Optimising my chain line

[Custom24]

Never heard of cross chaining?

Yes, I know what it is, but it's not relevant here, thanks.

 

[Custom24]

Last night I dismantled the rear derailleur.
No grit, fairly clean, seemed well lub'd (now spotless and GT85'd)

Jockey wheels spin fairly freely. If I flick them, they spin for a second or so and then stop with a slight whispery rub. They are not on bearings, so I wouldn't expect them to spin much longer than that? The top one, which has an integrated metal tube as well as a pop out metal tube, spins longer than the bottom one, which only has the pop out metal tube. As far as I can tell, the side metal "plates" don't spin at all, and just rub against the spinning jockey wheel. Is that normal?

Both sides of derailleur cage straight, as well as I can detect using a metal ruler in both axes.
Metal ruler also shows that jockey wheel edges are in line with each other along the long axis of the cage. Can't say about the short axis - can't see visually.
Assembled correctly (the lower wheel is marked "tension wheel" and has a directional arrow that is correct)
Chain is not rubbing or in contact anywhere I can see. There is wear on the connecting "bridge" from the 15 miles I cycled with the chain routed wrong. There is also unexplained wear at the top of the outer jockey wheel cage. This may be from the same incident. The chain is not rubbing there now.
There is, I think, daylight between the chain and the neighbouring cassette sprockets. I don't have feeler guages. Maybe a set would be useful.

Problem noise persists.

However, while osbserving the chain and rotating the cranks forwards slowly, it may be that the links are not quite centered on the bottom jockey wheel, and in "slow motion", I think I can see the chain being sort of pushed sideways by this bottom wheel as it meets each link. Also, at normal speed, the noise appears to be coming from the bottom jockey wheel by ear and feeling for vibration. It's hard to say.

My plan now;
1. Get the bike back on the work stand and try to verify where the noise is coming from using a microphone.
2. Order rear hanger alignment tool and check/adjust. Also order a set of feeler guages and check that the chain does have some daylight to the neighbouring sprockets.
3. If still problem, order new rear dearailleur and hanger.

On this morning's ride, I didn't really notice the noise while riding, so it may be better than it was.

 

[Custom24]

grasping at straws here

bought a NOS chain
chattering noise
it was hitting the adjacent teeth on either side of the cog it was on... IYSWIM
bought KMC Z7 chain [recommended by Pat]................silence
using digital calipers , it was slightly thinner

Thanks. What's NOS?

 

[John the Canuck]

NewOldStock

denotes unsold old stock - sometimes found when a shop closes down
this seller did warn me that 'older' 5speed chains could be wider

he was right............ in the bin...

 

[RecordAceFromNew]

However, while osbserving the chain and rotating the cranks forwards slowly, it may be that the links are not quite centered on the bottom jockey wheel, and in "slow motion", I think I can see the chain being sort of pushed sideways by this bottom wheel as it meets each link. Also, at normal speed, the noise appears to be coming from the bottom jockey wheel by ear and feeling for vibration. It's hard to say.

My plan now;
1. Get the bike back on the work stand and try to verify where the noise is coming from using a microphone.
2. Order rear hanger alignment tool and check/adjust. Also order a set of feeler guages and check that the chain does have some daylight to the neighbouring sprockets.
3. If still problem, order new rear dearailleur and hanger.

On this morning's ride, I didn't really notice the noise while riding, so it may be better than it was.

I haven't noticed anything strange in your report. In case it helps there should be a gap of 6.3mm between every 2nd sprocket for the chain to fit, so only about 0.3mm gap shared by 2 sides if the chain is 6mm wide.

I think looking at an M10x1mm axle in the hanger from behind and from above when the bike is vertical on a stand should tell you reasonably whether your hanger is bent.

It might be worth checking the hub. The cassette should have no play against the locknut and freehub. A new freehub should have no play (except can spin in one direction) against the hub shell. The hub shell should have a little play and spin very smoothly and freely against the axle when out, and nearly as freely but no play when on (with a tight QR skewer).

 

[Custom24]

I haven't noticed anything strange in your report. In case it helps there should be a gap of 6.3mm between every 2nd sprocket for the chain to fit, so only about 0.3mm gap shared by 2 sides if the chain is 6mm wide.

I think looking at an M10x1mm axle in the hanger from behind and from above when the bike is vertical on a stand should tell you reasonably whether your hanger is bent.

It might be worth checking the hub. The cassette should have no play against the locknut and freehub. A new freehub should have no play (except can spin in one direction) against the hub shell. The hub shell should have a little play and spin very smoothly and freely against the axle when out, and nearly as freely but no play when on (with a tight QR skewer).

