Rear Gear Calibration; ahhhhhhhhhhhhhhhhhhhhhhhhhhh!

[Philip Whiteman]

Advice sought:

Can rear derailleur springs weaken and can they be the cause of poor calibration?

For the past few months my Orbea has been a complete pain as the rear shifts become progressively worse. Despite checking the stops and going through the usual procedure (see Youtube clip below), I still cannot get the Shimano 105 10 speed gears to shift as I would like. When I manage to stop the chattering at one end then it becomes worse at the other, or vice versa. I have no such problems with our other bikes.

This afternoon,
i. I removed the rear derailleur and deep cleaned it;
ii. replaced the cable;
iii. checked outer cable housing;
iv. replaced a slightly damaged ferrule;
v. went through the usual procedure of tensioning cables, etc.

The bloody thing still does n;t work!

(Paul, this time the bike was positioned differently on the stand to ensure that cables were not compromised).

Youtube clip: http://www.youtube.com/watch?v=SkzvfCaIbyQ

[AlanW]

My first question would be, did you replace both sections of the outer cable liners as well as the inner cable?

[Philip Whiteman]

My first question would be, did you replace both sections of the outer cable liners as well as the inner cable?

No, just the inner cable. The outer cable looked fine and there was no metal from the liner fouling the inner cable at the ends.

[AlanW]

My first question would be, did you replace both sections of the outer cable liners as well as the inner cable?

No, just the inner cable. The outer cable looked fine and there was no metal from the liner fouling the inner cable at the ends.

IMHO, unless you replace both the inner and the outer then you are wasting your time. Especially the shorter outer cable by the rear mech, it is the outer liner swelling internally that can cause many shifting problems.

Tight arse..................

[Philip Whiteman]

Thanks Alan. I may well do that.

However, just to clarify. It is not resistance in shifting, rather the calibration and alignment of shifting from ring to ring. Hence the chattering. Can that still be related to the outer cable swelling?

Incidentally, I washed out the upper out cable and there was no effluent. However, there was quite a bit of dirt that appeared from the rear/lowest cable.

I also guess that you doubt the explanation in terms of the spring.

[AlanW]

Thanks Alan. I may well do that.

However, just to clarify. It is not resistance in shifting, rather the calibration and alignment of shifting from ring to ring. Hence the chattering. Can that still be related to the outer cable swelling?

Incidentally, I washed out the upper out cable and there was no effluent. However, there was quite a bit of dirt that appeared from the rear/lowest cable.

I also guess that you doubt the explanation in terms of the spring.

Yes, the resistance in shifting can ultimately affect the calibration. I would not expect to see much debris come from the liner to be honest.

I also doubt, but it is possible, that the spring has weakened in the rear mech.

Another area to look at carefully are the bushes in the rear mech, especially if you have been cleaning the rear mech with a degreasing agent, such as Muc Off. This truly awful product will seep into flipping everywhere and over time will wash out the grease and will cause you problems, such as the rear mech sticking or operating at random distances.

Have you also checked the play in the jockey wheels, as these can give you similar problems with shifting, especially the upper one of the two.

[Pedlo Mudguardo]

Is the problem changing to a higher or lower gear generally ?

[John Sanderson]

I am currently experiencing similar problems. As Alan has suggested. I suspect that problems (e.g. dirt and or corrosion) relating to the pivots on the mech are much more likely than a weaking of the spring - assuming that you always relax the tension on the derailleur when the bike is parked? It's something i've taken for granted but come to realise plenty of people don't bother to do...

[AlanW]

- assuming that you always relax the tension on the derailleur when the bike is parked? It's something i've taken for granted but come to realise plenty of people don't bother to do...

I have to say that I always leave my bikes overnight with no tension on the gear cables, another sub section of my OCD I'm afraid.

But your right, not many people do it or even understand the reasons why you should.

[Philip Whiteman]

Is the problem changing to a higher or lower gear generally ?

Changing from low (large sprocket) to high, usually around the third of fourth in. But to be honest this can change depending upon how I compensate with tension adjustment. If I correct the higher end then the lower end becomes a problem or vice versa.

- assuming that you always relax the tension on the derailleur when the bike is parked? It's something i've taken for granted but come to realise plenty of people don't bother to do...

I have to say that I always leave my bikes overnight with no tension on the gear cables, another sub section of my OCD I'm afraid.

But your right, not many people do it or even understand the reasons why you should.

To be quite honest, that is the first time I have heard of this but I can quite understand why. In reality and by default, when I arrive home my rear gear cable is usually on the small sprocket.

[George]

I think that all systems gradually become less precise over time, due to slight wear and tear to all moving parts. If there's a tiny bit of play in the lever's ratchet mechanism and a few points where the cable is slightly kinked or dragging on the outer, etc, etc, it adds up to noticeably imprecise shifting. The more you ride, and crappier the roads you ride on, and the less well engineered the system was in the first place, the faster the deterioration.

Replacing any part of the assembly will probably help, but you'll never regain perfection without replacing the lot. That said, I've found before now that a new set of cables and/or new levers plus an old-ish derailleur gives a nearly new feel, but the opposite combination (a new derailleur with old-ish levers/cables) still feels crap.

