Nano with 406 rims, 20" x 1.95" (50 - 406) tires. These are very used rims off a cheap kid's bike with Kenda Kontact BMX tires.

Q: Can the (pre-production) Nano fit at least 2.0" tires?
A: No. Probably 1.75" max.

Front, enough clearance:


Rear, just rubbing on left, maybe 2mm space on right -- NOT ENOUGH CLEARANCE:


Bike with 406 rims and 1.95" tires -- bitchin':