Conference noted::bicycle

    I would imagine you could change the derailleur easily. But what
    exactly aren't you happy with in your current system? Rear shifting
    problems aren't necessarily the derailleur's fault, or not just its
    fault.
    
    
    Rod

    I currently get a lot of "grinding" noise.  I have tried to adjust it
    (both myself and my bike shop) to eliminate the noise all to no avail. 
    In addition, I occationally get "skipping" when under stress; it seems
    that the chain will skip a tooth, although I haven't completely
    diagnosed that problem.  I do know that I have ridden bikes with
    enhanced componentry that are very quiet and no skipping.  I'm
    assuming, all other things being relatively static, that its the rear
    derailleur and derailleur tension.
    
    I hope this gives you enough info to let you know whether I'm attacking
    the problem incorrectly.
    
    Thanks in advance,
    
    Jack Boyle  DTN 323-4448

    Your shifting problems could arise from the chain, the gear sprockets
    or the derailleur, or rather, how they interact with each other. I'm at
    loss to suggest what actually *is* wrong, but are the components all
    Suntour, or has a cheap chain or freehweel been slipped in, and are
    they new or old? If I were you I'd investigate along these lines. 
    
    
    Rod

    The bike has only 1000 miles on it or so (less than a year old).  All
    components have SUNTOUR labels on them, except the chain which is
    unlabeled.  I assume this is stock equipment without modification.  I
    agree that the interaqction of the components is the problem, however I
    can not find any adjustments on the derailleur except 1st-last gear
    stops.  It also seems that there is too much play in the derailleur for
    not having any adjustment screws.  Anyway, the adjustments don't seem
    to help.
    
    I hope this information gives you a lead.
    
    Thanks,
    
    Jack Boyle

    I wish someone else would respond, Jack, because I'm running out of
    ways to sound knowledgeable. I would offer to come round and have a
    look if I lived near you, however I work in France, so...
    
    There was a note in here today about how to set index rear derailleurs,
    so that could help. But from what you said, your shifting problems are
    more subtle than that.
    
    I think Suntour will, this year, introduce a new kind of gear cluster
    for Accushift systems, something that will compete with Shimano
    Hyperglide. If and when that comes out, try replacing your current gear
    cluster with the new design - Suntour usually makes new stuff
    compatible with old - and replace the chain at the same time.
    
    
    Rod

    Try to find out the source of the grinding first. Hold the rear
    wheel off the ground while spinning the crank and shifting the rear
    derailleur.
    At this point I'd guess that the chain is trying to run between
    two rear cogs and the occasional skipping is caused by the chain
    side plate meshing (momentarily) with the tooth, instead of the
    roller meshing with the tooth,as is normal.
    
    Since this is a nearly new bike with stock components, it's not
    likely to be a chain-line problem, or a chainwheel lateral spacing
    problem, but both those could cause your symptoms.
    
    I'd start by getting it to run quiet with the chain on the outer
    chainwheel and outer rear cog.
    Doing this will define the correct upper limit set screw position,
    correct cable tension, and rear derailleur lever position.
    Then shift down to the next lower gear and see what happens.
    Too much movement of the rear derailleur = too much initial cable
    tension. Too little movement = too little tension.
    Repeat for each gear position. Eventually you'll see where its going
    wrong.
    
    Terry

    
    You problem is a combination of many, many items. The Suntour
    XCT grouppo is a low end grouppo on the Suntour line. If you got the
    X press shifters with the grouppo, then that would even enhance 
    the shifting problem a little more. This is because the system is 
    little more sophistocated then the thumb or wishbone ratchet shifters.
    
    The secret to index shifting on the any system is based mostly on 
    cable tension. The components that make the indexing work are the
    shifter, rear derailluer, freewheel or cassette (spacing) and the 
    chain. Since there are so many variables, you are probably wondering 
    how much will it this going to cost me? It might not cost anything if 
    you are good with mechanical items.
    
    1) Try adjusting it: the 2 screws on the derailluer are for the 
       high and low gear stops. they have nothing to do with the indexing.
       They just stop the derailluer so than you chain will not go into
       you spokes and rear dropout. The trick to adjusting the indexing
       is in the barrel adjuster in the rear derailluer. All you have to do 
       is set you shifter to the 2nd or 3rd gear in the rear. The front 
       should be set on the middle chain ring to reduce chain angle. 
       After the shifter is set on the one gear that you picked, listen 
       to the noise (if any) in the rear of the freewheel and chain. Turn 
       the barrel adjuster in half turn increments to determine the most
       quiet area in that gear. Once that is adjusted, all the gears should
       be indexing properly. If it's not, bring it back to the shop because
       you will probably make worse then make it better. If you want to
       still tackle this on your own, buy the Bicycling Magazine
       Maintainace book at your local book store for $14.95 and it will
       give to step by step instructions.
    