I would imagine that regular cleaning helps to slow down the process, but I have no personal experience of that.

Also, where the front mech is concerned, slight misalignment relative to the rings can have a major impact. If a mech is giving me problems, that is one of the first things I look at.

[GrahamGamblin]

When this happened to me recently (very similar symptoms to Phil's) it turned out to be a worn chain and sprockets. I too spent ages trying to sort out the indexing, and I was looking at the wrong problem.

[John Sanderson]

Ah yes - for me first stop with a badly shifting drivetrain is usually 'clean the chain'!!

In truth i've often thought that cycling as an activity could just as easily be rebranded 'chase the squeak'... My favourite recent experience has been replacing the bottom bracket in attempt to resolve the squeak which was finally traced to the saddle rails...

[Philip Whiteman]

In this case, the chain has not reached .75 of wear and it is very clean. So no problem there.

[AlanW]

In this case, the chain has not reached .75 of wear and it is very clean. So no problem there.

But what about the cassette?

[Philip Whiteman]

In this case, the chain has not reached .75 of wear and it is very clean. So no problem there.

But what about the cassette?

That was changed at the same as the chain

[jonnyri]

Quite often cables. Also check hangers not misaligned.

[Bagbear]

My mate has had a similar problem recently....after changing the cable and cleaning it was no better. Tried another wheel and cassette but still no luck. Finally changed the derailer itself and the issue is still there!!

Set it up correctly and after moving up and down a few times it starts to skip.

I can only think its the sti shifter! Now have to swap that and see it it solves the issue.

Its almost as if the sti isn't pulling the cable in a consistant way - especially on the way down (to the smaller sprocket)

[dweben]

I've always found most shifting problems are down to the outer hoses. Imo there's bugger all point changing the cables without doing the hoses too unless it's just frayed dry cables. They get clogged up with crap lube, mud, bits of cable, etc. Sometimes the end caps get worn down and distort, the hose metal weave can wear and split, jamming cables, etc. It's also the cheapest place to start. Make sure the loop onto the rear mech is big unless it's a direct pull shadow mech which I don't think roadie bikes have (my mtb has one).

Once the hoses are done then you can look at the mech, just remove it and make sure it's clean and lubed. Put back on and check it moves the full range. Set up and lower, then tune the middle a touch.

Shifters really don't wear out much. They're away from muck and just last years... doubt it's there. Unless the shifters are not shimano shifters it shouldn't be the issue. I'd check this last as it's a) expensive and b) a bugger to swap over.

Of course the other way to check the rear mech is to pull a fully working mech off another of your wilderbeasts and swap it out.

You've had issues with spacers in the cassette before? Maybe an idea to pop the cassette off and ensure all the rings and spacers are on the freehub in the correct order! Maybe check the freehub bearings by wobbling it about a bit to see if there's play. (unlikely this is it)

Setting up
a) don't clamp the cable in the bike stand clamp... PHIL
b) pre tension the cables before tuning
c) tune up/lower
d) mech should be setup, but can be tuned with the knobbly bit
e) have you tried tuning up by the shifters? can you?

f) sometimes if you have the front mech positioned wrong it can pull the chain over when crossing the front/rear rings.

Err ok running out of tech ideas now... mostly from muddy winter mtb riding experience.

Paul

[snailmale]

I allus said we'd come to regret it when we abandoned the Cyclo Benelux 4 speed

[George]

Don't worry. In another few years, we'll all be using electronic systems. There will be no gradual wear to the ratchets in your levers. And no cables to get kinked, frayed and gunked up.

Instead, every couple of years, your gears will suddenly and inexplicably stop working. Probably when you are half way up a hill, fifty miles from home. Following your rescue, you will quickly establish that you are powerless to resolve the problem yourself, and will be obliged to take the bike to a shop. There, a spotty youth will attach a computer (a process which will cost you £50) and tell you that the XYZ chip needs replacing (which will cost you even more).

[Philip Whiteman]

And the verdict........











....Shimano compatible products do not make them compatible with each other. My chain drive was using a BBB cassette with Wippermann chain. This combination was the cause of my problems despite both being well within wear tolerances.

It took a lot head scratching a Cultracing to diagnose the cause of the problem. Anyway, the bike now has a genuine Shimano chain and cassette and is working fine.

So the essence of the story, do not trust Shimano 'compatible' products.

[AlanW]

And the verdict........











....Shimano compatible products do not make them compatible with each other. My chain drive was using a BBB cassette with Wippermann chain. This combination was the cause of my problems despite both being well within wear tolerances.

It took a lot head scratching a Cultracing to diagnose the cause of the problem. Anyway, the bike now has a genuine Shimano chain and cassette and is working fine.

So the essence of the story, do not trust Shimano 'compatible' products.

Now had you have mentioned that detail in your orignal post then I would have told you the exact problem. Having gone down the exact same route myself a numbers of years ago with a BBB cassette, only to discover exactly what you have.

[Oscar]

Strange I have had similar problems and the bike has only done 30,000 miles.

[snailmale]

Strange I have had similar problems and the bike has only done 30,000 miles.

Oscar, Can't you ask Nita to get a part-time job so that you can buy some top-of-the-range replacements?