unknown plastic spacer on triple crankset

itboffin
itboffin Posts: 20,072
edited July 2011 in Workshop
As the title says I have an unknown 7mm black plastic spaced on the axle of my new shimano 5603 triple crankset. The normal spacer for the left crank is there as well, however I can see no use or function for this one, does anyone know what its for?
Rule #5 // Harden The Feck Up.
Rule #9 // If you are out riding in bad weather, it means you are a badass. Period.
Rule #12 // The correct number of bikes to own is n+1.
Rule #42 // A bike race shall never be preceded with a swim and/or followed by a run.

Comments

  • Wooliferkins
    Wooliferkins Posts: 2,060
    Item 11? http://techdocs.shimano.com/media/techd ... 646645.pdf
    Neil
    Help I'm Being Oppressed
  • keef66
    keef66 Posts: 13,123
    I have a 105 triple. There's a plastic spacer on each side.

    Non drive side it's kind of wide with a bevelled edge (6). Drive side its thicker but smaller diameter (11); didn't even notice it first time I took it apart cos ot was just stuck on the axle hidden behind the chainrings.

    I'm assuming they are to provide the proper chainline. Mine works OK
  • itboffin
    itboffin Posts: 20,072
    Wooliferkins wrote:
    Item 11? http://techdocs.shimano.com/media/techd ... 646645.pdf

    Yes

    Surely if I use that the left crankarm is not going to fit.
    Rule #5 // Harden The Feck Up.
    Rule #9 // If you are out riding in bad weather, it means you are a badass. Period.
    Rule #12 // The correct number of bikes to own is n+1.
    Rule #42 // A bike race shall never be preceded with a swim and/or followed by a run.
  • keef66
    keef66 Posts: 13,123
    It's a triple crankset. It's designed to work with 2 spacers. Presumably the axle is longer than on a double??

    As I say, mine has both spacers fitted and the left crank arm fits just perfectly.

    If you leave it out you'll have the opposite problem: you won't be able to preload the bearings with the crank cap and the whole thing will be slopping about from side to side.
  • Wooliferkins
    Wooliferkins Posts: 2,060
    A triple sits further out as you basically add another inboard ring. On a double your chain line runs through a point between the two rings, on a triple you need to move that outboard a bit as the middle ring becomes the point your chain line runs through.
    Neil
    Help I'm Being Oppressed
  • Paul E
    Paul E Posts: 2,052
    On mine I only have the bevelled one on the non drive side, I have only ever had it off three times and I am extremely carefull when taking things apart, I have no slop or play and the gear changes are spot on and have been for nearly two years.

    It's getting a service including a new ultegra bb next thursday, will ask the mechanic then
  • keef66
    keef66 Posts: 13,123
    I didn't think I had the drive-side one cos it sits so snugly on the axle hidden behind the chainrings.
  • Paul E
    Paul E Posts: 2,052
    keef66 wrote:
    I didn't think I had the drive-side one cos it sits so snugly on the axle hidden behind the chainrings.

    I didn't notice anywear or noise or anything on the drive side bb cup either and I think with the amount of miles I have put through it a problem with a missing washer/spacer would have shown up by now
  • itboffin
    itboffin Posts: 20,072
    I hada closer look last night, all makes sense now.

    Thanks all
    Rule #5 // Harden The Feck Up.
    Rule #9 // If you are out riding in bad weather, it means you are a badass. Period.
    Rule #12 // The correct number of bikes to own is n+1.
    Rule #42 // A bike race shall never be preceded with a swim and/or followed by a run.
  • itboffin
    itboffin Posts: 20,072
    Triple front mech arrived today, should be just about set for Sunday.

    If I like it my compact 5650 will be in the classifieds if anyone's interested.
    Rule #5 // Harden The Feck Up.
    Rule #9 // If you are out riding in bad weather, it means you are a badass. Period.
    Rule #12 // The correct number of bikes to own is n+1.
    Rule #42 // A bike race shall never be preceded with a swim and/or followed by a run.
  • Paul E
    Paul E Posts: 2,052
    itboffin wrote:
    Triple front mech arrived today, should be just about set for Sunday.

    If I like it my compact 5650 will be in the classifieds if anyone's interested.

    I might be, on a 105 triple but I simply don't use the 1st chain ring.

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