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Rear cassette replaced

Discussion in 'Bicycle Mechanics and Repairs' started by Batch, 26 Nov 2007.

  1. Batch

    Batch New Member

    Hey,

    I took my two month old hybrid into the LBS for a brakes and gears tune up the other day. When they called me with the quote they recommended that I replace the chain and rear cassette as I'd worn through the teeth on the cassette.

    I've been commuting for years (currently clocking 100 miles a week) but I've never struck this before. The mechanic in the shop advised me to replace the chain once a month(!) to counteract this happening. I'm all for maintenance but this seems to be taking it just one step too far.

    Admittedly, after the chain and cassette was replaced the bike rides like a dream.

    Has anyone else struck a rear cassette that seems to wear out too quickly and how often are chains being replaced?
     
  2. Mister Paul

    Mister Paul Honky

    Location:
    North Somerset
    You can see how worn your rear cassette is by the shape of the gaps between the teeth. When new they're symetrical. The wear eats into the front of the gap. The chain and cassette wear together, so replacing just the cassette isn't a good idea, as the chain won't fit it properly.

    How often they wear out depends on how much you ride and in what conditions. If the chain gets mucky it'll wear more quickly.
     
  3. Two months is shocking! What is your lubing regime? OE cassettes and chains are often unplated which makes them much less durable but thats ridiculous.
     
  4. barq

    barq Senior Member

    Location:
    Birmingham, UK
    I won't reiterate the good advice above, but I think what your LBS is doing is a tad extreme! This is slightly oversimplifying but, there are two opposed views of chain replacement: 1) run until worn out and then replace cassette and possibly chainrings too, or 2) change chains before they significantly elongate with wear, thus meaning cassettes can be reused. Sounds like your LBS is going for a very extreme version of option 2.

    The question is whether that replacement was necessary. I guess you don't have the old chain to measure the elongation with a ruler, but I wonder if the improvement in shift was the new chain and cassette or just that the gears were re-adjusted.
     
  5. gbb

    gbb Legendary Member

    Location:
    Peterborough
    Unless its a hybrid of the very very cheapest order, its hard to find a valid reason for replacement.
    My wifes commuter is a £120 cheapie, with cheapie components. Its 6 years old and still running on original chain and components..it doesnt even get regular oiling. :sad:

    That said, a guy at work brought a cheap MTB....the cassette SNAPPED in the first week. Unfortunately, you gets what you pays for. Was it a particually cheap bike Batch ?
     
  6. PatrickPending

    PatrickPending Veteran

    Location:
    Leicester
    Mmmm replacing a chain every month is a bit extreme, and as for a chain/cassette lasting 2 months, well maybe on a supermarket bike but I'd be a bit miffed. On my old route my chain got as muddy as anything and lasted 3 months - now my commute is all road my chain is still good 3 months later (bought a park chain wear checking tool) - I do approx 230miles /week commuting so it does get a bit of use.

    I'd be suspicious if a shop told me what they told you!
     
  7. giant man

    giant man New Member

    Location:
    Essex innit?
    Changing the chain once a month is nonsense! Talk about sales boosting!

    A chain and a cassette should indeed be changed together, but doing this every 6 months for instance if you're doing high mileage seems adequate to me.

    Be sure to lube regularly with decent chain lube and check chain for stretching etc.
     
  8. Elmer Fudd

    Elmer Fudd Miserable Old Bar Steward

    Shouldn't a warranty have covered the parts or was it bought from a.n.other ?
     
  9. OP
    OP
    Batch

    Batch New Member

    Guys, thanks for the feedback. To answer at least some of the queries;

    1 It's a Cannondale Bad Boy 07 (650 model and approx £550)
    2 The work was completed at a different branch of the same store where bike was purchased (I've dealt with them on other matters and they seem v. professional)
    3 I try to lube (wax based) about once a week to once a fortnight, depending on conditions.

    I think I'll pick up a chain wear checking tool.

    Thanks for the advice
     
  10. I cannot agree with this statement sir.
     
  11. barq

    barq Senior Member

    Location:
    Birmingham, UK
    Park does a couple of nice tools for this, although you can get away with measuring with a steel ruler. Each pair of links (inner and outer) are an inch long when new, you can spot the elongation over a 12 link section.
     
  12. giant man

    giant man New Member

    Location:
    Essex innit?
    Please state your argument sir.
     

  13. My view is that a chain should be replaced before it exhibits signs of excess wear. Only a worn chain will damage cassette sprockets, therefore by replacing chains regularly a set of sprockets and chain-rings will last indefinitely.

    Exhibit (a) My mountainbike chain-rings, 40t and 30t GoldTech Ti, purchased in 1996ish. Still on my bike and still going strong.
    Exhibit (:biggrin: Mrs Mickles 1996 8spd XTR cassette. 22,000 miles and still going strong.
     
  14. Gerry Attrick

    Gerry Attrick Lincolnshire Mountain Rescue Consultant

    Is "wax-based" lubricant a clue to the problem? If the bike is being used in all conditions, I would suggest wax-based lube is not appropriate. I clapped out a chain on my old hybrid in record time using that stuff. Never had a problem using Finish Line wet lube.
     
  15. giant man

    giant man New Member

    Location:
    Essex innit?
    Fair enough mickle, good point. Guess that only comes with experience.