Constant noise on higher (largest) chainring - 105 groupset

jimmm

I have a 10 day old Cannodale CAAD10 105, and have been experiencing a constant noise when on the largest (higher) chainring. It happens on whatever gear I am on, on the rear cassette. It only happens when I am pedalling - and then is quiet when I am coasting.

I'm not sure if this has happened since I first bought/rode it - as I did take it back to the shop (after 3 days) for a minor adjustment on the gears as there was a constant sort of clicking noise when on some gears - but after a minor adjustment and a lesson not too use the lowest and highest gears if possible on the rear cassette as the chain won't be straight and there will be a noise.

Does anyone have any ideas of what it may be - or should I take it back for another checkover at the LBS?

avoidingmyphd

it's hard to be sure remotely but it's probably cable stretch. the gear cable has stretched slightly, so it no longer goes tight enough to get the cable all the way onto the big ring. this is normal on a new cable. it needs tightening slightly. unscrew the adjuster on the down tube about a quarter turn.

your lesson about avoiding the extremities of the cassette sounds wrong as well. avoid big-big and small-small. it's fine to use big-small (the fastest gear on the bike) and small-big (the slowest gear).

you shouldn't need to take it back to the shop for gear adjustments. ask on here, look at the park tools website and google the shimano tech docs for the 105 groupset. gear adjusting is easy.

jimmm

I just phoned up the LBS and from my description (as above) they think that it may be caused by the chain or chain ring rubbing on the front derailleur. I have booked it in for Thursday - so I'm hoping it is nothing too serious. They said that the bike will be fine to ride until then - would you lot agree? I don't want to end up causing damage that is going to cost me.

Ah ok thanks for the heads up about the gearing extemities. That is probably what they told me - I may have interpreted it wrong!

jimmm

I've also just noticed a really small paint chip on the frame - as if it's got stabbed by a pin - so I'm guessing its been caused by a really sharp stone flicking up. What is the best course of action for touching this up? I've seen nail varnish is recommended, but is it best to pick up a car touch up kit from Halfords? The colour scheme of my CAAD10 is Liquigas - and it has happened on the white - so shouldn't be too hard to match.

As the frame is aluminium - I'm guessing there is no harm in just leaving it either?

Pross

jimmm wrote:

I just phoned up the LBS and from my description (as above) they think that it may be caused by the chain or chain ring rubbing on the front derailleur. I have booked it in for Thursday - so I'm hoping it is nothing too serious. They said that the bike will be fine to ride until then - would you lot agree? I don't want to end up causing damage that is going to cost me.

Ah ok thanks for the heads up about the gearing extemities. That is probably what they told me - I may have interpreted it wrong!

Sounds the most likely explanation. It's literally a 10 second job with a scredriver to tweak the limit screw so that it doesn't rub

smidsy

I would agree that it is probably the chain rubbing on the faceplate of the front mech. Simply get a screw driver and adjust it so it has about 1mm clearance. Also worth checking it is nice and paralell to the chainrings as it may have moved around the seat tube.

With regards to chips, the aluminium can react if left which then starts the paint bubbling in these areas so best get it touched up - although you will soon find that white is no easier to match than blue, green or red etc etc.

itsnotarace

Pross wrote:

Sounds the most likely explanation. It's literally a 10 second job with a scredriver to tweak the limit screw so that it doesn't rub

smidsy wrote:

I would agree that it is probably the chain rubbing on the faceplate of the front mech. Simply get a screw driver and adjust it so it has about 1mm clearance.

Load of crap. The first poster replied with the correct answer. Pissing about with the limit screws will just ensure the chain drops off the front rings onto your feet. Unwind the barrel adjuster on the front mech by 1/4 turn to adjust the cable tension.

jimmm

Thanks for the replies - really appreciated. Is nail polish ok to use for a really small touch up? Some messageboards state that its not the best thing to use as the chemicals in it can react with some materials? My girlfriend has white and also a clear varnish so I can give it a cover up tonight to avoid any reactions.

