Front or Rear Derailieur Adjustment First?

[summerdays]

I've tried fiddling a little with the LH shifter ... haven't noticed it doing a thing ... probably haven't turned it far enough ... however I think peanut may be right... or perhaps a combination of both faults?

How far would I have to twiddle the LH shifter to make a difference ? 1/4 turn 1/2 turn etc. and in which direction (I've marked it with pencil so I can go back to current setting).

Another photo sorry its a bit out of focus... taken with the camera resting against the bike frame to make that parrallel (though it doesn't look it). And in a different gear. It always rubs nearer the back of the mechanism, though in a different place this time as on smallest chain ring. (Not in a gear combo that I would ride in though).

 

[peanut]

I'm pretty sure it's straight peanut.

If you place a straight edge on the monitor along the cage outer face it definitely looks 1-2 degrees out of parallel with the large chain ring to me .
Easy enough to check just put it into the inner ring (middle ring on a triple) and the cage outer plate should be directly over and in line with the large chainring.

 

[summerdays]

I've put it in the middle ring and it's almost exactly over and in-line... just maybe the smallest fraction out but that could just be the angle I am looking at. But a useful tip to store away for future reference.

So if that's not the problem and its back to the cable tension. If I need the cage to sit further away from the bike when its not changing gear do I need to increase the cable tension? Or is it time to tinker with the limit screws - the H one?

 

[peanut]

I've put it in the middle ring and it's almost exactly over and in-line... just maybe the smallest fraction out but that could just be the angle I am looking at. But a useful tip to store away for future reference.

So if that's not the problem and its back to the cable tension. If I need the cage to sit further away from the bike when its not changing gear do I need to increase the cable tension? Or is it time to tinker with the limit screws - the H one?

well if near enough is good enough then I doubt you'll find a satisfactory solution.
You can't expect to get perfect smooth running of your transmission if you are happy to accept a little bit of inaccuracy here and there. They all add up !

It might look like a little bit out but it only needs to be moved 1-2 mm and the noise will probably go away . Thats about 1-2 degrees off parallel.

I would recommend that you lift off the chain from the chainrings and set the front mech precisely according to the manufacturers recommendations before you do anything else.
Use a ruler to set the cage front plate in line with the big chainring. Set the front cage plate 1-3mm vertically above the teeth of the big ring (no more)when the front plate of the cage is directly vertical above the teeth of the big ring.


Replace the chain and check from the rear of the bike that the 2x jockey wheels of the rear mech are perfectly vertical and in line with the large chain ring by eyeing them up from the rear.

Put the chain on the biggest ring and the biggest cassette sprocket and check the jockey wheels are vertically in line directly under the centreline of the rear axle . If not adjust chain length accordingly.

At least then your adjustments of the cables and mech stops will be meaningful

Near enough is not good enough ok

 

[summerdays]

OK I've done some of the above... I have adjusted the front derailieur angle so that it only rubbed when on the smallest sprocket ... now it won't change down to the smallest chain ring - see some people aren't meant for maintenance.

I assume there isn't enough angle pushing it towards the bike now

Do I try to recover back to when I could change rings or carry on messing it up?

What is so galling is that I'm sure some folk are probably thinking they could do it blind folded.

 

[Willow]

Just reading this is confusing me, I get loads of cyclists going past my house at weekends and was wondering about the wisdom of putting a sign up asking for bike maintenance help

 

[peanut]

Just reading this is confusing me, I get loads of cyclists going past my house at weekends and was wondering about the wisdom of putting a sign up asking for bike maintenance help

try a red light actually a sign is not a bad idea. I would really like to see some bartering at local area level. A swopping of skills would be brilliant but I can't see it working.

 

[peanut]

now it won't change down to the smallest chain ring

I assume there isn't enough angle pushing it towards the bike now

.

the angle of the cage is only a fraction of the factors and adjustments needed to prevent the chain rubbing.
Why have you only done some of the things suggested ???
How do you know which is required and which is not ??

if you have done exactly as I suggested then you are ready to start adjusting your front and rear mechs.
DO NOT bend the mechs about the only adjustments needed now everything is aligned is simply philips screws and cable adjusters.

You need to adjust the cable adjuster for the front mech to allow a tiny bit more slack in the front mech gear cable.
There should be a adjuster where the gear cable enters the frame boss on the head or down tube if it is a road bike .Follow the cable from the gear lever to the front mech and find the adjuster. you'll only need about a 1/4 turn.
this is too difficult to do like this sorry you need to get someone to show you how to do this.

 

[summerdays]

I'm sorry I don't know why I don't understand the mechanics... I guess I'm always afraid of really mucking it up and making it un-rideable... and I obviously don't trust myself not to muck it up. I could just take it to the LBS (they just shake their heads at me and smile and then usually try to explain one part of the job) but I do want to try and learn too.

I didn't bend the mech - just undid a bolt at the back to slide it around a very small amount. Then I tested it to see what the result was - kind of learning what it does and then discovered it wouldn't change down and panicked.

I've tried turning the adjuster both directions by upto half a turn and haven't been able to work out any change to the mechanism. I am mechanically thick.

 

[peanut]

I'm sorry I don't know why I don't understand the mechanics... I guess I'm always afraid of really mucking it up and making it un-rideable... and I obviously don't trust myself not to muck it up. I could just take it to the LBS (they just shake their heads at me and smile and then usually try to explain one part of the job) but I do want to try and learn too.

I didn't bend the mech - just undid a bolt at the back to slide it around a very small amount. Then I tested it to see what the result was - kind of learning what it does and then discovered it wouldn't change down and panicked.

I've tried turning the adjuster both directions by upto half a turn and haven't been able to work out any change to the mechanism. I am mechanically thick.

if you are not mechanically minded you really shouldn't be attempting any of this because evry single adjustment you make without knowing what you are doing is just going to make things worse.

Just find another cyclist to help or put it in your LBS .
I wasn't getting impatient with you just frustrated at the unsuitability of attempting this through typing