Going to be getting the bikes off the floor this week.

Plan was to use these at 90 degrees, with the bike hanging vertically:
http://www.ikea.com/gb/en/catalog/products/10051305/

Now here’s the catch: the walls are plasterboard. Assuming worst case scenario, would it support a bike using correct fixings (something like http://www.qvsdirect.com/plaster-board-fixings?gclid=CJ-Y3NurorgCFXMRtAodqT4AmQ or http://www.toolstation.com/shop/Screws+Fixings/Cavity+Fixings/d90/sd1930)?

Or to put it another way – will I die horribly if I do mount single bikes straight onto a plasterboard wall?

Look for where the studs are and fix into them.
Alternatively – you could always reinforce the wall with ply.

That would be a great deal of weight on a small area. Could you fasten a wood board on to dissipate the weight? something say 1ftx1ft or bigger.
Edit: Yesh, what he said /\

That’s my thinking too. I just wanted to check that if studs proved difficult to locate / awkward to get to / I’m too lazy to find them, that the house wouldn’t collapse.

Not too keen on the idea of removing a wall to put in batons, but I suppose needs must…

You could always fix tothe brick wall behind the plaster board with longer fixings.