Why is the curve modifier deforming strangely? I modelled a part of a bicycle chain added an Array and a Curve Modifier 

everything worked nicely until I added cogs and translated and scaled the chain parts to fit the cogs.

I tried to apply transformations, re-added the Curve Modifier but had no success, it still deforms the chain that strange:



Before I messed it up it looked like this:



How could it be fixed?

.blend
If you want the chain to follow the curve, move it to the origin of the curve (they need a common center).

Select the curve, press Shift-S and select Cursor to Selected
select the chain, press Shift-S and select Selection to Cursor

Then apply your curve modifier and the chain will follow the curve correctly.

The deformation is fixed scaling the object