I just popped into Halfords to have a look at their car scratch repair kits - and there was about 20 different whites!

jimmm

itsnotarace wrote:

Pross wrote:

Sounds the most likely explanation. It's literally a 10 second job with a scredriver to tweak the limit screw so that it doesn't rub

smidsy wrote:

I would agree that it is probably the chain rubbing on the faceplate of the front mech. Simply get a screw driver and adjust it so it has about 1mm clearance.

Load of crap. The first poster replied with the correct answer. Pissing about with the limit screws will just ensure the chain drops off the front rings onto your feet. Unwind the barrel adjuster on the front mech by 1/4 turn to adjust the cable tension.

It's probably best I am taking it into the LBS then, as I'm very much a beginner with all this - so wouldn't know what to look out for for either. I will ask them exactly what it is though so I can do it myself if it is to happen again.

smidsy

itsnotarace wrote:

Pross wrote:

Sounds the most likely explanation. It's literally a 10 second job with a scredriver to tweak the limit screw so that it doesn't rub

smidsy wrote:

I would agree that it is probably the chain rubbing on the faceplate of the front mech. Simply get a screw driver and adjust it so it has about 1mm clearance.

Load of crap. The first poster replied with the correct answer. Pissing about with the limit screws will just ensure the chain drops off the front rings onto your feet. Unwind the barrel adjuster on the front mech by 1/4 turn to adjust the cable tension.

Call me picky but do I detect that you may not agree with our diagnosis

You may well be right but I thought it was easier to start with the simplest item.

Pross

itsnotarace wrote:

Pross wrote:

Sounds the most likely explanation. It's literally a 10 second job with a scredriver to tweak the limit screw so that it doesn't rub

smidsy wrote:

I would agree that it is probably the chain rubbing on the faceplate of the front mech. Simply get a screw driver and adjust it so it has about 1mm clearance.

Load of crap. The first poster replied with the correct answer. Pissing about with the limit screws will just ensure the chain drops off the front rings onto your feet. Unwind the barrel adjuster on the front mech by 1/4 turn to adjust the cable tension.

You won't drop the chain by making a minor adjustment to the limit screw to stop it rubbing. I would use the barrel adjuster at the rear but using the limit screw at the front to ensure the mech is just clear of the chain when running outside chainring / outside sprocket won't do any harm, it was the only way to do it before integrated shifters came out. People seem to be pampered these days.

EDIT Also, if it is that the limit screw isn't allowing the mech enough travel rather than cable stretch then all the poncing about with barrel adjusters in the world won't sort the problem out.

ShutUpLegs

jimmm wrote:

I've also just noticed a really small paint chip on the frame - as if it's got stabbed by a pin - so I'm guessing its been caused by a really sharp stone flicking up. What is the best course of action for touching this up? I've seen nail varnish is recommended, but is it best to pick up a car touch up kit from Halfords? The colour scheme of my CAAD10 is Liquigas - and it has happened on the white - so shouldn't be too hard to match.

As the frame is aluminium - I'm guessing there is no harm in just leaving it either?

Touch up paint always looks like shite. Often it looks worse than the chip

itsnotarace

Edit - I got it the wrong way round, the cable is slightly too loose and the barrel adjuster needs to be tightened a 1/4 turn

Pross

If the mech limit screw isn't giving the mech enough travel it's irrelevant whether ther is too much tension, not enough tension or perfect tension it will still rub. It's hard to take advice from someone who seemingly can't adjust limit screws without unshipping their chain. How did people manage to adjust their front mechs before barrel adjusters?

itsnotarace

The limit screws (clue is in the name) just prevent the mech moving the chain past the intended point. If the mech moves the chain to the large chainring and no further, then the limit screw is set correctly.

Fine tuning is via cable tension which is what the barrel adjuster is there for.