Thanks for persevering with me!

In terms of chain on sprockets, I think you are saying that I expect a feeler guage of 0.15 mm to just about fit through the gap between the chain and adjacent sprockets. I guess a more important question is - what is the minimum distance there should be between the chain and adjacent sprockets to avoid a problem.

The axle in hanger did show some out of alignment as I mentioned before, but only from behind, not from above. I did think I could improvise a hanger alignment tool by attaching something to the axle, at right angles, which could spin around. But I think that would essentially be pointless and maybe misleading. Wiggle have a tool for £25.

I think the last part of your post goes as follows?
1. Remove chain.
2. Try to move cassette sideways. There should be no play.
3. Remove wheel, lockring and cassette.
After that, I'm a bit confused. I'm familiar with replacing a freehub (I've done it before), just not sure what you mean by "hub shell"

 

[RecordAceFromNew]

Thanks for persevering with me!

In terms of chain on sprockets, I think you are saying that I expect a feeler guage of 0.15 mm to just about fit through the gap between the chain and adjacent sprockets. I guess a more important question is - what is the minimum distance there should be between the chain and adjacent sprockets to avoid a problem.

The axle in hanger did show some out of alignment as I mentioned before, but only from behind, not from above. I did think I could improvise a hanger alignment tool by attaching something to the axle, at right angles, which could spin around. But I think that would essentially be pointless and maybe misleading. Wiggle have a tool for £25.

I think the last part of your post goes as follows?
1. Remove chain.
2. Try to move cassette sideways. There should be no play.
3. Remove wheel, lockring and cassette.
After that, I'm a bit confused. I'm familiar with replacing a freehub (I've done it before), just not sure what you mean by "hub shell"

Hi I don't think a 1.5mm feeler guage will do you any good. The reason being the chain can move sideways around the sprocket teeth (because the chain internal gap is wider than each sprocket), so the actual gap between the outside of the chain and the next sprocket is a variable. I don't actually think this is the issue - you definitely have the correct chain*, and I don't think you have the wrong cassette or that it has faulty spacing (since your problem is not restricted to a particular sprocket)... so what is there to go wrong and fix?

Regarding checking your wheel, you don't need to remove the chain, all you need to do is to remove the wheel from the bike as if you had to change the tyre. The hub shell is the alloy body where the spokes attach to. My suggestions above will check every interface between the movable parts, just in case any is faulty or has been badly adjusted and has unwarranted play.

* assuming it is unlikely you have TWO faulty chains

 

[Custom24]

It might be worth checking the hub. The cassette should have no play against the locknut and freehub. A new freehub should have no play (except can spin in one direction) against the hub shell. The hub shell should have a little play and spin very smoothly and freely against the axle when out, and nearly as freely but no play when on (with a tight QR skewer).

So, is this right?

1. Remove wheel
2. Try to move cassette sideways (inboard/outboard). There should be no play.
3. Remove lockring and cassette.
4. Should be no side to side movement of freehub (inboard/outboard movement)
5. Freehub should spin in one direction only.
6. Axle may have a little play with wheel out. Wheel should spin very freely. Similar to when I've adjusted cup and cone bearings in the past (although these are sealed cartridge bearings)
7. Put back wheel in bike, tighten skewer (mine is a security skewer, not a QR one, but similar). Wheel should now have no play on axle at all. Should spin freely, though. Easier to do with chain off I've found.

Thanks

 

[RecordAceFromNew]

So, is this right?

1. Remove wheel
2. Try to move cassette sideways (inboard/outboard). There should be no play.
3. Remove lockring and cassette.
4. Should be no side to side movement of freehub (inboard/outboard movement)
5. Freehub should spin in one direction only.
6. Axle may have a little play with wheel out. Wheel should spin very freely. Similar to when I've adjusted cup and cone bearings in the past (although these are sealed cartridge bearings)
7. Put back wheel in bike, tighten skewer (mine is a security skewer, not a QR one, but similar). Wheel should now have no play on axle at all. Should spin freely, though. Easier to do with chain off I've found.

Thanks

Pretty much but you don't need to remove the lockring/cassette from the freehub. So:

1. Remove wheel
2. See if there is any movement between cassette sprockets and the lockring* - there should be none and this checks the lockring is doing its job
3. See if there is any movement between cassette/lockring and hub shell - apart from it can spin there should be none - this checks the freehub internal bearings
4. Didn't know you have cartridge bearings - in that case there might be no play between axle and hub shell with wheel in and out - this checks the hub bearings

 

[Custom24]

Have just checked it.

