Newbie on a newbie bike

Discussion in 'Mountain Bikes' started by Paul Gravestock, May 5, 2003.

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  1. I've just taken a new bike out for its first ride in anger (i.e. the chain came off when I got
    carried away with my frantic shifting as I struggled up a slope....)

    Before the chain came off there was no noticeable problem with the derailers or gear cassette,
    however after the chain came off I am getting what feels like the chain slipping, or changes in gear
    (without any input from me). I've read some of the recent posts about chains slipping, or gears
    jumping, and the replies seem to imply worn parts - given my bike has about 20 miles on the clock, I
    hope I don't come into the worn parts category.

    The derailers on my bike are Shimano Deora, I think the cassette is a Shimano Mega Drive Train.

    Does anyone have any suggestions?

    Thanks

    Paul
     
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  2. Jamie

    Jamie Guest

    You may have bent the derailer or a ring on the rear cassette look to see .And you need to describe
    the bike a little better. If it a wallgoose type they don't take abuse very easily.

    --
    J/O Trailblazer At large !!
     
  3. Sorni

    Sorni Guest

    " Paul Gravestock" <[email protected]> wrote in message
    news:[email protected]...
    > I've just taken a new bike out for its first ride in anger (i.e. the chain came off when I got
    > carried away with my frantic shifting as I struggled
    up
    > a slope....)
    >
    > Before the chain came off there was no noticeable problem with the
    derailers
    > or gear cassette, however after the chain came off I am getting what feels like the chain
    > slipping, or changes in gear (without any input from me). I've read some of the recent posts about
    > chains slipping, or gears
    jumping,
    > and the replies seem to imply worn parts - given my bike has about 20
    miles
    > on the clock, I hope I don't come into the worn parts category.
    >
    > The derailers on my bike are Shimano Deora, I think the cassette is a Shimano Mega Drive Train.
    >
    > Does anyone have any suggestions?

    If you got "chain suck" (front or rear) when it came off, then you may have bent a link whilst
    unjamming it. Check by back-pedaling slowly and watching to see if the derailleur jumps a bit when a
    certain section of chain passes thru.

    If the chain merely fell off loosely, then your shifting problems are probably unrelated. If you
    bought the bike at an LBS, take it back and have 'em check it over.

    Bill "not really a 'whilst' kinda guy" S.

    --
    They say Einstein conceived the Theory of Relativity while riding a bike.

    Me? I decided what to have for lunch.
     
  4. Westie

    Westie Guest

    " Paul Gravestock" <[email protected]> wrote in message
    news:[email protected]...
    > I've just taken a new bike out for its first ride in anger (i.e. the chain came off when I got
    > carried away with my frantic shifting as I struggled
    up
    > a slope....)
    >
    > Before the chain came off there was no noticeable problem with the
    derailers
    > or gear cassette, however after the chain came off I am getting what feels like the chain
    > slipping, or changes in gear (without any input from me). I've read some of the recent posts about
    > chains slipping, or gears
    jumping,
    > and the replies seem to imply worn parts - given my bike has about 20
    miles
    > on the clock, I hope I don't come into the worn parts category.
    >
    > The derailers on my bike are Shimano Deora, I think the cassette is a Shimano Mega Drive Train.
    >
    > Does anyone have any suggestions?
    >
    > Thanks
    >
    > Paul
    >
    >

    I reckon that things are just bedding in and more than likely you've got some new cables stretching
    there somewhere. That'll make a small change to the position of the derailleur and cause it to shift
    by itself or slip because it's kinda in between gears. Try tweaking the adjuster knob that's on the
    shifter on the handlebars. Turn it slow and test ride bike. No more than a couple of turns should
    make a difference. If in doubt, take it back to the LBS. They should help you with this free of
    charge - the first few times anyway.
    --
    Westie
     
  5. David Kunz

    David Kunz Guest

    Paul Gravestock wrote:
    > I've just taken a new bike out for its first ride in anger (i.e. the chain came off when I got
    > carried away with my frantic shifting as I struggled up a slope....)
    >
    > Before the chain came off there was no noticeable problem with the derailers or gear cassette,
    > however after the chain came off I am getting what feels like the chain slipping, or changes in
    > gear (without any input from me). I've read some of the recent posts about chains slipping, or
    > gears jumping, and the replies seem to imply worn parts - given my bike has about 20 miles on the
    > clock, I hope I don't come into the worn parts category.
    >
    > The derailers on my bike are Shimano Deora, I think the cassette is a Shimano Mega Drive Train.
    >
    > Does anyone have any suggestions?
    >
    > Thanks
    >
    > Paul
    >

    I agree with both posters. It's possible that you bent a ring or tweaked the chain. But if the drive
    train is Diore, that's pretty unlikely (unless you're somewhat of an animal :)).

    It's more likely that the cable stretched slightly. The 9 speed setup made a novice engineering
    mistake -- IMO, the engineers should be shot! A very small cable movement shifts a gear. This means
    that even slight stretch needs to be compensated for (and and friction or even heavy oil in the
    cable or housing will cause shifting problems). In fact, even temperature changes can mean that you
    need to make a slight adjustment because of the cable runs along the frame that are outside the
    housing! This is done by turning the barrel at the shifter (or at the rear deraileur).

    I make adjustments in 1/4 turn increments and test. Try turning the bike over and pedaling. Shift
    into the gear that's giving you the most problem. It'll probably jump a little. Look to see which
    way it's jumping. If it's trying to climb to a bigger gear, loosen the adjusting barrel in 1/4 turn
    increments until it doesn't. If it's trying to drop to a smaller gear, tighten in 1/4 turn
    increments until it doesn't. Once you've gotten it so that it's not jumping, shift up and down to
    make sure that it's ok in the rest of the gears (shift the front DR and test again). If it's not,
    try Sheldon Brown's web site for some good adjusting info: http://sheldonbrown.com

    David
     
  6. " Paul Gravestock" <[email protected]o.uk> wrote in message
    news:[email protected]...
    > I've just taken a new bike out for its first ride in anger (i.e. the chain came off when I got
    > carried away with my frantic shifting as I struggled
    up
    > a slope....)
    >
    > Before the chain came off there was no noticeable problem with the
    derailers
    > or gear cassette, however after the chain came off I am getting what feels like the chain
    > slipping, or changes in gear (without any input from me). I've read some of the recent posts about
    > chains slipping, or gears
    jumping,
    > and the replies seem to imply worn parts - given my bike has about 20
    miles
    > on the clock, I hope I don't come into the worn parts category.
    >
    > The derailers on my bike are Shimano Deora, I think the cassette is a Shimano Mega Drive Train.
    >
    > Does anyone have any suggestions?
    >
    > Thanks
    >
    > Paul
    >
    >

    Guys,

    Thanks for your useful (and practical!) suggestions - I guess I will have something to occupy
    my weekend!

    Regards

    Paul
     
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