[Closed] Can you make a bike too light?

I've never weighed, or known the weight of any bike I've ever had. I just ride the things.

whats the recommended pressure for nobbys?

No idea tbh, but at 17stone, I find 35psi to be perfect for me, if you are lighter, well i'd imagine you can go quite a bit lower! I'd experiment with it a bit, as i have higher pressure if i'm on the road alot and you can really tell the difference in skittishness if i go offroad and forget to deflate the tyres a bit.