Chain hitting crank arms??

martziniuk

Hi all,

I’ve got a problem when I stand to pedal. When the bike starts swaying I hear a chinking noise as the chain appears to sway and hit the crank arm. The crank arm does have marks from where the chain has hit it.

The bike has had a new chain, chain rings, rear cassette and rear derailleur. It’s a 20 speed but it seems to happen in any gear above tenth.

The only thing I can think of is when someone put a new bottom bearing in maybe they missed off some spacers?
Any help much appreciated.

Bike is a 2015 Giant advanced 3

amrushton

What do you mean swaying? The chain is held in tension by the chainring and lower jockey wheel (tension pulley). The chain normally moves in a vertical plane on a rough road not side to side. The way you describe it the chain is moving out to the right when the r/h crank arm is moving upwards past the cassette to the vertical position

Alejandrosdog

it sounds like you either have a sticky derraileur thats not pulling back enough to keep the chain in tension, OR the chain is too long OR Both.

cougie

How can it hit the cranks - if it is then it's not on the chainring. Of its not on the chainring you're not going anywhere.

martziniuk

I’m meaning the action of the bike swaying from side to side when you stand and push hard, causing the bike to sway about.
It’s a brand new derailleur, the same thing happened with the old one. If I take a link out it doesn’t have enough chain to hit all gears, so I have just enough links for it to work. The chain isn’t ever slack but maybe I need to adjust the back tension screw as much as it will go?
Gear shift are pretty much perfect by the way, just this damn chinking sound when in standing riding position.

manoirdelourde

I think you need to take the bike into your local bike shop and speak to someone who knows what they are doing, I can’t imagine any scenario where your chain can hit your crank arms . . . .

Alejandrosdog

manoirdelourde wrote:

I think you need to take the bike into your local bike shop and speak to someone who knows what they are doing, I can’t imagine any scenario where your chain can hit your crank arms . . . .

Bendy frame

martziniuk

Edit: just had another look, it’s not hitting the crank arms, I now believe it maybe the rear cassette and chain clipping sprockets as the bike rocks.
God knows!

cougie

Not the chain hitting the chainstay then ?

Or the mech touching the spokes ?

Impossible to solve this as nobody's sure of your actual problem...

amrushton

Martziniuk wrote:

Edit: just had another look, it’s not hitting the crank arms, I now believe it maybe the rear cassette and chain clipping sprockets as the bike rocks.
God knows!

the chain is either on the sprockets albeit it may be rattling or skipping or it is off the cassette and down behind the cassette or between the smallest cog and the chainstay. I've had a seized guide pulley (top jockey wheel) which resulted in the chain being sloppy when back-pedalled but forward pedalling and freewheeling should always have chain under tension (unless chain is too long).

martziniuk

cougie wrote:

Not the chain hitting the chainstay then ?

Or the mech touching the spokes ?

Impossible to solve this as nobody's sure of your actual problem...

No neither of them.
I’m just hearing a high pitched chinking noise, I think the chain might be trying to jump but actually never has.

pilot_pete

It’s a 20 speed but it seems to happen in any gear above tenth.

So, only when in the big chainring.

Sounds like either the indexing of the front derailleur is out and the chain is catching (which would seem unlikely in every gear on the rear cassette) on the front derailleur cage, or that the crank arm is catching the front derailleur cable (often the end protruding from the mech with the cap on it can be bent outwards meaning it catches the crank arm on every pedal stroke). It could be that only with the flex from pedalling whilst out of the saddle that the crank arm just comes close enough to catch the cable end.

If you can’t diagnose any more accurately we are all just guessing....maybe a video taken on a turbo trainer could help us diagnose?

PP

martziniuk

Pilot Pete wrote:

It’s a 20 speed but it seems to happen in any gear above tenth.

So, only when in the big chainring.

Sounds like either the indexing of the front derailleur is out and the chain is catching (which would seem unlikely in every gear on the rear cassette) on the front derailleur cage, or that the crank arm is catching the front derailleur cable (often the end protruding from the mech with the cap on it can be bent outwards meaning it catches the crank arm on every pedal stroke). It could be that only with the flex from pedalling whilst out of the saddle that the crank arm just comes close enough to catch the cable end.

If you can’t diagnose any more accurately we are all just guessing....maybe a video taken on a turbo trainer could help us diagnose?

PP

Thank you for that reply.
It’s not the front derailleur cage catching, that’s a very different sound.
I’ll double check the cable catching because it has happened before but I’m sure it was a different sound, this is quite loud, enough to make people look.
I don’t have a turbo trainer anymore and I’m not sure the swaying effect I have on the bike when pedalling hard could be reproduced that way to make the noise.
I may have to try with my phone strapped to the bike

cougie

A bit of ducktape will secure your phone to the bike.


What could possibly go wrong ?

;-)

redvision

Take it you your lbs

StillGoing

Martziniuk wrote:

Hi all,

I’ve got a problem when I stand to pedal. When the bike starts swaying I hear a chinking noise as the chain appears to sway and hit the crank arm. The crank arm does have marks from where the chain has hit it.

The bike has had a new chain, chain rings, rear cassette and rear derailleur. It’s a 20 speed but it seems to happen in any gear above tenth.

