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Chainring Advice

jerryfuddjerryfudd Posts: 343
edited June 2013 in MTB workshop & tech
Hi,

My commuter has been jumping under load so I'm replacing the rear cassette and chain - can someone advise me on the wear of the chainrings and if they need replacing also or how much life is left in them.

D8AF3F46-B11C-4717-BDE6-8F8A02957227-1112-00000077079CDEF1_zps4cfca707.jpg?t=1372225526

C47852E1-C772-4AF7-AF6B-AEDB1CB7387B-1112-00000076FF1838A0_zps439bfd44.jpg?t=1372225518

Some of the teeth look flattened off but I saw somewhere but sometimes it can be on purpose to aid shifting?

thanks,

Dan

Posts

  • nicklousenicklouse Posts: 81,520 Lives Here
    looks OK to me.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • concordeconcorde Posts: 1,111
    Granny ring is starting to shark tooth but don't think it'll cause too much worry. Other rings are fine.
  • jerryfuddjerryfudd Posts: 343
    concorde wrote:
    Granny ring is starting to shark tooth but don't think it'll cause too much worry. Other rings are fine.

    thanks, shows what i know i was looking at replacing the middle and outer :mrgreen:

    ....are the flat teeth meant to look like that then?

    Dan
  • nicklousenicklouse Posts: 81,520 Lives Here
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • No SweatNo Sweat Posts: 103
    Hard to tell just by looking at the chainrings...

    The only real test will be when you have the new chain. When you have assembled it all, if the chain rings are not too worn, the new chain will fit snugly around the chainrings. If you can see a gap between the chain and the chainring (i.e. in 'valleys' between the 'teeth' - sorry for mixing metaphors there) and the chain feels 'slack' if you try to move it around on the chain ring, then the old rings are probably too worn and will prematurely wear the new chain and therefore the new cassette as well.
  • Chunkers1980Chunkers1980 Posts: 8,035
    The granny looks fine. They are deeper than the rest as it only needs to shift up.

    From the front on picture just around 12 o'clock above the mega nine sticker the flat part there and ones similar are meant to be like that as it is a shifting aid.
  • OuijaOuija Posts: 1,386
    concorde wrote:
    Granny ring is starting to shark tooth but don't think it'll cause too much worry. Other rings are fine.

    Actually, the granny ring on SLX comes with that shark tooth design when new (unlike a lot of granny rings) which can be a bit misleading. In fact, all three rings start out with a slight shark tooth design to them on SLX, especially the composite middle ring. Though non of that applies to the touring version of the SLX with the larger 26/36/48 combination.
  • jerryfuddjerryfudd Posts: 343
    To me the middle ring looks a bit too worn for my liking, other 2 look fine.

    thanks all, what are you checking for Beginner?

    Dan
  • OuijaOuija Posts: 1,386
    For Comparison.....

    SLX 22
    83371.jpg
    SLX 32
    38187.jpg
    SLX 44
    38186.jpg

    note the slight shark toothing as standard. Can mislead you into thinking they are more worn than they are (on more traditional rings i'd be thinking of replacing them if they looked like that too)
  • The RookieThe Rookie Posts: 27,747
    jerryfudd wrote:
    To me the middle ring looks a bit too worn for my liking, other 2 look fine.

    thanks all, what are you checking for Beginner?

    Dan
    Just looking at the shape of the valleys between the teeth, I'm not saying it is (or isn't) worn, just looks like it may be!
    Unless it's really bad you won't tell from a photo for sure.
  • jerryfuddjerryfudd Posts: 343
    thanks all, I think im going to stick the new sprocket and chain on and see how the fit looks.

    thanks again,

    Dan
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