6th cogs (4, 5 and 6th) gear. and also when i shift to 3rd gear (outermost front chainring i think ?!) again chain rubs to cage (3-4, 3-5, 3-6 etc..) i didn't ever tried bigger gears because i thought that it may harm chain.

dunno whether it is normal but i don't think so. coz i can't ride faster than 25 km/h (15 miles/h)

and it is hard to find a good bike mechanic in the city which i live.. quality bike mechanics are generally in metropolis.

[Surly LHT]

One ? is why did you need to adjust the FD did you put on a new chain ring set.If so you will need the FD to be no more than 2mm in height from the big chain ring.You first need to undo the cable all the way.First set the high screw then set the low screw.Then put the chain in the high gear in the back sprocket that's the little sprocket on back set the H screw first then put the chain on the low sprocket that's the big sprocket on the rear then set the low screw after all that leave it in that gear then pull all the slack out of the cable and then tighten the cable you should be set. Hope this helps.

[Surly LHT]

(07-22-2010, 06:19 PM)Surly LHT Wrote:  One ? is why did you need to adjust the FD did you put on a new chain ring set.If so you will need the FD to be no more than 2mm in height from the big chain ring.You first need to undo the cable all the way.First set the high screw then set the low screw.Then put the chain in the high gear in the back sprocket that's the little sprocket on back set the H screw first then put the chain on the low sprocket that's the big sprocket on the rear then set the low screw after all that leave it in that gear then pull all the slack out of the cable and then tighten the cable you should be set. Hope this helps.

I was looking at my repair book and told you wrong.Make sure you are in the high gear the small sprocket on the rear. And be sure to have your chain in the large chain ring on the front and the get all the slack out of your cable and you are good to go just wanted to make sure I was right this time around I know how to set one up but trying to tell some one is a little different for me lol but the rest of what I told you are right :-)...

[erdem]

(07-22-2010, 09:41 PM)Surly LHT Wrote:  

(07-22-2010, 06:19 PM)Surly LHT Wrote:  One ? is why did you need to adjust the FD did you put on a new chain ring set.If so you will need the FD to be no more than 2mm in height from the big chain ring.You first need to undo the cable all the way.

when shifting i had minor rubbing issues with the chain. so i decided to adjust FD's adjustment. but as i understood making L and H screw would be enough. but i didn't know this so i accidentaly changed also FD's height and angle adjustment.

(07-22-2010, 09:41 PM)Surly LHT Wrote:  I was looking at my repair book and told you wrong.Make sure you are in the high gear the small sprocket on the rear. And be sure to have your chain in the large chain ring on the front and the get all the slack out of your cable and you are good to go just wanted to make sure I was right this time around ..

i got it. when making H screw adjustment i need to shift outermost sprocket in rear and outermost front chainring. and for L screw vice versa. innermost ones..

(07-22-2010, 09:41 PM)Surly LHT Wrote:  I know how to set one up but trying to tell some one is a little different for me lol but the rest of what I told you are right :-)..

lol. i think your FD's adjustment skills depend on sleight of hand.

[erdem]

he he i adjusted front derailleur for the first time. if you wouldn't help me i couldn't adjust it.

thank you ever so much it took only 3 or 5 minutes to adjust front derailleur. and rubbing issues seem to be solved. haven't tested it on the road but it seems it works very well.

i wish you all the best. people of the bicycle tutorial forum and alex who prepared this site to teach us how to fix our own bikes..