The only thing I can think of is when someone put a new bottom bearing in maybe they missed off some spacers?
Any help much appreciated.

Bike is a 2015 Giant advanced 3

Take the bike to someone that knows what they're doing.

martziniuk

philthy3 wrote:

Martziniuk wrote:

Hi all,

I’ve got a problem when I stand to pedal. When the bike starts swaying I hear a chinking noise as the chain appears to sway and hit the crank arm. The crank arm does have marks from where the chain has hit it.

The bike has had a new chain, chain rings, rear cassette and rear derailleur. It’s a 20 speed but it seems to happen in any gear above tenth.

The only thing I can think of is when someone put a new bottom bearing in maybe they missed off some spacers?
Any help much appreciated.

Bike is a 2015 Giant advanced 3

Take the bike to someone that knows what they're doing.

Thanks for the workshop advice
I’ll persevere, it’s not a problem just a bit of noise

First.Aspect

Could be more than a bit of noise if you don't figure it out and carry on using it.

The advice to go to a mechanic is based on the fact that you aren't able to explain the problem clearly enough for anyone to advise you, so the chances of you fixing it don't seem all that great.

StillGoing

Martziniuk wrote:

philthy3 wrote:

Martziniuk wrote:

Hi all,

I’ve got a problem when I stand to pedal. When the bike starts swaying I hear a chinking noise as the chain appears to sway and hit the crank arm. The crank arm does have marks from where the chain has hit it.

The bike has had a new chain, chain rings, rear cassette and rear derailleur. It’s a 20 speed but it seems to happen in any gear above tenth.

The only thing I can think of is when someone put a new bottom bearing in maybe they missed off some spacers?
Any help much appreciated.

Bike is a 2015 Giant advanced 3

Take the bike to someone that knows what they're doing.

Thanks for the workshop advice
I’ll persevere, it’s not a problem just a bit of noise

The post highlighted that your first diagnosis was that the chain was hitting the crank arm. An impossibility in most people's eyes and experience. You've then gone on to suggest other things being the cause. You're obviously navigating in a sea of fog, with no map, compass or radio comms.

cougie

How are you fixed for sorting out Brexit ?

keef66

Could it be the chain hitting the chainstay? I get that on both bikes but it makes more noise on the alu than the carbon. Tends to be in higher gears, so less chain tension, and on rough road surfaces.

Not sure that fits with your saying it happens when you get out of the saddle though...

Is the cassette lockring properly torqued up? You tend to put more strain on the drivetrain when you're standing on the pedals and giving it some welly. Mind you, would that keep on happening??

Did this noise start happening only after the new chainrings etc were fitted? Is it definitely a 10 speed chain? Do you feel any skipping or jumping or is it just making a noise?

martziniuk

I haven’t finished with the bike yet, I posted with the hope someone with a similar issue had sorted it easily without me having to troubleshoot too much. Obviously no one has come across this problem so I will investigate further.
Thanks for every constructive comment.

martziniuk

keef66 wrote:

Could it be the chain hitting the chainstay? I get that on both bikes but it makes more noise on the alu than the carbon. Tends to be in higher gears, so less chain tension, and on rough road surfaces.

Not sure that fits with your saying it happens when you get out of the saddle though...

Is the cassette lockring properly torqued up? You tend to put more strain on the drivetrain when you're standing on the pedals and giving it some welly. Mind you, would that keep on happening??

Did this noise start happening only after the new chainrings etc were fitted? Is it definitely a 10 speed chain? Do you feel any skipping or jumping or is it just making a noise?

The cassette ring is well torqued up, I made sure of that. There is no skipping or jumping, just this noise when I’m out of the saddle and the bikes swinging from side to side. I’m unsure if the issue started before the cassette change as when I bought the bike I replaced the rings, chain and cassette due to wanting a fresh start, and it was skipping gears slightly.
I need to do a bit more investigation when I get time, just thought someone might have come across the noise before.

Thank you for your reply.

Ben6899

I'm working at home today, just making a cuppa and my bike is on the turbo. So I put it in 53/11 out of curiosity from reading your question. That's the closest the chain gets to the crank arm in normal use.

Consider the tension in the chain, the chance of the chain "swaying" and hitting the crank arm in normal use is vanishingly small.

Are you sure the chain isn't way too long?
Are the chain rings bent or not fully tightened to the crank spider?

webboo

If it only happens when out of the saddle, maybe it’s coming from your bars or the front wheel.

Wayne Plunger

Might be your keys in your back pocket.

Some years back a bloke brought his car into the garage for a "clunking noise" from the rear.

We fixed it by taking his crown green bowls out of the boot!

pinno

If the chain is hitting something, somewhere, it will make a mark.
Is there any flex in the BB? Is there something moving under pressure because it's loose (well, not tightened enough)?
Is there a connecting pin on the chain protruding? You can have one marginally out - towards the chainstay, rather than the wheel and yet still get good gear shift.
Is the 'chinking' regular or intermittent?
Is it a loose chainring bolt?
Is the chainset spider/chainring bent? Non sequential tightening can cause this.
Take the front mech off, put the chain manually on to the big chainring, does it still make a noise?
The angle of the front mech, or at least, the position of the cable end changes when the front mech is pushed over, is the cable protruding so that it comes in contact with the chain/something when in the big ring?