Chainring dowel pins

After many years of neglecticly neglecting them B)... I decided that I am going to find out, one way or the other, what they are and what they're intended for. As a Dutchmen in virtual England, maybe not the right word (pls correct me if I'm wrong). Chainring dowel pins?

I wonder if anybody knows the answer here? Please see pictures.





Comments

  • By the way; They're made of steel. So probably they serve as a guide to distribute the chain to the other chainring, serving as a fender for the softer aluminium. But who knows for sure. Maybe I am wrong...
  • First.Aspect
    First.Aspect Posts: 14,855
    They are there as a shifting aid. They are right next to chain link shaped indents. It isn't a mystery.
  • gethinceri
    gethinceri Posts: 1,535
    oxoman said:

    They also help the chain back on if it drops off and hopefully stops it getting stuck between chainrings.

    No, that’s a different thing. Look at the pics.
  • banditvic
    banditvic Posts: 549
    They are there to lift the chain onto the top of the next ring.
  • Chainring dowel pins purpose

  • moonshine
    moonshine Posts: 1,021
    ^ this photo suggests they assist with the Downshift from outer to inner) Chainring (given the rotation direction of the chainset)
  • Um, no?
  • They are there to stop the chain getting jammed between the ring and the crank if the chain comes off. Hence the position of them in relation to the crank, unless the rings aren’t installed correctly.
  • gethinceri
    gethinceri Posts: 1,535
    edited September 2020

    They are there to stop the chain getting jammed between the ring and the crank if the chain comes off. Hence the position of them in relation to the crank, unless the rings aren’t installed correctly.

    No, look at the pictures, he's not referring to the pin you refer to.
    NOT
  • lesfirth
    lesfirth Posts: 1,382
    edited September 2020
    moonshine said:

    ^ this photo suggests they assist with the Downshift from outer to inner) Chainring (given the rotation direction of the chainset)

    Oh no it doesn't! errr maybe it does.
  • Chainring dowel pins purpose

    Wow!! That makes sense. That must be the right answer to my question. Respect! How do you know that Charlie Croker?! Is this written somewhere? I am in possession of the Dura Ace prospectus of the 7800 group (2004). Back in the days, that was a magazine about the new group. There is nothing in there about these chainring dowel pins. I never knew this and suspected they were uses during routing procedures to secure the chainring.

    Btw: Yes there is confusion in this thread. The mentioned six dowel pins on a single chainring differ from the single pin located under the right cranck which serves to prevent the chain from getting stuck in between the cranck and the chainring if it falls of.
  • gethinceri
    gethinceri Posts: 1,535
    Only confusion is with idiots who didn't read the OP or look at the photos.
  • They are there to stop the chain getting jammed between the ring and the crank if the chain comes off. Hence the position of them in relation to the crank, unless the rings aren’t installed correctly.

    No, look at the pictures, he's not referring to the pin you refer to.
    NOT
    Yeah I realised that when I looked at the pictures.
  • No problem. I should have thought of the confusion with the cranck pin before when I started the thread. It is not completely clear. Probably not all groups have these "chainring dowel pins". Still nobody is offended by my choice of words... Does this mean that these things are named correctly here in English?
  • gethinceri
    gethinceri Posts: 1,535
    No, we all know what you meant, apart from idiots who were incapable of reading words or look at pictures.