What size wheels/tyres can you get under a Velocity?

I have 15" wheels on mine with 45 profile tires and they work very well. The Velocity can take 16" wheels as the kitcar project build used them a few years back. However, I fitted 16" wheels to my last kit and it looked great but was skittish on the road. So I recommend sticking to the standard 15" size as recommended by Luego.

Also 15" is very very common size which gives you a huge range of tyres at reasonable prices.

Check out the difference between the same tyre and profile, in 13, 14, 15, 16, 17 inch diameter, and you will see what I mean.