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Shadow Rear Mech - Chainsuck Hell

ilikebikes73ilikebikes73 Posts: 11
edited September 2010 in MTB workshop & tech
Spent the last few weeks trying to sort out problems with chainsuck after an hour or so's riding in summer conditions (occasional puddles and a little mud). Chainrings were a couple of years old so changed em which helped. Old chain was only 0.5% worn but changed it anyway. Still the same problem. Better but but was still getting problem when dropping from middle to granny ring. Shortened chain to be 1 full link less than the various guidelines but problem persisted. Only sorted the problem when I changed my newish Shadow rear mech for a "regular" model. My assumption is that the shadow is not capable of taking up chain slack quick enough to take up chain tension following a downshift because it only has a single tensioning spring rather than the usual two. I hope this helps other people with their choice of deraillure !

Posts

  • AnonymousAnonymous Posts: 79,667
    Nonsense. Shadow is perfectly capable, and in many people's experiences is actually better than the standard mechs.

    My guess, if the mech is what caused/solved it, it a sticky jockey wheel, or some damage to the pivot.
  • DickBartonDickBarton Posts: 201
    Hmmm, not sure if it would be the shadow mech unless it was damaged - has it been knocked? Shadow mech does tend to work very well and from the experience I've had with them and those of my mates they don't work any slower than a normal mech...

    How long is your chain? I run a very short chain on my bike and never suffer a problem (but I also run a shorter caged rear mech wihcih I think can also help BUT does mean gear choice needs to be thought about rather than just bumped in).
    The Quest for Singletrack is Endless...
  • nicklousenicklouse Posts: 50,675 Lives Here
    have a read all about chainsuck http://fagan.co.za/Bikes/Csuck/

    were you actually suffering with chain suck or was it something else.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • clantonclanton Posts: 1,288
    yeehaamcgee wrote:
    Nonsense. Shadow is perfectly capable, and in many people's experiences is actually better than the standard mechs.

    My guess, if the mech is what caused/solved it, it a sticky jockey wheel, or some damage to the pivot.

    Just to disagree with the above - functionally the Shadow is fine but the small metal plate that connects the bolt into the hanger to the rest of the mech is way too weak. If you smack these mechs that plate snaps rather than the hanger bending.
  • AnonymousAnonymous Posts: 79,667
    :roll:
  • Chunkers1980Chunkers1980 Posts: 8,035
    clanton wrote:

    Just to disagree with the above - functionally the Shadow is fine but the small metal plate that connects the bolt into the hanger to the rest of the mech is way too weak. If you smack these mechs that plate snaps rather than the hanger bending.

    Yes that *may* be true - but you can replace it.
  • clantonclanton Posts: 1,288
    Chunkers1980 wrote:
    clanton wrote:

    Just to disagree with the above - functionally the Shadow is fine but the small metal plate that connects the bolt into the hanger to the rest of the mech is way too weak. If you smack these mechs that plate snaps rather than the hanger bending.

    Yes that *may* be true - but you can replace it.

    Interesting. I had a look at it and concluded it was an integral part of the mech body and not replaceable as a seperate bit -so I binned the mech. If what you say is true then that may have a waste.
  • wobbemwobbem Posts: 283
    Chunkers1980 wrote:
    clanton wrote:

    Just to disagree with the above - functionally the Shadow is fine but the small metal plate that connects the bolt into the hanger to the rest of the mech is way too weak. If you smack these mechs that plate snaps rather than the hanger bending.

    Yes that *may* be true - but you can replace it.

    No you cant', happened to my XTR last year, and had to by a new one got a cheaper XT instead. Can't understand why its not sold as a replaceable part though.
    Don't think, BE:
  • Chunkers1980Chunkers1980 Posts: 8,035
    wobbem wrote:
    Chunkers1980 wrote:
    clanton wrote:

    Just to disagree with the above - functionally the Shadow is fine but the small metal plate that connects the bolt into the hanger to the rest of the mech is way too weak. If you smack these mechs that plate snaps rather than the hanger bending.

    Yes that *may* be true - but you can replace it.

    No you cant', happened to my XTR last year, and had to by a new one got a cheaper XT instead. Can't understand why its not sold as a replaceable part though.

    Not sure what you mean - it's not sold as a replacement part?
  • konadawgkonadawg Posts: 447
    Interesting about the Shadow "link plate" or whatever. That kept me away from Shadow on my latest derailleur change as I had seen more than my fair share of bent and snapped ones.

    However it would be good to know whether these are or are not replaceable parts. Some bikes of late come with "hangers" that are also integral parts of the rear suspension pivots and which really do not seem to be either very bendy or cheap to replace if snapped. Many seem to have Shadow RDs so I thought that maybe that link plate served as a deliberately engineered weak point. But replacing the RD is almost certainly costlier than even a complex hanger-cum-pivot.
    Giant Reign X1
  • Chunkers1980Chunkers1980 Posts: 8,035
    The are definately 'replaceable' it's a case of do they have a part number and can you by them as a separate item.

    For the guy that threw away his XTR shadow - RRP £170 what a waste - hope you took par tof the carbon cage off? I know the plate is slightly different in shape on the XTR from say the SLX, but I bet you can get a 590 deore to fit and work correctly and they are only 30 ish quid.
  • wobbemwobbem Posts: 283
    Chunkers1980 wrote:
    The are definitely 'replaceable' it's a case of do they have a part number and can you by them as a separate item.

    Just rechecked the parts list and there it is (no2) local bike shop told me that it wasn't replacable, luckily still got the mech and will try again.
    cheers for that

    http://techdocs.shimano.com/media/techd ... 721668.pdf
    Don't think, BE:
  • konadawgkonadawg Posts: 447
    Chunkers1980 wrote:
    The are definitely 'replaceable' it's a case of do they have a part number and can you by them as a separate item.

    Well yes that is the issue of course :wink:

    I know that for example a very common wear and tear item (Shimano hub cones) are actually listed as a spare but it all seems rather theoretical when you actually try to order one, so it's not just one hurdle but two - does it exist, and does it REALLY exist :roll:

    I bought some hangers from some guy in the states off fleabay, he apparently makes them himself, now if these r/d bits were not available it could be something to suggest he sets up for!!
    Giant Reign X1
  • AnonymousAnonymous Posts: 79,667
    Any shimano dealer (which means all decent bike shops) will be able to get you hub cones. The only place I've had difficulties getting them from was Halfords, and a local bike shop that had a reputation for being ucking fuseless
  • wobbemwobbem Posts: 283
    Update on the part number 2 for my Xtr rear mech- not available as a seperate item. :evil:
    Bike shop advised me - jokingly to go Shram. :roll:
    Don't think, BE:
  • Chunkers1980Chunkers1980 Posts: 8,035
    Buy a 590 deore
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