What is a fulcrum clip?
 

I am trying to fix up an old Sturmey Archer 3 speed hub, and the first step in their manual is to check the fulcrum clip. I have no idea what it is, and a quick search brings up this part, which I do not see on my bicycle.
http://www.sjscycles.com/store/sturm...nclipsmall.gif

Can anybody fill me in on the function of this thing?

Never mind, I found it further up the chainstay. I was looking all around the hub.

It should actually be on the top tube. It holds the Fulcrum Sleeve. There's a picture here.

i have 6 3speeds, all with s.a. hubs, and thats basicly a cable stop. yeah, most time there is a plastic or metal fulcrum insert that fits in the clip, but some work with the end of the shifter cable housing just fine. its function is to hold the cable/housing to the frame and to set a point at which you can meter for your gear adjustment. lets say you have your shifter cable/housing ready to connect to the indicator chain coming from out the hub's axle. i connect the end of the shifter cable to the indicator chain with the shifter in 3rd and then slide the fulcrum clip with the end of the shifter housing in the sleeve, slide it up the chainstay (or however your cable routing is) untill i've taken up the cable slack, but not too tight to as actually shift.

in short, think of it like a newer bikes braze-ons for cable guiding/stops. once tightened to the frame, can be slide for/aft to set the basis for your cable adjustment and tension. the finer gear adjustments can be done via the furrowed sleeve and indicator chain's adjustment "nut".