Aligning your derailleur...

.ak

So my chain is slipping a bit, and clanking when I switch gears. And when I'm on a trail my chain is slipping completely. Don't think it's the chain or the cogs as the bike is fairly new (March with not an awful lot of KMs under its belt) Reckon it's the derailleur... I tried fiddling with the tension and high/low point screws last night and thought I had it running pretty smooth but on the way to work today it's making an awful noise.

Is it something I should be able to figure out at home? Or should I book it into a LBS to have it re-aligned?

I'm not a big fan of bringing my bike into a LBS for these things, as I will never learn how to fix it myself otherwise.

07Lapierre

http://www.youtube.com/watch?v=SjJfKO_tAo0

.ak

07Lapierre wrote: »

http://www.youtube.com/watch?v=SjJfKO_tAo0

Thanks. I did view a similiar video before tinkering with it... but I'm not seeing as much movement in the cage as in those videos... and obviously my tinkering didn't help.

EDIT: although that video looks a bit better, with the visual lines for aid.

ford2600

http://www.parktool.com/blog/repair-help/rear-derailler-adjustments-derailleur

It helps if you understand why your adjusting whatever it is your adjusting.

A derailleur just moves over a back between largest and smallest cog(movement limited by limit screws at either end). Cable tension acts against spring tension.

The spring pulls derailleur towards smallest cog and cable tension works in other direction. The indexed shifter controls movement in this direction.

Your cable has probably stretched a little, reducing tension. A small adjustment will correct this.

07Lapierre

.ak wrote: »

Thanks. I did view a similiar video before tinkering with it... but I'm not seeing as much movement in the cage as in those videos... and obviously my tinkering didn't help.

EDIT: although that video looks a bit better, with the visual lines for aid.

No worries, There's a tutorial video on youtube for everything

simonrooneyzaga

07Lapierre wrote: »

http://www.youtube.com/watch?v=SjJfKO_tAo0

thanks for this - was having a similar issue with the lowest gear rubbing against the spokes slightly and this looks like it will fix it and save me dropping it into the bike shop :-)

MB Lacey

07Lapierre wrote: »

No worries, There's a tutorial video on youtube for everything

Which is why my posh mac white keyboard keys are covered with a black grease from the bike.
Tried to clean the grease off once and killed my keyboard, so I had a broken bike and keyboard

I find that the deraileurs always move so obviously in these youtube videos, in reality when I turn the limit screws nothing obvious happens.
Same with limit screws on front deraileur.
Any time I've been near the limit screws I've had to take it to lbs to fix my mess.
Going to sign up to do the maintenance course in rothar one day.

.ak

Yep, that's what's happening to me, I'm turning the screws but it's not really moving at all... and then when I jump on and cycle it I've made a mess of things. :P

jober

I had a similar problem, tinkered with all the limit screws and barrel adjuster as in many of the you-tube vids

Then I realised I had to disconnect the cable from the derailuer and start from scratch and with in minutes I had everything working properly and smoothly saved myself a visit to the lbs

07Lapierre

MB Lacey wrote: »

Which is why my posh mac white keyboard keys are covered with a black grease from the bike.
Tried to clean the grease off once and killed my keyboard, so I had a broken bike and keyboard

I find that the deraileurs always move so obviously in these youtube videos, in reality when I turn the limit screws nothing obvious happens.
Same with limit screws on front deraileur.
Any time I've been near the limit screws I've had to take it to lbs to fix my mess.
Going to sign up to do the maintenance course in rothar one day.

The chain will move, but only if the chain is on the large or small sprocket AND you are turning the correct screw. As per the video i linked to, stand at the rear of the bike and look along the chain line. If your turning the correct screw you will see the derailler move (1/4 of a turn is usually more than enough). Also, turn the pedals while adjusting the limit screws..if the rerailler is off line, there will be a clicking noise. As you turn the screw the noise should go away as the chain moved in-line with the sprocket. If the noise gets worse, or the chain moves onto the next sprocket, your turning the screw the wrong way.

clog

The limit screws are there partly to stop the mech's shifting off the sprocket's/rings. They will only move the mech's when at the extremities and even then they will not move against cable tension. Be very careful adjusting limit screws especially those on the rear as if the low limit is not set correctly then the mech can be shifted right into the spokes of the back wheel, I have seen this many times and it can be very costly.

The adjuster on the mech or the barrel/downtube adjuster is the one to use once the limit has been set. It's no good setting for example the high limit on the rear without making sure the cable tension is there in order for the shifters to work properly

.ak

What about your front gears, should you be on the middle gear when doing the adjustments, does it make a difference? I'm getting a grinding noise as the chain is running against the front derailleur a bit... Especially in the highest gear.

clog

Set the front mech off the lowest gear first; (small front ring, large rear sprocket), set the low limit on the mech itself and make sure that the cable is tensioned. Then try shifting through gears the highest gear (large front,small rear) if the front mech is rubbing and does not seem to want to move over enough you may need to let out the high limit limit screw or increase cable tension to take up the slack.

simonrooneyzaga

simonrooneyzaga wrote: »

thanks for this - was having a similar issue with the lowest gear rubbing against the spokes slightly and this looks like it will fix it and save me dropping it into the bike shop :-)

Made the adjustment there and took her for a spin around the block. No horrible spokey noises anymore, great!

Still finding that the second and third lowest gears are being very jumpy and the second lowest especially would be useless to me for tonight's climbing.

Is this problem fixed by adjusting the barrel adjuster?

I am in need of a service too (waiting for payday), but if I could make a small adjustment as per my other issue that would be great.

Tzarkahn

This is fairly anecdotal, but I found that the cable tension was the main thing (Barrel Adjuster) and the screws made very little difference aside from getting the smallest rear cog in place properly.

