Front derailleur adjustment?

tomdempsey200

hi just wondring how i adjust the front deraiileur


it's catching on the inside of the guide so i need to turn it in towards the wheels



afaik its shimano
thanks

iwillhtfu

Those philips head screws are used for slight adjustments one for lower and the other for upper but it's a black art to me. I attempted it once and ended up learning to live with the slight rub after plenty of F'ing and blinding.

Plenty of videos on youtube.

https://www.youtube.com/watch?v=vLQk29enhRQ

sy

https://www.youtube.com/watch?v=lxV_vKlgolc

paudie2005

tomdempsey200 wrote: »

hi just wondring how i adjust the front deraiileur


it's catching on the inside of the guide so i need to turn it in towards the wheels



afaik its shimano
thanks

Park tools do a good blog on adjustments
http://www.parktool.com/blog/repair-help/front-derailleur-adjustments

Unknown Soldier

iwillhtfu wrote: »

Those philips head screws are used for slight adjustments one for lower and the other for upper but it's a black art to me. I attempted it once and ended up learning to live with the slight rub after plenty of F'ing and blinding.

Those screws are just "limit" screws. One sets how far it can move in towards the bike so the chain doesn't come off the small front cog. The other one sets how far right it can move, so it doesn't come off the big cog.

I had a pain in me hole doing it and found the best way was to put the chain on the small cog, and loosen the screw holding the cable. Then push the derailleur in and visually set the inner limit. Then pull it out and set the outer one.

Take the slack out of the cable and retighten the screw holding it.

Then head off cycling, with a screw driver in your pocket and adjust the inner and outer limits until it they are more or less where you want them.

I've found everything works differently when you are cycling versus the bike on a stand or whatever.

tomdempsey200

ok thanks tor all the advice
prob not quite as simple as i expected
I'll take a look at the videos

thebikeman.ie

Unknown Soldier wrote: »

I had a pain in me hole doing it and found the best way was to put the chain on the small cog, and loosen the screw holding the cable. Then push the derailleur in and visually set the inner limit. Then pull it out and set the outer one.

Take the slack out of the cable and retighten the screw holding it.

Then head off cycling, with a screw driver in your pocket and adjust the inner and outer limits until it they are more or less where you want them.

I've found everything works differently when you are cycling versus the bike on a stand or whatever.

This is a workable method of doing it, although I wouldn't generally loosen the cable. Just use the shifters to change up and down. As Unknown Soldier says things can some times work different when cycling versus on the stand, so bring a screw driver when cycling to do the fine adjustments. When doing the fine adjustments, a quarter turn of the screw each time is enough. Once you understand what your doing this is usually a straight forward job.

tomdempsey200

which one do I turn to adjust inner limit?
and which way?
thanks

Midnight64

Step away from the allen keys. It will drive you insane. Go to a shop.

tomdempsey200

Midnight64 wrote: »

Step away from the allen keys. It will drive you insane. Go to a shop.

Allen keys?

I'm used to fixing stuff
it won't drive me insane

thebikeman.ie

tomdempsey200 wrote: »

which one do I turn to adjust inner limit?
and which way?
thanks

Looking at the photo I think it's the screw closest to the frame (although sometimes this is reversed). Check to see if they are marked with a H and L. If they are marked you want the one marked L. If not put it into low gear and try looking at the mech from the front, back or bottom to see which screw is in contact with the stop. The screw in contact with stop is the one you want.

To increase the movement of the cage turn the screw anti clockwise. Try a quarter turn at a time and keep a note of how much you have moved the screw, so you can restore it to the original position if you need to.

