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Shimano drivechain help required
#1
I have a 2011 specialized secteur that came with sora groupset on it.
I always keep my bike properly cleaned and lubed.
recently my chain started skipping round every so often on certain gears when I push hard through the pedals such as hill starting, but this would also happen randomly mid pedal strokes, say on the flat. I messed with cable tension and new cables etc but no joy and the cogs started to show signs of being damaged.

I checked with the chain wear indicator and it wasn't yet even worn to 0.75 but I made the decision to replace the 9 speed hyperglide hg50 cassette, 9 speed HG93 shimano chain and chain rings. I replaced like for like, however the problem is still there! with brand new compatible drive chain components too! I might add also that the skipping / tripping of the chain is happening on most cogs and appears not to skip onto other cogs when the problem occurs.
Checks I have now made are:
1. Hanger is perfect.
2. Dropouts are fine and wheel sits in dead straight every time.
3. pulley wheels on Tiagra rear mech are in good condition and rear mech is in good condition
4. no stiff links detected in chain
5. gears indexing well.
Any ideas appreciated before my new drivechain components get trashed!! I was thinking perhaps the FH-2200 freehub is worn but I've only been riding the bike for about 9 months and I've had similar freehubs last years longer. plus it is my understanding that freehubs are 'all or nothing' i.e. they completely malfunction and it is conclusive rather than partially malfunction under pressure like my problem - please correct me if I'm wrong.
Should I try a more expensive cassette? can you recommend one?
Cheers,
Tim
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#2
Double check chain length - probably fine.

I would look at the RD's spring.

Regarding cassettes - more expensive = lighter; not better functioning. In fact quite often not function as well, and certainly do not last as long. Sunrace offers nice cassettes.

FYI - I have not had good experience with Shimano chains, and now use KMC or SRAM. Freewheels and cassettes: prefer: Sunrace, SRAM and DNP (cassette).
Nigel
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#3
(08-12-2014, 04:18 PM)nfmisso Wrote:  Double check chain length - probably fine.

I would look at the RD's spring.

Regarding cassettes - more expensive = lighter; not better functioning. In fact quite often not function as well, and certainly do not last as long. Sunrace offers nice cassettes.

FYI - I have not had good experience with Shimano chains, and now use KMC or SRAM. Freewheels and cassettes: prefer: Sunrace, SRAM and DNP (cassette).


Hi Nigel, thanks for posting. So how do I check the RD spring? It seems to hold the chain tension ok, but not as much as my ultegra RD on my other bike. Or do you mean the other spring that works laterally against the cable tension? Maybe it would be worth changing it for my ultegra RD to see if it solves the problem?

That's interesting about the cassettes and helps me feel less suspicious about it. Plus I feel it must be significant that the problem gradually came into existence with the old sprockets/chain/chainring (even though they did not appear significantly worn) and the same problem has continued with the new sprockets/chain/chainring

Regarding chains - The interesting thing is that I did try a brand new 9 speed KMC chain on it earlier and it didn't improve things.
But how would chain length make the it skip under pressure anyway?
I just measured it to the old one and everything seems ok when I take it to the extremes of the gear range (i.e. the RD not stretched too far out or in) but is there a more objective way of being sure?

Thanks again,
Tim
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#4
Hi Tim;

Shimano TechDocs (Google that) show Shimano's recommended chain length measurement method.

New chain should go with new cassette; unless the old chain was not worn (less than 1/16" per foot).

Swapping RDs would be a great check; I don't know another way.

If the chain is too long, the RD does not exert enough force to keep the chain firmly seated in the cog - generally the skipping will be worse in the gears where the RD has to take up more chain (smaller cogs).
Nigel
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#5
hay dumb question maybe? did you check your derailer hanger? because if ya didnt thats peobably the source of the problem..before you drive yourself crazy replacing everything else..because you can get new lines derailer, chain, gears, whatever, but if your hanger is pitched a miniscule amount in any way..it will reak havoc on your drivetrain, been there done it..ive learned always start with the simplest and cheepest things first..its usually always the culprit.
and i found when going to the smallest cog or largest cog , when the hangers bent it will cause serious chain jump and binding..like when ya pedal backward it will skip sortof and bind the chain up..and going forward it will jump gear or refuse to shift a gear..or even lazy shift, like you triggered for the next gear and it doesnt shift expectadly..
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#6
(08-25-2014, 01:08 AM)tourgee07 Wrote:  hay dumb question maybe? did you check your derailer hanger? because if ya didnt thats peobably the source of the problem..before you drive yourself crazy replacing everything else..because you can get new lines derailer, chain, gears, whatever, but if your hanger is pitched a miniscule amount in any way..it will reak havoc on your drivetrain, been there done it..ive learned always start with the simplest and cheepest things first..its usually always the culprit.
and i found when going to the smallest cog or largest cog , when the hangers bent it will cause serious chain jump and binding..like when ya pedal backward it will skip sortof and bind the chain up..and going forward it will jump gear or refuse to shift a gear..or even lazy shift, like you triggered for the next gear and it doesnt shift expectadly..

Hey, thanks very much for the input.
I did take the bike to a shop and they solved the problem or so it seemed by tightening the gear wire. However they didn't test ride it properly and although it seemed ok when I rode it a little outside the shop, the problem later started up again although admittedly it was not as bad as before it went into the shop.

I noticed that they had tightened the cable quite a lot, such that it felt like a guitar string even in the smallest sprocket.They said that it can be a tricky job getting the cable tension right and that it takes experience, but my understanding is that after you pull the cable 'finger tight' with the drailleur in the smallest cog position, then you tighten the clamp bolt on the derailleur and index the gears using the barrel adjuster. Please correct me if I'm wrong..
Howevero, thinking that they had perhaps got the tension into the right region I started to turn the barrel adjuster a quarter turn between each test ride, however yet again the problem did not resolve and my chain actually snapped.