07Lapierre

Tzarkahn wrote: »

This is fairly anecdotal, but I found that the cable tension was the main thing (Barrel Adjuster) and the screws made very little difference aside from getting the smallest rear cog in place properly.

Your right, but the OP did say that he'd "fiddled" with the limit screws in an attempt to sort out the gears.

quozl

simonrooneyzaga wrote: »

thanks for this - was having a similar issue with the lowest gear rubbing against the spokes slightly and this looks like it will fix it and save me dropping it into the bike shop :-)

If you fixed it by adjusting cable tension then you should also fix it by setting the low limit screw.

So that if your cable stretches the derailleur won't move back into the spokes.

The limit screws are the hard-stops for where the derailleur will move to.

simonrooneyzaga

quozl wrote: »

If you fixed it by adjusting cable tension then you should also fix it by setting the low limit screw.

So that if your cable stretches the derailleur won't move back into the spokes.

The limit screws are the hard-stops for where the derailleur will move to.

Yeh I didn't touch the b adjuster, just turned the bottom limit screw clockwise a few times and it's stopped making the noise now!

ford2600

simonrooneyzaga wrote: »

Yeh I didn't touch the b adjuster, just turned the bottom limit screw clockwise a few times and it's stopped making the noise now!

Sounds a bit hit and miss!

Have a read of this and then follow procedure and you should be good to go.

http://www.parktool.com/blog/repair-help/rear-derailler-adjustments-derailleur

simonrooneyzaga

ford2600 wrote: »

Sounds a bit hit and miss!

Have a read of this and then follow procedure and you should be good to go.

http://www.parktool.com/blog/repair-help/rear-derailler-adjustments-derailleur

Thanks for that Ford2600!

magicbastarder

is it a stretchy cable issue when the derailleur runs smoothly on the smaller cogs on the freewheel, but starts to chatter a bit as you shift to the bigger cogs?

quozl

Doesn't sound like cable stretch to me. Could be the derailleur hanger is slightly bent - that can only affect one end of the cassette if it's a minor enough misalignment.

blobbie

simonrooneyzaga wrote: »

Still finding that the second and third lowest gears are being very jumpy and the second lowest especially would be useless to me for tonight's climbing.

Sometimes jumpy gears are a result of a stiff chain link, especially after replacing a chain. Here is a UTube of how to resolve if this is your issue;

https://www.youtube.com/watch?v=hklVw3KErKw

djerk

i found this site quite helpful when i was fixing my derailleur before : http://www.parktool.com/blog/repair-help
just click on the various parts of the bike and go from there.

also found some useful pdf's by going directly to the manufacturer.. in my case 'shimano'. its a really finicky process but well worth doing. can be a bit of a pain unless you can mount the bike on a stand because you constantly need to change gears and rotate the crank to check your adjustments.

blobbie

Thanks for that link.

Time to print to PDF, store to Google Drive and make available on phone for back of nowhere emergency repair guides.

.ak

Got the rear derailleur sorted. Switching through the gears pretty crisply now... Little snappy when under load but I'm okay with that for now...

Unfortunately I had a bit of a Father Ted moment though when I fixed the rear derailleur the front was chaffing off the chain on several gears. I found the front derailed far harder to move, and in my eagerness I over did the releasing of the tension at the shifter... So the shifter tension cable unit nut came free of the housing. Not an issue in itself, but when I tried putting it back in the threading became damaged... So now I can't get it back in.

Trip to my lbs on Wednesday and see if they can fix it.

Although frankly I'm thinking of converting the front mech to a single speed so it's 1x9. I just find on the road I almost never use anything other than the middle front gear, and on the trails my chain keeps jumping off the front anyway. So a single chain ring up the front with correct tension and a chain guide may be the answer to simpler mtbing.

Don't think I'd attempt the conversion myself tho, I seem to be all thumbs with any mechanical stuff.

diomed

.ak wrote: »

the bike is fairly new

That says the cable has stretched a little as it does on all new bikes.
The easy fix is, using the gear changers, put the chain on the big chainwheel on the front. Then using the other gear shifter lever move the chain to the middle sprocket on the back (e.g. 5th of 10 sprockets). Hold the back wheel off the floor and turn the pedals. If there is a rattle at the back sprocket turn the black adjuster that is on the small curved cable at the very back of the bike a turn one way. Is the rattle gone, or worse? Turn more one way, or if that is worsening it, turn it the other way until the rattle disappears. Then you can change gear on to the other back sprockets to confirm that the rattle is gone. You might need to turn it a quarter turn to get it perfectly quiet.
If you have been adjusting every screw and nut on the bike the above might not be possible.

Unknown Soldier

Probably worth noting that when you are setting the gears etc on a stand it can differ a fair bit when you are riding the bike, so I found.

Once I've done the bike on the stand I tend to take a spin and adjust further with some tools.

Once the limit screws/points are set, it's just tweaking using the "barrel" adjustment knob yoke.


Another thing worth checking is if the rear hanger is bent. On two occasions I thought it was a problem and just couldn't see how, until I took it them off. Such a tiny twist/bend that you can't see when it's on the bike

Brian?

One thing that's caught me out in the past: make sure the bolt that mounts the derailleur to the hanger is good and tight. It may loosen over time.

.ak

Yeah dropping it down to the lbs on Wednesday anyway, so will be interesting if they can tell me where or how I went wrong.

Qualitymark

MB Lacey wrote: »

Which is why my posh mac white keyboard keys are covered with a black grease from the bike.
Tried to clean the grease off once and killed my keyboard, so I had a broken bike and keyboard.

Baby wipes, I find. With the computer switched off and unplugged, obv, and give it time to dry off, or (I'm told) dry it with a hairdryer.