Hope that helps

Pross

Yes but the limit should be set far enough that it not only goes onto the chain ring but there is a small gap between the outer plate and the chain otherwise fine tuning the mech with the barrel adjusters will have no effect. That is why it would be my first move. Either may be the required solution but your assertion that adjusting the limit screw will leave you with the chain around your feet is not the case if done properly. Front mechs are simple things and other than a bit of trimming adjustment is easy, its only moving the chain between two chainrings after all!

migrantwing

Personally, I find the new (5700) 105 FD's absolute cr*p. I've never had so much faffing around with an FD in my life. I've changed the FD height, rotation, and messed around with limit screws. I think the fact that it is a compact chainring causes a few problems. All I ever get is chainrub.

Pross

OK, I've got a proper keyboard now rather than a phone. It could be either the tension or the limit screws but it should be pretty easy to work out. Put the bike in its biggest gear (large chainring, smallest sprocket), push the gear lever over as far as it will go. If the front mech goes far enough out that it no longer rubs on the chain but then jumps back once you release the pressure on the lever then the tension is too high and needs adjusting on the barrel adjusters. However, if the mech just doesn't go far enough over to stop the outer plate rubbing on the chain it is likely to be the limit screw. If this is the case slacken the H limit screw a small amount (1/8th of a turn at a time)and the mech should start moving outwards away from the chain (if nothing happens then it suggests there is a tension issue).

Whilst it makes sense to take the bike back to the shop as it is so new it is worthwhile learning basic maintenance like this. Park Tools and Sheldon Brown websites are very good ways to learn these things.

Cleat Eastwood

Pross wrote:

If the mech limit screw isn't giving the mech enough travel it's irrelevant whether ther is too much tension, not enough tension or perfect tension it will still rub.

Thats the fact of the matter. Relying on altering cable tension to affect the travel of the mech is asking for trouble.

CiB

Blimey it's not rocket science. A lever with a ratchet on it pulls or releases a cable that moves the mech across, guiding the chain from one ring to the other.

How much effort is it to just look at and decide whether the range from one end to the other is enough, or whether the cable is a bit slack and needs a bit more tension?

I know newcomers are often a bit fazed by shiny new technology but mechs work exactly the same way now as they did when God's dad invented them, and they were pretty simple then.

OP - have a look, see what's going on and report back. It's time to dust off my old cliché and point out that you'd no sooner take the bike to a shop to have the gears tweaked than you'd take your guitar in to have it tuned.

Sorry for the impatience, but all this second-guessing going on when all it needs is to have a look to identify the issue does my ed in.

itsnotarace

Cleat Eastwood wrote:

Pross wrote:

If the mech limit screw isn't giving the mech enough travel it's irrelevant whether ther is too much tension, not enough tension or perfect tension it will still rub.

Thats the fact of the matter. Relying on altering cable tension to affect the travel of the mech is asking for trouble.

If the cable isn't tight enough, you can wind out the limit screw all you like. The mech won't move :idea:

itsnotarace

Pross wrote:

How did people manage to adjust their front mechs before barrel adjusters?

Sorry, I missed this before.

Well for a start, back in the day we had downtube shifters with friction shifting for both front and rear mech

Then some of us had indexed rear gears, and friction shifting front

Then integrated shifters/brakes were invented and barrel adjusters appeared around the same time

So you're right, these days its easy to feel pampered

Pross

itsnotarace wrote:

Cleat Eastwood wrote:

Pross wrote:

If the mech limit screw isn't giving the mech enough travel it's irrelevant whether ther is too much tension, not enough tension or perfect tension it will still rub.

Thats the fact of the matter. Relying on altering cable tension to affect the travel of the mech is asking for trouble.

If the cable isn't tight enough, you can wind out the limit screw all you like. The mech won't move :idea:

True, but you were adamant that it was the cable being to tight and that it could be nothing else previously

Cleat Eastwood

itsnotarace wrote:

Cleat Eastwood wrote:

Pross wrote:

If the mech limit screw isn't giving the mech enough travel it's irrelevant whether ther is too much tension, not enough tension or perfect tension it will still rub.

Thats the fact of the matter. Relying on altering cable tension to affect the travel of the mech is asking for trouble.

If the cable isn't tight enough, you can wind out the limit screw all you like. The mech won't move :idea:

Have you any experience with this at all? Heres what you do.

