Thanks, I've been looking on Ebay as well, luckily there seems to be enough variety in diameter :)
I'm also thinking of using a bit of inner tube to put some extra protection on the corners underneath before finishing it off with the heat shrink tube, which would increase the diameter some more - I'm sure I'll find something that suits. Thanks again for the suggestion, it hadn't occurred to me at all.
If you go down the heat shrink route, use adhesive-lined so that the ends are sealed, otherwise you run the risk of creating a water trap and your hanger will be rusty when you peel the cover off to revert to gears
Thanks, I've been looking on Ebay as well, luckily there seems to be enough variety in diameter :)
I'm also thinking of using a bit of inner tube to put some extra protection on the corners underneath before finishing it off with the heat shrink tube, which would increase the diameter some more - I'm sure I'll find something that suits. Thanks again for the suggestion, it hadn't occurred to me at all.