For comparison of wheel and tire combinations I have measured some of the offerings used in some of the plastic 1930’s kits I have. This may be of some use, or may serve only to add valuable confusion.
Model Wheel Diam (mm) Tire Diam (mm)
Airfix 1930 Blower Bentley 16.65 24.66
Pyro 1930 Blower Bentley 16.9 25.13
Pyro 1934 Bugatti Type 59 17.09 23.38
Pyro 1931 Alfa Romeo 1750 Grand Sport 14.86 22.77
Pyro 1931 Aston Martin International LeMans 16.00 25.37
MPC 1933 MG K3 Magnette 16.45 22.09
Original wheel/Tire sizes during this era seem to have been a bit of a mish-mash from the manufacrurer’s. For our practical purposes, except in rare cases where you are able to make your own wheel/tire sets, we will be pretty much be limited to the tall/tin wheel/tire combinations that are available to us.
Currently that’s:
1. (and so long as he is willing to make them) a DArt Custom with a wheel Diam. of ~16.34mm and a tire diam. of ~23mm untrued. Based on the above chart these might look a bit small on some cars and a bit large on others but in all cases are certainly within reason. If they look tall just true them a bit.
2. Another source is RS Slots in the UK. They offer 3 vintage wheel tire sets. All three of their wheels are 16mm dia x 3.25mm wide with 2.5mm boss for grub screw. That’s pretty much the DArt size. Their inserts vary by spokes, 36,48 and 60. Tyre choice is small sport (21.4mmx 2.8mm wide), medium road (20mm dia x 3.15mm) or large road (22.15mm dia x 4.4mm wide). There is no mention as to whether the tires are urethane or rubber.
So as far as standardizing, wheel sizes in the 16-17mm. diameter range with a max. tire diameter of 23mm. should seem to be appropriate for a start. These are right in line with Art’s current thoughts and current DArt or RS Slots vintage wheel/tires and will probably be what we can get our hands on for most practical purposes. You will probably want DArt tires unless the RS Slots ones are urethane.
… Mr. Birkin is running the Blower on the test stand as I write this.