Originally Posted by
roshea
Can you please provide some info about this bolt? What is it likely to be called and where would I get one?
It's called a sacrificial bolt.

Try here,
http://www.bikepro.com/products/rear...der_bolts.html, or here
http://www.pilo.co.il/Default.aspx
You may just have to go to local nuts & bolts store. Can't find my original link.
Also called "break-off bolt".