Joined: Sep 2015
Posts: 1,300
Likes: 210
From: Ottawa, Ontario, Canada
Bikes: TrueNorth CX bike, 88 Bianchi Strada (currently Sturmey'd), Yess World Cup race BMX, Pure Cruiser race BMX, RSD Mayor v3 Fatbike
Get a real race bike. The old guys are racing mostly the same bikes the elites are.
Modern tracks are a lot different than back in the day when those retro bikes were raced.
Also - don't be too attached to cruiser - some guys love their cruisers, but I just can't get comfortable on mine. Feels unwieldy. But match it to your local track - if the guys your age are racing cruiser there, then get one.