adapting pushchair to suit an 18 month old?

[SevernTrentWater]

I hae an 18 month old son who is walking and still have the buggy set up for a young baby, the front of the seat is up and it has a bar across the front. It's a bit of a tank because it is designed for 0-3 years. I'm wondering what age can i drop the front seat into 'normal' buggy position and remove the safety bar if at all. The problem is he's really short for his age which means I'm not sure about dropping the front.
Also, at what age can I think of buying a little stroller for getting about town quickly because my pushchair is a tank.

I'd suggest getting a stroller and mini micro scooter right now. Your dc will be up and away in no time.
Only problem is lack of decent shopping space under a stroller, but getting your child moving is such a big step!

what pushchair is it?

you'll be fine to have it as a normal seat now, he is quite old

Does pushchair have harness? if so, get shot of that bar, put the foot rest down and let him learn to climb in.