If you go to far the chain will be thrown off the chainwheel and you will need to adjust it clockwise. It's a fine line. If this fails to sort your problem it maybe that the cage angle is wrong, or the cable too tight. Be systematic, make quarter turn adjustments and keep notes.

tomdempsey200

thanks for the help


they were marked on the rear derailleur L H

i think the front deraileur inside limit was the screw nearest the frame

anyhow i just stuck to the basics and she's running a bit better

i'll do a bit more technical when i've researched it fully on sheldons website there

tomdempsey200

the chain is jumping slightly on the smallest cog at the back when i turn the wheel backwards?


would the derailleur be bent slightly

i changed wheels cassette and chain recently

the new cassette was slightly bigger but same 8-speed

it seems like the chain is coming in at a slight angle

letape

tomdempsey200 wrote: »

the chain is jumping slightly on the smallest cog at the back when i turn the wheel backwards?


would the derailleur be bent slightly

i changed wheels cassette and chain recently

the new cassette was slightly bigger but same 8-speed

it seems like the chain is coming in at a slight angle

I reckon you just need to adjust the tension in the rear mech cable. There is a barrel adjustment that you can turn where the cable enters the rear mech. Turn it anti-clockwise to increase the tension or clockwise to reduce it.

This will ensure that the chain sits properly on the cassette / sprocket when you change gear as opposed to shifting too far or not far enough which is most likely the case now.

thebikeman.ie

letape wrote: »

I reckon you just need to adjust the tension in the rear mech cable. There is a barrel adjustment that you can turn where the cable enters the rear mech. Turn it anti-clockwise to increase the tension or clockwise to reduce it.

This will ensure that the chain sits properly on the cassette / sprocket when you change gear as opposed to shifting too far or not far enough which is most likely the case now.

That could be it. When on the small cog (the cable in its most relaxed condition) the cable should not be under a lot of tension but neither should it be loose. Follow letape's advise on the barrell adjuster and see if that sorts it.

tomdempsey200

Will do thanks

tomdempsey200

Midnight64 wrote: »

Step away from the allen keys. It will drive you insane. Go to a shop.

it didn't drive me insane as i'm used to maintenance and fixing stuff

however i take your point as i'll prob end up at the LBS anyhow with this as it does seem to be an art rather than a science on the derailleurs


but it's worth the education anyhow

Unknown Soldier

tomdempsey200 wrote: »

it didn't drive me insane as i'm used to maintenance and fixing stuff

however i take your point as i'll prob end up at the LBS anyhow with this as it does seem to be an art rather than a science on the derailleurs


but it's worth the education anyhow

Youtube is your best friend in these situations tbh. It's not an art or a science, just mechanical manipulation.

I did my front DR about 5 weeks ago and everything was grand but it came off the big cog two days ago. That's why I carry a screwdriver in my pocket.

tomdempsey200

Unknown Soldier wrote: »

Youtube is your best friend in these situations tbh. It's not an art or a science, just mechanical manipulation.

I did my front DR about 5 weeks ago and everything was grand but it came off the big cog two days ago. That's why I carry a screwdriver in my pocket.

I started off working on the front

wrong way round I know but..

then I had a look at the back and noticed the chain was bouncing on the small cog when I turn the chain back

maybe it's no big deal on an oldish bike
I learnt a fair bit but I may end up dropping it to LBS as I was advised

or maybe I'll figure it out?..

Unknown Soldier

tomdempsey200 wrote: »

I started off working on the front

wrong way round I know but..

then I had a look at the back and noticed the chain was bouncing on the small cog when I turn the chain back

maybe it's no big deal on an oldish bike
I learnt a fair bit but I may end up dropping it to LBS as I was advised

or maybe I'll figure it out?..

The people in the LBS are just people, like you or me but with more experience.



That's how I look at it.

If you know the make of your derailleurs, throw that into the googlefacetube.

Shimano, for example, have good guides to setting the limits etc.

[edit] if you are working on the chain/cogs it it is best to keep the back cog on 4/5

Brian?

tomdempsey200 wrote: »

it didn't drive me insane as i'm used to maintenance and fixing stuff

however i take your point as i'll prob end up at the LBS anyhow with this as it does seem to be an art rather than a science on the derailleurs


but it's worth the education anyhow

I take things apart for a living as well.

There is no art to it, honestly. It's just a matter of knowing the order and doing it the same way every time.