The only play I could find was tiny, and was related to the cassette sitting on the splines of the freehub. I removed the cassette to verify that the freehub body itself has no play against the hub shell.

There was grease inside the lockring. It was all nice and green and clear. However, I accidentally got some dirt in it, so I removed it all and replaced with some waterproof chandler's marine grease I use on the MTB. I think the viscosity is slightly higher with the marine grease. Do you think that matters? Apart from that, at the moment, I only have Lithium Molybdenum and Copper grease, and I don't think either of those are suitable.

The only other thing I noticed is that the noise improves if I pivot the derailleur forward to make the chain droop. It becomes almost silent when the chain has significant droop. I am not sure what this tells me, if anything.

Going back to the alignment, I might try again. I didn't remove the mudguard the last time, so sighting for alignment from above the bike was possibly misleading.

 

[RecordAceFromNew]

The only other thing I noticed is that the noise improves if I pivot the derailleur forward to make the chain droop. It becomes almost silent when the chain has significant droop. I am not sure what this tells me, if anything.

That the noise comes from the chain meeting the jockey wheels, not the cassette. Chain tension on the cassette is driven by the chainset and little affected by sprung rear mech.

 

[John the Canuck]

................., I only have Lithium Molybdenum and Copper grease, and I don't think either of those are suitable.....................

i read the other day that lithium based tend to absorb water and should not be used for BB

i use ''Rock and Roll Web Grease' on all bearings
and CopperEase on things like stems, pedals

 

[Custom24]

i read the other day that lithium based tend to absorb water and should not be used for BB

i use ''Rock and Roll Web Grease' on all bearings
and CopperEase on things like stems, pedals

I'm kind of happy because here the grease was just being used as an extra waterproof seal, not directly as a bearing grease (these are sealed cartridge bearings according to Whyte's site). So I think a waterproof grease was a good choice and the viscosity doesn't matter too much.

Copper grease I use where there is a danger of components corroding to each other (like pedals into cranks). Also apparently good for back of brake pads to reduce squeal, but I've never used it for that.

 

[Custom24]

Another update.

I thought I had it tonight, but no.

Microphone seemed to indicate noise coming from top jockey wheel, which surprised me, as I thought it would be the bottom one.

I had another look at the alignment with the mudguard off from the top of the bike. Using a metal ruler to line up between the ends of the security skewers, it seemed the the axle I'd screwed into the hanger thread was about 5 degrees forwards, towards the front of the bike. Aha!, I said. I tweaked it so that the axle was in line, but now the noise is slightly worse, if anything. Doh!

I still think my plan above is valid. Get tool. Tool only aligns hanger, not derailleur, so if this doesn't fix it, get new derailleur and possibly new hanger once sorted.

My idea is that with ten speed, it might be that the axle method isn't accurate/sensitive enough. I've found a video on t'Internet of a guy showing how to use the tool and he says that even on new quality bikes, the alignment can be out.

Thoughts? The only other thing I can think is that I could replace the jockey wheels, but I'm not sure why that would make any difference.

Any ideas on which brand of tool?

http://www.wiggle.co.uk/lifeline-derailleur-hanger-alignment-tool/
http://www.wiggle.co.uk/cyclus-gear-hanger-alignment-tool/
http://www.chainreactioncycles.com/park-tool-mech-hanger-alignment-tool-dag2/rp-prod35945

The lifeline one is cheapest but has decent reviews, but is unfortunately out of stock. The Cyclus one has some bad reviews. The Park Tool one is a bit more but is probably what I'll end up going for.

 

[Custom24]

Hi
Another update.

I decided to go back to the shop, explaining that I still wasn't happy.

They checked alignment of hanger - spot on. doesn't seem right because they also said they did this the last time and I subsequently tweaked it...

They also swapped the derailleur for a brand new 105 long cage. They said that the top jockey wheel on the old one was noisier than they would like. I am not sure why they went for a long cage - they said something about it being a better match for the cassette. Maybe it was all they had. They said there is plenty of slack in the chain and the big/big forbidden combination is fine - I checked.

Problem is - noise is unchanged. I can't believe it. I told them this in the shop but I can't see what else they could do.

I think at this stage I will live with it. Maybe it's just how the bike sounds. At least I didn't waste money doing the same as they did for free, and still ending up with the noise.

I am half tempted to still buy the tool because something about it doesn't add up, but I will leave it a few weeks and see if the noise is still bothering me.

Thanks for all you help.