Hi Badger,

Many thanks for your replies. All very useful.

Thanks,
Jack.



"Badger_South" wrote in message
...
On 5 Jul 2004 21:55:08 GMT, Werehatrack
wrote:

On Mon, 5 Jul 2004 11:03:27 CST, "Daniel Kelly \(AKA Jack\)"
wrote:

I fear my bike has a fracture in its front cog. I first noticed
something
was wrong when I heard the front cog hitting against the front
derailleur
once every revolution of the pedals. It turned out the front cog was
actually bent and so "wobbled" as it rotated, relative to the front
derailleur. Closer inspection showed that the front cog was a little
loose
and could be jiggled a little. The join between the front cog and the
right
pedal was clearly loose.

I took the right pedal off and found a little crack in the front cog.
Some
photos are he
[snipped]

Is this a fracture?

Yes. It looks like you've got a typical non-repairable crank set
there. The large and small sprockets (also called chainrings) are
both riveted to the middle-size one, and the middle sprocket has the
splines broached into the center to mate with the hub. Unfortunately,
these almost never can be disassembled nondestructively, and no
replacement parts for the individual pieces are sold in any event.

Great answer! Had all the specifics that other replies (including my dumb
comments about metal fatigue, heh) lacked. Very informative.

-Badger