Derailer trying to lunch the chain

Sesquepidilian
Sesquepidilian Posts: 83
edited August 2012 in Your road bikes
My cheapo Airlite 100 has started an annoying habit of trying to wrap the chain around the rear wheel axle. If I'm hurrying down the cassette on an incline (yeah I know, way to mistreat the bike etc) it's twice now spat the chain off of the cassette and the chain has jimmy-jammed between the cassette and the axle, usually needing to be praized past a spoke or two to get refitted.

Is this a sign of a fooked derailer, or just immensely out of adjustment ? It's a cheap slut of a cycle, about 6 months old and has been ridden hard and fast almost daily and is showing every mile it's done.

Comments

  • ALaPlage
    ALaPlage Posts: 732
    Are you changing gear under load on an incline? You need to back off ever so slightly to change gear or risk what you find is happening where the chain jumps off the rear sprocket. Worse you can cause the chain to snap.

    Just take the tension or load off as you change. With practise it doesn't have to effect your pedalling rythmn.

    Di2 system automatically takes the load off as you change and is one of the claimed advantages of the electronic groupsets.
    Trek Madone 5.9
    Kinesis Crosslight T4
  • antfly
    antfly Posts: 3,276
    So just get a Di2 groupset, or first you could try tightening the lower limit screw on the mech.
    Smarter than the average bear.
  • alihisgreat
    alihisgreat Posts: 3,872
    Its just not set up properly.. chances are your LBS could sort it in 5 mins. or you could google how to adjust your model of derailer.
  • ALaPlage
    ALaPlage Posts: 732
    antfly wrote:
    So just get a Di2 groupset, or first you could try tightening the lower limit screw on the mech.

    Worth a go as it may be the cause but if this was the problem you would likely experience the chain moving off the rear big sprocket and into the spokes on the flat too. If you try cycling on a flat road and keep changing all the way up and it doesn't pop the chain off I think it's more likely because you are changing gear under load on an incline as you described. If it is the limit screw you may only have noticed this when on an incline as it is rare on a flat bit of road you would change quickly through the gears to a lower gear.

    I also wasn't suggesting the OP gets an electronic groupset but pointing out it is a problem of mechanical setups which the Di2 claim to resolve.
    Trek Madone 5.9
    Kinesis Crosslight T4

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