Originally Posted by
Jipe
There are indeed few tires available in ETRTO 355.
Besides the Shwalbe, there are also Panaracer Minits Lite PT in ETRTO 355 but they are very difficult to find outside Japan.
There are also some BMX tires in ETRTO 355 most of there are very wide tires (more than 50mm wide and won't fit on the Birdy I think).
I changed my wheels for ETRTO 349 (Brompton wheel size) that is only 6mm smaller because there are now much more tires available in ETRTO 349 than in ETRTO 355.
IMHO, for the typical use of the Birdy as a high quality, convenient folding city bike, the Marathon can't be beat. It has great durability and puncture protection, and has width enough to be safe on bad pavement and gravel. It's also good for touring, for the same reasons. So for that purpose, 355 is fine. For racing / fast training, offroad, or other specialty use (for a folding bike), 355 or 406 gives more choice, and cheaper tires. For racing 28-406 is ca 2 cm larger in diameter than 44-355, as is a balloon 55-349, if that exists. A 349 much narrower than 50 mm would be smaller than the 44-355.