Ford wire wheels on new 21A-1125 drums
 

I purchased new 21A-1125 rear brake drums for my '33 with 47 hydraulic brakes. I have 16inch KH wire wheels and will use wire wheel support plates. Bolting the wheel on the hub-drum I find that the large wheel diameter does not make contact with the drum. This results in the wheel only being supported on the face of the drum. I am concerned that the wheel will not be sufficiently supported. Are my concerns justified?? If so, do you have a recommendation to overcome the problem??

Thanks for your thoughts.

Re: Ford wire wheels on new 21A-1125 drums
 

Your concerns are justified, the wire wheel is not supported properly if the outer of the center is not in contact. They were designed to have 3 points of contract. One just inside the studs, one just outside the studs and then the big outer part of the wheel hub section.
I haven't played with the repro drums so don't have the solution for you, sorry. But just backing up your concerns.
Martin.

Re: Ford wire wheels on new 21A-1125 drums
 

If you have a look in the "New member, suspension identification" thread, their is a pic of a 1935 drum, you can clearly see the 3 points of contract I mentioned.
Martin.

Re: Ford wire wheels on new 21A-1125 drums
 

You will need the proper support "rings" between wheels and drums. You can get these rings from various suppliers or make your own from 4" OD galvanized water pipe or black iron pipe cut off in a lathe to a length of 0.185" to 0.190".

Re: Ford wire wheels on new 21A-1125 drums
 

Scooder I will check out your suggestion. Your first comments address my concern about the 11-1/4" dia.

JM35 I have those support rings in the form of a flat piece drilled to go over the studs and a raised surface so there is contact inside and outside of the studs on the wheel. I am now talking about the large diameter approx. 11-1/4 inches which is the third point of contact as Scooder said in his first comment above.

Re: Ford wire wheels on new 21A-1125 drums
 

I hate to speak against anything written by my friend Scooder, but a real world reality check is called for. YES, in the original design, the outer part of the centre hub is supported by the original drum, but Lots and lots of wires have been run successfully on the later drums over the last 60 years. When you take into account the relatively low mileage these cars now do and the tendency not to overload or abuse them (too much) then, particularly when the OP wants to "do the right thing" and use the spacer ring that addresses the mismatch at the centre, than my feeling is that wires will work ok without the outer part of the hub supported.

There is a secondary consideration, too. The early drums were fully machined on all three contact surfaces (like Scooder says, clearly seen in the other thread currently running) But the later stock drums, although shaped generally to allow a wire wheel to be bolted up, are not machined on the outer surface. So if you did bolt a wheel up and contact was made at the outer surface, then if the contact was not even, then theoretically the hub or wheel could be distorted from the contact.

I'd say as long as the correct spacers are used to support the centre, then bolt em up and run em.

Mart.

Re: Ford wire wheels on new 21A-1125 drums
 

The plates with stud holes and intragal ring support are normally used with the new repro drums and hubs that have longer studs. Maybe these are what you have and I misunderstood your first post. If the plate type spacers are used with original drums there may not be enough thread for full lug nut engagement. There have been previous posts on this subject with explanations by Richard Lacy, Early V8 Garage.

Re: Ford wire wheels on new 21A-1125 drums
 

This is one of those posts that needs a picture to clarify the question. I was under the impression that there was an issue with 35 wires on the repo 21A style drums. This was due to the design of the drum taper that was to shallow to allow the bolt flange to flush mount at the hub flange and a gap was created. The shallow taper design based upon the fact that it was a thicker casting caused the outer portion of the hub rim to hit the brake drum and prevent the wheel from fully seating on the hub and produced about a 3/16" space. This space had to be taken up by a wheel spacer and longer studs had to be installed to compensate for the change in dimension. The repro 21a drums work ok with steel wheels but to use 35 wires you should be using 40-46 stock drums. Can you use the repro drums, yes but you will need to install new longer studs and make a spacer to take up the gap. The normal spacer/support sold to be used with wires to the stock 40-46 hubs I dont think is still thick enough for the clearance necessary on the repro drum.

Re: Ford wire wheels on new 21A-1125 drums
 

Dick Spadaro to the rescue!

Re: Ford wire wheels on new 21A-1125 drums
 

Larry, I would suggest contacting Richard Lacy at the Early V-8 Garage in CA. I believe a major part of his business is hydraulic brake conversations for early Ford V-8's.

http://www.earlyv8garage.qpg.com/

Re: Ford wire wheels on new 21A-1125 drums
 

I was under the impression that the 16 inch bent spoke Kelseys mounted ok onto the 40-48 original drums without the need for spacers. Is this correct?

Re: Ford wire wheels on new 21A-1125 drums
 

The 16 inch Kelsey's were designed to be the same as the '28-'35 wire wheels and need the spacers.

Charlie Stephens