T wire wheels fit on the front hubs without brake drums since there were no front brakes. Model A wire wheels fit on the brake drum which gives it support. I've been told the wheels can flex without the drum. How does this work when using adapters for A wheels on the front of a T? Reason I'm asking is my friend has some A wheels he wants to put on a hot rod he's building and keeps asking me about how to put disk brake rotors/ hubs on the wheels. I told him the A wheels need the drum or at least part of it to support the wheel, but maybe not. I also keep telling him to get on the HAMB forum but he is computer illiterate. Now I'm wondering how the A wheels work without the drum. They don't look much different than T wheels to me, but I've never really looked at a T wire wheel up close.
You are probably right that the A wheels need support, because I have seen many broken model A wheels.
Don't know much about any engineering on adapters for wheels, adapting A wires to wood T hubs or other combinations of fitments, as most are a compromise IMO.
Do know the Model T wire wheels have a "Dixie" cup taper shape or cone on the wire wheel center.
That cone shape center fits snug to the long 'nose' of the Model T wire wheel hub.
Note the section of machined nose on the hub, near the end.
This machined area on the hub fits snug to the inner center section of the wire wheel.
The Model A Ford and early (AR) wheels and hub are similar somewhat in design, as these A wheels fit to the machined ring at inner section of the Model A brake drum.
The reason for this design too in the Model T wire wheel and Model T wire wheel hub is that a lot of lateral forces are on the long spindle on the front axle. The snug fitting of the wire wheel on the long nose of the wire wheel hub provides strength.
The hub bolts retain the T wire wheel, but that important feature of the long nose T wire wheel hub provide security. In fact on some of my installs with powder coated wheels, had to Dremel away some excess coating from the bore of the T wheel centers to fit to the T hubs! The fit is that good on the long nose of the Model T wire wheel hub.
IMO stay with Ford engineered and mating parts, put Model T wire wheels on Model T wire hubs. Especially on the front, as all that load and forces in turning the front wheels, steering and cornering is on those front spindles, and front wheels need to be fully supported on their hubs.
The first model As didn't have separate emergency brakes, the regular service brakes were used for the "parking" brake. When the separate emergency brakes were added, it changed the shape of the rear brake drums (to allow a separate "drum" surface for the emergency brakes). The first wheel design would not fit against the new drums at the hub edge. Ford issued a new design wheel, as without the edge of the wheel center against the brake drum, the wheel hubs would crack.
SO, yes, there are reasons to worry!
Adapters are available made to address the support issue. Speedway handles them. I have a Ranger truck chassis I'm using as the basis for a 1930 Miller Indy roadster build. The adapter can be had with the support ring machined on, or the support rings can be had seperately to fit the flat-faced adapters in the pattern you are using. 1930 A wheels on the 98 Ranger-
Gary is correct they need a support coller or ring as shown at least on the front wheels
I drove a couple of speedsters a lot of miles with model A wheels.
If you keep in mind that sliding off the road or hitting big chuck holes will mess up your model A wheels you shouldn't have any trouble.
However, I used a 3/8" plate between the wheels and the T hubs as big as could be done.
That also solves the problem of the a bolt holes being too big for the T hub.