    2) Switch the chain: This is you cheapest investment to get better
       shifting. Get a Sedis Sport chain for $6-10 and replace the factory
       one. Believe me, it does make a big difference.
    
    3) Get a thumb shifter if you has the X press stuff. This will tighten
       up the tolerance on the cable tension and improve you shifting.
    
    4) Look into get a new derailluer, shifter, and freewheel combo. I
       would tell you to go with Shimano stuff but you will pay extra 
       because you will have to get a cassette hub and re-build a rear
       wheel. Shmano does make a 7 speed freewheel but only in Dura Ace
       which is big bucks.
    
    My recommendation is to start off with item 1 and 2 and if that doesn't
    solve you problem. Then let us know and maybe I will even take a run
    down if you live close by.
    
    Good Luck,
    
    dave
       
    
    
     
    

    If you  follow  the  advice  in  .7,  make  sure that when you are
    adjusting the cable tension you are trying to put the chain on the
    correct  cog.  To check this, move the lever to the position which
    brings  the  deraileur  as close to the wheel as possible (ie. low
    gear),  now  move  the lever 2 clicks from that position. When you
    try  to  get the chain to stop rattling, it should be on the third
    cog (counting from the largest.)

    There's no reason to switch to Shimano. Suntour works fine, if you
    get  it  adjusted  right.  We  can start the usual arguments about
    which  is better, but the differences aren't big enough to warrant
    switching on the bike you describe.

--David

    Could someone put in a table that shows some of the different types
    of deraileurs and ranks them in terms of price/performance?
    thx
    

    Thanks for the advice.  I am going to attempt the full diagnosis this
    weekend.  I borrowed a bike stand from a friend and will have
    everything (?) I need to check the settings.
    
    Re: -.1  In the Spring, Bicycling Magazine publishes an issue dedicated
    to presenting specifications for all decent bikes.  In that issue, they
    published a listing of well-known component groups listed in order of
    dollar ranges of bikes you can expect to see them on.  I found this
    helpful when looking at a bike to see whether it is "over" equiped for
    the price; making it a good bargain 8^).
    
    I'll let you know next week how I made out on the adjustments.
    
    Thanks again,
    
    
    Jack Boyle

RE: .9

    It's very  difficult to find out anything about what seperates one
    model  of  derailleur  from the next. If you ask the manufacturer,
    you'll  get a lot of noise, but very little real info. Buy-cycling
    magazine  isn't  about  to  tell you that two models are identical
    except   for   price  because  they  have  to  be  nice  to  their
    advertisers.

    You can find out the relative prices, but not what the extra money
    gets you.

--David

    
    Sometimes different models have different features -- sometimes
    these are more dependent on how new the model is (old C-Record
    versus new Athena) rather than for price reasons.
    
    Example: The newer Campagnolo derailleurs use slant parallelogram
    design.  A feature difference: one Campy derailleur has a setting
    for wide-range vs. narrow-range clusters.  (This is either the
    Chorus or the Croce d'Aune, I recall.)
    
    Other than that, .-1 is right: it's very subjective, including
    how durable a derailleur is supposed to be.  Two statistics to attend
    to, however, are Largest Cog, and Range (difference between smallest
    and largest cog), when choosing a derailleur to suit your needs.
    
    -john (happy both with his Ultegras and his C-Record)

    What does the slant parallelogram design buy you?  I'm currently
    considering buying a C-Record for my ancient Peugeot, and I'm wondering
    what benifits there are to the newer designs.  BTW, I don't care about
    indexing.
    
    Barry 

    My understanding is that the slant parallelogram design keeps the
    derailleur better aligned (parallel) to the chain in more of the
    gear positions.  Suntour has had this design for years and years
    (even on the economy derailleurs), with good results... Campagnolo
    has adopted this (including with the new Record?) because the patent
    ran out, as I recall.
    
    -john

    I thought that the advantage of the slant parrallelogram
    is that the derailleur moves at an angle, so that the
    upper jockey wheel follows the slope of the freewheel better.

    -Jeff Bell

    Hi again,
    
    The noise in the derailleur (that originally started this note) was
    caused by dirty chain/components.  Although I tend to wipe things down,
    I never took the time to really scrub them (thinking that a new bike
    doesn't need such treatment?).  So I took out the engine degunk (bad
    for parts?), and cleaned the chain, derailleurs, etc and lubed the h*ll
    out of everything.  The chain was so clean (how clean was it!) tht a
    white towel run over the chain came away clean.  Big benefit, no more
    noise for now.  Took a while but I'm happy and silent again in Jersey.
    
    Thanks again,
    
    
    Jack Boyle