Hi, newbie needing help

[gypsylass]

Hi all, Many thanks in advance by the way lol

Right, i'm newly single after going through divorce and trying to stand on my own two feet and re-build my own bike by myself, which i have never been allowed to do before now.

Until now i've been doing ok, but have now come a little stuck, My chain ring is bent and when i change gears the chain jumps off my chain ring. Ok I realise that I need to replace my chain ring, but this is where i'm scratching my head. How do I know how to get the right size, is it diameter, or counting the cogs (?) round the outside.

[RBurrelli]

Sometimes difficult to change one crank in a crankset. It depends upon what you have. Number of teeth is how they are sized and then you have to match the bolt circle diameter to the crankset.
Google crankset BCD and check Wiki or Sheldon Browns website for information.

[nfmisso]

Hi Gypsylass;

Here are some links:
http://www.sheldonbrown.com/cribsheet-bcd.html
http://sheldonbrown.com/straighten-chw.html

If you share a picture of your bike and chainrings, we can provide much better advice. It may be cheaper to replace than repair, depending on what you have.

A picture like this:
http://s211.photobucket.com/albums/bb8/dianemisso/blue10072011/?action=view&current=IMG_0716.jpg
and this:
http://s211.photobucket.com/albums/bb8/dianemisso/Nigels%20Wheels%20042311%20A/Nigels%20Wheels%20042311%20B/?action=view&current=IMG_0450.jpg

Should provide almost all the information needed. And do count the number of teeth on each chainring.

If you are close to one of us, feel free to PM us for help.

[gypsylass]

(07-10-2011, 02:04 PM)RBurrelli Wrote:  Sometimes difficult to change one crank in a crankset. It depends upon what you have. Number of teeth is how they are sized and then you have to match the bolt circle diameter to the crankset.
Google crankset BCD and check Wiki or Sheldon Browns website for information.

Wow thanks for that, had a look although most of it is going right over my head right now lol, however i'll keep looking at it and maybe it'll sink in one day.

---

Quote:If you share a picture of your bike and chainrings, we can provide much better advice. It may be cheaper to replace than repair, depending on what you have.

Again thanks, I'll get some pics sorted as soon as.

[gypsylass]

Oooh by sheer chance i managed to figure that all out, 46T chain ring, single sprocket, 3/32" chain....oooh i sound like i know what i'm talking about now. not! Getting one off ebay, so hopefully that sorted.

Gonna add a photo, been advised to replace bottom bracket too, no idea where to start with that one, so, remembering what you said, this is what i'm looking at while i'm scratching my head.

ok hang on, gotta shrink pic as it's too big....