In regard to the hanger - again, it seems fine and straight to me but from what you are saying it sounds like even very slight / imperceptible distortion of the hanger might be causing this problem?? I was about to buy a new derailleur but would it be worth trying a new hanger even though it looks ok?

Thanks again,
Tim
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#7
i would try a new hanger, but if you want to check the hanger for trueness..if you line up the wheels from the derailer under the smallest cog they should run perfectly straight underneath the cog, viewing it from the back, most times if they are angled you can bend the hanger using an adjustable wrench, back to true. but if you feel sketch in doing so, because the hanger could snap..and if you can afford it i would get a new hanger..my friend took his specialized to a shop because he was having issues, he rhode it outside the shop, it felt fine..he took it trailing and all the issues were still there, so he changed just about everything, and nothing helped, he gave iy to me as a last resort, and after checking it out, I found the hanger was bent, i straightened it and changed the cable, re adjusted it and its been great sense."sometimes its the smallest overlooked things that make the biggest difference" let me know how it works out..good luck
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#8
most times its usually a hanger issue, or if the cable housing is frayed going into thr derailer it will cause issues, i usually ride single gear..but i got a nack with geared bikes..u would deffinately try a new hanger, its cheeper than a derailer and I'm 98% sure that will fix your issue!
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#9
even replacing the hanger ,you still need to check and adjust with a Derailleur alignment gage
There are two kinds of people in the world, "Those who help themselves to people, and those who help people!"
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#10
(08-28-2014, 12:32 AM)painkiller Wrote:  even replacing the hanger ,you still need to check and adjust with a Derailleur alignment gage

cheers guys, finally feel like I'm getting this problem narrowed down. I did take a photo to but im on my phone so cant upload, however its probably one of those things that is hard to decipher from a photo anyway.

So, i think my plan is to try and borrow a derailleur alignment tool to then replace or straighten the hanger if indicated.

I'll keep you posted..
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#11
Hi,
So the latest is I've acquired a derailleur hanger alignment tool and sorted a slight discrepancy out. The problem resolved slightly but still did not go away.
Next I changed the rear mech for one off another road bike that I've never had problems with - problem still did not resolve.
Thinking it might be a dodgy freehub body, I put a different back wheel on from my new trek bike (bontrager race) - problem still there!
The situation is not as bad as it has been but the chain still slips and skips when I push hard in the lowest gears on the bike - I dread steep hill starts out of the lights cos I know the chain will probably slip and I'll be on the floor if the chain snaps.

Although the shifters are barely a year old in terms of usage (they are 2012 or 2011 edition Sora 9 speed) I noticed it was nearly impossible to get the indexing right on all gears for instance the first click from smallest cog wouldn't jump it to second cog, I had to click it twice no matter how much tension I put on the cable , but aside from that, when I got it shifting up every other cog with a single click, I found it would not skip down in the same mannner - so turn the barrel adjuster gradually in to gradually take off tension until it skips down each cog right? well by the time it was shifting down well, it would not shift up properly and vice versa - impossible to get the sweet spot where cable tension shifts up and down every cog with a single click of the shifter. So now I'm thinking it MUST be the shifters or the shifting cable circuit right!!??? So I've bought new 9 speed shifters that are on the way..

Though if it is the shifters - how would this create the problem in the lowest gears!??

Thanks for reading. Input appreciated as always.
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#12
The skipping could be a worn front chainring. A lot rarer than a worn cassette, but it does happen. Does the skipping only happen if you're in the small in the front, just in the big, or in either?

The shifting problem still sounds like a bent hanger. New shifters may help, but that seems a little odd. I would check your cables and housing carefully. A bad piece of housing could cause this if it isn't seated well into the cable holder, if it's pulling through the ferrule, or even if someone used a piece of brake housing instead of shifter housing.

tough one...
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#13
Hi, thanks for the reply and for sticking with it!
I have inspected the chainrings and i am confident they are true and unworn. Initially the skipping was occurring mostly in the middle chainring (but that's probably because i hardly ever dropped to the small) so i replaced the middle with a new one as i did detect some butted up teeth (due to the heavy slipping i presumed), however this did not resolve it so i also replaced chain and cassette which didn't work either.

now i have moved to the top of a great big hill and i need to use the small chainring however it is quite unworn due to lack of use. The problem does occur in both small and middle chainrings when i am pushing hard through the pedals and in the lower gears. Standing up out of the saddle is the worst and setting off from a hillstart. It is a little worse when in the small chainring though but i think this is more to do with the fact that i rarely go into the two lowest sprockets when in the middle chainring in order to avoid cross-chaining. So it does appear to be something that happens as the rear cassette gears get lower. Also, Just when I think I'm getting away with it, if I go over a bump or pothole this will initiate the problem, as though the derailleur is less stable when up in the lower gears and it gets easily upset by the bumps..

The hanger is now perfect and the the sprokets look as level and in-line as they possibly can be. The chain does not look angled and there is no chain rub evident. There is of course a very slight angle created by the accumulation of slight flex throughout the derailleur joints - I've noticed this on all derailleurs apart from the very highest spec ones.

I hadn't thought of the cable circuit purely because i used the bike from new and it didn't have this problem for the first 8 months or so and i keep it well maintained, lubed and inspected. That being said, i will now replace all the cable housing, wires and ferrules and let you know the outcome. Any other ideas welcomed as always.

many thanks
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