1. set limits of screw for lowest gear - no cable attached - and amazingly the mech moves.
2. attach cable
3. put gear into highest
4. adjust limit screw for high gear.

so do you attach the cable then put the mech to lowest gear, then adjust the screw?

As pross said you have as much tension in teh cable as you like but if the mech is set wrong it will rub and rub and rub.

Have a look at this guy

http://www.youtube.com/watch?v=ngm6dr-1na0

I look forward to you posting comments below his vid telling him that he's wrong.

jimmm

Just got back from the LBS and they said they believe there was a bit of chain rub on the front derailleur due to the cable being a bit stretched due to being the bike and components being new. They said that they altered the barrel adjuster (front shifter) to tighten the cable. When I rode it back to work the noise was quieter - but it sounds like there is still a bit of chain rub - especially when I'm going higher speeds.

So I think it may require a little bit more adjustment using the barrel adjuster. I'm guessing it needs to be tightened a bit more? - Would that require me to turn the barrel adjuster clockwise? - Also how much should I turn the barrel adjuster at one time? 1/4 turn? Or more?

CiB

Why not try it and see?

jimmm

I did a quarter turn and there was no difference - so did a quarter turn back to what the LBS had set it at and left it like that.

I turned my bike upside down and got closer to all the gears and checked the front derailleur for any rubbing. There is only rubbing on the most extreme gear now Big-Big/Small-Small - which I'm know is expected to a certain degree.

However it appears the noise that I am getting now is coming from the rear derailleur. I couldn't see any rubbing - is it expected to get some level of noise coming from it when you are in higher gears - or should it be quiet?

drlodge

jimmm wrote:

However it appears the noise that I am getting now is coming from the rear derailleur. I couldn't see any rubbing - is it expected to get some level of noise coming from it when you are in higher gears - or should it be quiet?

I would try to get your head round how the front and rear derailleurs work so you can adjust them yourself. Typically on a new bike you will get cable stretch so the barrel adjuster can be used to compensate. However if the mech isn't setup right in the first place you'll always have problems.

I had a problem recently after installing new cables/brifters on my bike - the chain was jumping off the largest rear cogs when I was standing up a steep hill, the cable had stretched so the rear derailleur was trying to upshift. adjust the barrel adjusted and bingo, problem solved.

You could try tweaking the barrel adjuster and see if that solves your problem. I setup my rear derailleur without the chain on, and eye ball the top jockey wheel to align with the cassette cogs. That way I know its setup perfectly and once the chain is back on just check that it works as expected.

jimmm

There's no gear jumping and the gears shift pretty smoothly. Doesn't appear to be any rubbing either - I will have a proper look tomorrow though. If there's no rubbing I will have a play around with the barrel adjuster to see if it quitens down the noise at all.

Thanks for the advice everyone by the way. I want to learn it all so I cn do it all myself - but don't want to make an error which will either cost my wallet getting it rectified or damage my bike.

extrusion

The transmission will make noise, that's the nature of the device. My bike is really quiet on the small front ring, noiser on the big. I presume this is because the chainline is more angled. You can tell when it's chain rubbing on the front derailleur though, or trying to skip up a gear at the rear. Or maybe that comes with experience?

As the bike shop has adjusted the bike for you I would say it's fine and what you are experiencing is normal. If you have noise OCD (like i do) you can spend a lot of time fiddling on each ride until one day it clicks that actually, that's just the noise it makes.

jimmm

I'm pretty sure it is an OCD, you're right - especially as the bike is still so new!

But it does seem considerably louder on the big chain ring. Constant louder and higher pitch noise than when on the smaller chain ring - which is a LOT quieter (but still constant if I listen out carefully). I've turned my bike upside down at home and gone through the gears and pedalled with my hands - and their is definitely a louder noise coming from the rear derailleur when on the big chain ring - and from all my checks I can't see any rubbing.

Need to forget about it and just enjoy riding it! I have my first service in four weeks so will see if it gets any better by then; and if not make them aware of it to see if they can quiet it down at all.