I've just refurbished my 750 Sport gear selector with Nigel's large and small gear selector bushes. I raise this here only because it is the same selector "architecture" as some singles. What a difference to a positive gear change on my Sport! The OD was perfect with a hot/cold pressing and the ID after pressing only needed a very minor amount of internal reaming - which is exactly what you want. Highly recommended bit of maintenance for your gear change assembly.

Kev