Bike whisperers - gather round

greg66_tri_v2.0

Right. This is distinctly odd.

I have a creaky drivetrain. It sounds a bit like the noise I had once due to a loose spider bolt. or a dying chain. Metallic creak. Gets louder under heavy load.

However, (a) it's all the way round the pedal stroke. (b) It is specific to the 15 tooth sprocket.

If I switch to the 16 or the 14, all is silent. Back the 15? It's back.

I've lubed the chain, to no effect. I've had a look at the 15 sprocket without removing it, and there doesn't seem to be any sign of a break. I'm left wondering whether the inside edge of the sprocket is doing something weird and noisy against the freehub body.

I'm struggling to work out what can cause a creak that is specific to a single sprocket.

Ideas?

Greg T

Well...

Sounds like you need a new bike

cjcp

Has the sprocket dug into the freehub grooves? Although mine didn't creak in this situation.

One of the spacers worn?

Is the wheel sitting ok in the dropouts?

MonkeyMonster

take your pedals off, clean both spindle and socket, grease and re-attach. yes nothing at all to do with sprockets but i too thought my issue was drive train. is it the sproket itself or rather chain rubbing because of the angle between big cog at front and sprockets? If you are in the smaller one up front does it still make a noise?

tgotb

Is the cassette locknut properly tightened?

rolf_f

Presumably either the specific sprocket or the alignment of the chain whilst in that sprocket.

Obviously, you should have a spare cassette anyway to be able to compare and contrast.........

Gallywomack

Obviously, you should have a spare cassette anyway to be able to compare and contrast.........

Remember to use a new chain, mind.

Torvid

5 replies in and no ones mentioned just not using that cog yet? standards are slipping.

On a more serious note what make and range is the cassette as this would be more helpful to tell if it's in the middle of a solid milled part or the breat between individual cogs or something else.

UndercoverElephant

Hmmm, does the creak happen if you are using the other chain-ring?

MonkeyMonster

UndercoverElephant wrote:

Hmmm, does the creak happen if you are using the other chain-ring?

No you see - all you've done is condensed my question down to a few words

UndercoverElephant

MonkeyMonster wrote:

UndercoverElephant wrote:

Hmmm, does the creak happen if you are using the other chain-ring?

No you see - all you've done is condensed my question down to a few words

Actually I was wondering if it was more a resonance issue, relating to the relative sizes of the big-ring 15T. If that's what you were getting at, you really are quite circumlocutory.

MonkeyMonster

UndercoverElephant wrote:

MonkeyMonster wrote:

UndercoverElephant wrote:

Hmmm, does the creak happen if you are using the other chain-ring?

No you see - all you've done is condensed my question down to a few words

Actually I was wondering if it was more a resonance issue, relating to the relative sizes of the big-ring 15T. If that's what you were getting at, you really are quite circumlocutory.

ah, i just asked in my annoyingly totally un-scientific way of "If you are in the smaller one up front does it still make a noise?"

Jay dubbleU

Chair rubbing on front mech?
Do you get the same effect on both front rings ?
Do you tend to use the 15 more than the others ?

greg66_tri_v2.0

cjcp wrote:

Has the sprocket dug into the freehub grooves? Although mine didn't creak in this situation.

One of the spacers worn?

Is the wheel sitting ok in the dropouts?

I'm thinking it might the freehub, but I can't work out why it would make this noise. Don't think it is the spacer/wheel.

MonkeyMonster wrote:

take your pedals off, clean both spindle and socket, grease and re-attach. yes nothing at all to do with sprockets but i too thought my issue was drive train. is it the sproket itself or rather chain rubbing because of the angle between big cog at front and sprockets? If you are in the smaller one up front does it still make a noise?

Don't see why pedals would go quite on the adjacent sprockets though. Haven't tried 39x15. Will do so.

TGOTB wrote:

Is the cassette locknut properly tightened?

Think so. I tightened it the same way I usually do. Have had a loose locknut before on another bike. No creaks - just chain jumping all over the place as the sprockets drift under it.

Rolf F wrote:

Presumably either the specific sprocket or the alignment of the chain whilst in that sprocket.

Obviously, you should have a spare cassette anyway to be able to compare and contrast.........

I am seriously considering a money-based solution which involves replacing both and crossing my fingers, yes.

Torvid wrote:

On a more serious note what make and range is the cassette as this would be more helpful to tell if it's in the middle of a solid milled part or the breat between individual cogs or something else.

Campy 12-25. 15 is close to straight chain line (16 is bang on). 15 is an individual sprocket.

Jay dubbleU wrote:

Chair rubbing on front mech?

Do you tend to use the 15 more than the others ?

No chain rub. Tried all sorts of trimming and makes no difference.

I only ever use the 15 in London.

SteppenHerring

Greg66 wrote:

I only ever use the 15 in London.

Maybe the noise isn't the bike - it's London.

Worth giving the seatpost a check - does it make the noise when you're out of the saddle?

greg66_tri_v2.0

SteppenHerring wrote:

does it make the noise when you're out of the saddle?

Yup.

Torvid

Greg66 wrote:

Campy 12-25. 15 is close to straight chain line (16 is bang on). 15 is an individual sprocket.

If i remember correctly campy 11spd cassettes are all individually spaced so you may well have a damaged spacer between 14-15-16, my bet would be 15-16 take the cassette off and switch the spacer off 23-25 it should be the same size. Won't fix the issue with the spacer but moves it to a less used set of cogs.

greg66_tri_v2.0

Torvid wrote:

Greg66 wrote:

Campy 12-25. 15 is close to straight chain line (16 is bang on). 15 is an individual sprocket.

If i remember correctly campy 11spd cassettes are all individually spaced so you may well have a damaged spacer between 14-15-16, my bet would be 15-16 take the cassette off and switch the spacer off 23-25 it should be the same size. Won't fix the issue with the spacer but moves it to a less used set of cogs.

Mine's a 10s. Thing about a damaged spacer is this: why wouldn't it cause a noise when either of the adjacent sprockets are in use?

Torvid

Greg66 wrote:

Mine's a 10s. Thing about a damaged spacer is this: why wouldn't it cause a noise when either of the adjacent sprockets are in use?

If it gone slightly concave it's probably free to compress in one direction but not the other this would only let the one cog move. Like i say just a guess but a quick and easy thing to check.

rick_chasey

Ride a singlespeed.

greg66_tri_v2.0

Rick Chasey wrote:

Ride a singlespeed.

I do. See above.

It's just that mine has a load of additional ironmongery hanging off the back.

rick_chasey

Greg66 wrote:

If I switch to the 16 or the 14, all is silent. Back the 15? It's back.

Say what? :P

snooks

I'm thinking it's your knees, you are old after all :P

itboffin

Does no one else see the point here? G66 is trying to tell you all he rides around all day in the 50/15T - like a man trying, really trying

greg66_tri_v2.0

itboffin wrote:

Does no one else see the point here? G66 is trying to tell you all he rides around all day in the 50/15T - like a man trying, really trying

10 points for Gryffindor!

jejv

itboffin wrote:

Does no one else see the point here? G66 is trying to tell you all he rides around all day in the 50/15T - like a man trying, really trying

Yes. I reckon that noise is his knees.

He needs something like this:

Drfabulous0

Check that your Ipod is turned up all the way