Question on reach weapons

[Battalion]

What does the effective range become on a reach weapon if you become enlarged while using it?

[Nebo_]

Assuming you were medium to start with, 20'.

[MeklorIlavator]

Remember, reach weapons double one's natural reach. For medium creatures, that's 5', so a reach weapon makes it 10 feat. Depending on the large creature, the reach varies, but I believe Nebo gave sufficient explanation on that count.