Polypipe waste sizes

Another problem with the shower I am trying to fit..

The old waste and P trap is 1 ¾?. The new waste I bought is 1? shorter than the old so I need a new P trap but it looks as if 1 ¾? is no longer a standard ? its all 40mm or 32mm (1 ½? or 1 ¼? in old money). The only 1 ¾? wastes I can find are this length ? I should have known?..

Is it right that you can?t get 1 ¾? polypipe connectors any longer? I can buy another waste but is it possible to get an adaptor to the 1 ¾? waste pipe that is there already?

I don't know the answers to your questions specifically and I don't know whether you are referring to Polypipe as a specific manufacturer (which it is) or to polypipe as a generic term for such pipe and fittings, but I do know that different manufacturer's pipes and fittings, while nominally the same, may not fit one another.

Rob Graham