I did a lot of searching for this topic but could not find a clear answer. I have seen a lot of people talk about using Schwalbe Big Apple 16" tires on Strida 5.0 and newer bikes. I want to know, however, if they will fit on the older Strida 3.2? It doesn’t seem like there will be enough space between the the side of the tire and the belt. Thanks for your help.
Welcome purple_clouds!
Funny thing…
Yesterday I’ve got a pair of Big Apples 16" x 2,00.
They fit, but I have a 5.xx Strida… 
Tyre - belt distance ~ 10 mm.
@Blackstridaaustria, how this upgrade changed your bike behavior ? Does the speed goes down ? Is it much softer now comparing to stock 16 tyres ?
Welcome mico,
A lttle bit less nervous, caused also by the lower maximum pressure of these tyres, I guess.
(I’m used to inflate each tyre to it’s max. pressure.)
Said honestly; I didn’t ride very much on 16" wheels since the change to 18".
Due to the higher gear ratio of bigger wheels the speed should raise (at equal cadence) - in theory.
In practice I would say no, except at low tyre pressure.
The Apples are for sure more comfortable than Kenda.
(Compared to 18" Kojak at 8,0 bar they’re different like heaven and hell!)
My favourite tyres are still 18" Kojaks, naturally I don’t ride on sand or gravel roads…
Please may I ask what kind of roads you have to use (or prefer)?
Thanks for the detailed answer, @Blackstridaaustria
Road type varies from park footpath about 20% to asphalt roads. The problem is that asphalt quality is not very good sometimes that is why I bought Brooks saddle which helps a lot.
The other problem is that Big Apples 16 are out of stock in the shop where I’m going to buy tyres (CRC). But there are cheaper Continental Explorer 16 which seem to be good too. And I guess they fit better for park lanes.
Gladly, dear mico 
Yes, why not Continental, please report about your experience.
Please note also that you will need:
-
Most likely a different tube size.
Schwalbe tubes -
A small modification for proper function of the magnetic folding mechanism.
Here’s more about the magnet mod:
Make wheels further apart when folded (redux)
Re: 18" Wheel Upgrade: not that easy…
Re: 16" custom wheels, radial 36 spoked