Dear Lascauxcaveman,

So I'll order the exact replacement 50T and 40T rings then, and I'm happy to presume that there will be a bit of play in the rings fitting, or that my measurements are out.

Also thanks for responding with a username that I take to be a sign! My family are on the cusp point of booking a gite in the Dordognefor the end of July, more specifically in Montignac: your user name is therefore quite the coincidence! So I'll book the gite as well. It is likely to be a bit more expensive than the chain rings. I'll give your regards to the buffalo when I see them, or at least the exact replica of the caves that has recently opened to the public.

Dornfield