OK here are some images

[Linked Image from lh5.ggpht.com]

and the bolt I am talking about is not the tensioning screws, it is the bolt that holds the bar in place once it has been nipped up by the tensioning screws.

[Linked Image from lh4.ggpht.com]

[Linked Image from lh3.ggpht.com]

[Linked Image from lh3.ggpht.com]

And just to show off the other parts

[Linked Image from lh5.ggpht.com]

I suspect this part was added later

[Linked Image from lh5.ggpht.com]

as the original off switch is gone walkabout.

[Linked Image from lh6.ggpht.com]


So the issue here is the bolt that holds the bar in place. I suspect i could replace it with another bolt and be OK - the thread where the nut screws on is stripped bare.

So the bar won't stay tight, and the chain falls off..