Chain ring sizing. Where did I go wrong?

mickus
mickus Posts: 199
edited August 2012 in MTB general
So I made a bit of an error buying chain rings.

I didn't realise that a shimano 36t middle ring wouldn't fit on my race face deus cranks. The internal spacing on the XT chainring is smaller than the race face cranks allow.

So my question is what is the measurement that I need to be looking out for when buying new rings for my race face cranks? Does anyone have recommendations on a 36t ring for a double and bash set up on these cranks?

Cheers,

Mike

Comments

  • nicklouse
    nicklouse Posts: 50,675
    So will a file sort it? The BCD will be the same but the shoulder diameter can and is often different between brands.

    Either use a file or buy mod original ones.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
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  • mickus
    mickus Posts: 199
    I guess a file would sort it, but I don't fancy trying. A lot of effort for me to likely just screw it up...

    Looks like I'll just have to buy a race face ring!

    Are there any other companies that make rings that fit the race face cranks?

    Cheers
  • nicklouse
    nicklouse Posts: 50,675
    mickus wrote:

    Are there any other companies that make rings that fit the race face cranks?

    Cheers
    most if you use a file.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • mickus
    mickus Posts: 199
    nicklouse wrote:
    most if you use a file.

    I really don't want to file bits down. I can deal with the fact if race face rings will be the only ones to specifically fit the cranks...
  • njee20
    njee20 Posts: 9,613
    You're removing non essential material from the ring, MTFU and just do it!
  • Twelly
    Twelly Posts: 1,437
    njee20 wrote:
    You're removing non essential material from the ring, MTFU and just do it!

    +1
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  • YeehaaMcgee
    YeehaaMcgee Posts: 5,740
    TwellySmat wrote:
    njee20 wrote:
    You're removing non essential material from the ring, MTFU and just do it!

    +1
    +Potato
    My photos
  • MacAndCheese
    MacAndCheese Posts: 1,944
    Currently running a Hope ring on my raceface Atlas AM cranks, fitted with no problems.
    (running 1 x 9 and 1 x 10)
    Santa Cruz Chameleon
    Orange Alpine 160
  • cooldad
    cooldad Posts: 32,599
    A real man would just pick it away with his nails.
    I don't do smileys.

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  • mickus
    mickus Posts: 199
    njee20 wrote:
    You're removing non essential material from the ring, MTFU and just do it!

    helpful...

    When I was a kid I would have happily spent half my weekend bodging bits to my bike to get it on the trail as fast as possible and as cheaply as possible. Now that I have money and a certain degree of patience I'm happy to hold fire and not have to file things down just to make them fit...

    I've read a bit more on the subject and see that plenty of people have happily filed away at their chain rings to get them to fit - fine by me but it still didn't answer any of the questions I actually asked in this thread.

    All I wanted to know was what dimensions did I miss to get a part that didn't fit and what brands fitted as standard. If I had asked how to get a square block to fit in a round hole then filing obviously would have been the answer.

    If the new ring I ordered last night doesn't turn up before this weekend's ride then maybe my patience will be tested and the file will come out. But the extra £2 for next day delivery is cheaper than buying a new file...
  • nicklouse
    nicklouse Posts: 50,675
    ok to go into more detail the inner and outer shoulders of the spider vary model to model make to make and year to year.

    normally the inner is a bit smaller than the outer. or is it the otherway around, i forget, some makers use the same size but not always the same size on each model or year.

    sram and shimano tend to do things directly the whole time.

    what you are looking for is something that once you have measured it you will have to ask the sellers what theirs measure as it is not something that the ring providers state.

    some will state inner/middle/outer for the ring position on "a" standard crank. now this may be the same as yours but may not be.

    So buy ones that are stated to fit your cranks of get the file out.

    Lost count of the ones i have filed. thankfully we had access to a lathe at the shop so the steel rings took less time than by hand.

    And no i have no idea waht the measurements were as there was no point realy as you never knew what you would get.

    cant remember the year that shimano changed the soulder widths around for that year but it was a pain.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • Anonymous
    Anonymous Posts: 79,667
    Similar issue I had going single ring on the hard tail build. 3x cranks off the old GT and perfectly fine so continued with the bash I'd already had on it and wanted a single ring in the middle. Turned out it just didn't quite fit. Possibly because of difference in brand or because of trying to fit a single to the middle of a triple.

    *Anyway*... file sorted it ;)

    (though I filed the shoulders of the spider).

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