I've trying to figure out this one but couldn't... I have a 9 o'clock travelcard for all of Zurich. But I need to go to Schaffhausen.

As I understand it, I'd need to buy a ticket that covers the zone outside Zurich. But in the case of an IR train, the last stop before Schaffhausen is Bulach, so almost all of the way is inside Zurich. I'd get off the train at the first opportunity in Schaffhausen.

In that case, do I still need to buy a Bulach-Schaffhausen? Is there any cheaper way to do this?

ZVV ticket on long-distance trains (and this includes IR) are only valid to the last scheduled stop in the ZVV area.

So that means if you took the S-Bahn you could use your ZVV pass virtually all the way to Schaffhausen, only having to buy a ticket for the last short leg. If you take the IR, you will indeed have to buy a ticket from Bülach to Schaffhausen.

If you commute regularly, there are special combined deals available. For a single trip, the cheapest way is to take a slower train which stops just inside the ZH border. For example if you catch a train to Winterthur and then the S33 from there, you only need a ticket from Schloss Laufen am Rheinfall to Schaffhausen.

The downside is it takes twenty minutes longer - and the price difference is about 15CHF (round trip, with half-fare card) so it's really up to you if that's worth the time and hassle.

in the winter months, Schloss laufen stop is closed so you would need a ticket from dachsen to SH

Really? The SBB timetable still lists arrivals and departures from there, will even sell you a ticket with today's date on it. Bizarre.

OK, Dachsen it is then.

yes, i used to live in dachsen and the SL stop closes normally from nov to beg april...........

IIRC I read somewhere that this was changed with the new timetable since December 2011.