A friend has asked me to fix the gears on her Toys R Us bike. Something like this:

Yes I know!

Unfortunately the rear (twist) shifter is broken so I need a replacement. I was thinking of using one of these SRAM 3.0 as its only £4 and comes with a new cable. But I don't know if I need 2:1 or 1:1 actuation?

Does anyone have any experience with the really cheep (Falcon) shifters? I'm trying to keep thinks as cheep as possible otherwise I'll spend more then the bike cost.

why do they always put the forks on backwards?

1:1 is specific to SRAM isn't it?

That shifter will be a 1:1 ratio, the toysrus bike will more that likely be 2:1

Falcons don't go "cheep". You must be thinking of budgies.

2:1, although in my experience it's never exactly 2:1 on these shitters, usually something around 1.95:1 so the gears never actually work properly.

why do they always put the forks on backwards?

I think it shortens the length of the box turning them round which in turn allows them to save cardboard and pack a few more into each container.

why do they always put the forks on backwards?

I think they have a 50% chance of getting the first one right and then copy that one for the rest.

falcon derailleurs aren't even compatible with falcon shifters 🙁 its going to work really badly whatever you do with it, but it is a copy of an obsolete shimano mech. I'd suggest getting the cheapest shimano mech and shifter combination and binning the ones that came on the 'bike'