Technical Front Brake Hub Offset

Sometime in the past I put F1 [51'] brakes on passenger car [48'] square back spindles. I am thinking that since the F1 brakes are wider there would be a slight tread width increase? Any one remember how much?

 

About a 1/16" difference to the hub face.

 

Perfect, thank you. I do not have the drum and backing plate off, my measuring is from wheel face on the drum to spot face on axle side of spindle so is rough; I get a little over the F1 dimension in pic by around .075. The disc brake rotor [speedway kit 91031909] I have is less than the 40' ford pic dimension by quite a bit. What I need to achieve is that the wheel ends up in the same place as with the F1 drums, to clear drag link tie rod end which is pretty much tucked where a standard clip on wheel weight would go. Seems I have to add about .400 to rotor face.

 

Here are a couple measurements of a F-150 rotor (Speedway kit) mocked up on a spindle.

The first is wheel mount surface to back of rotor and the second is back of rotor to spindle flange.

The second has to be subtracted as the rear face of the rotor is behind (inside) the spindle flange.

Puts the wheel mount surface at about 3-1/8" which would be about 3/16" narrower than an F-1 hub and drum.

Didn't have any problem with tie rod clearance on the installs. On one install the arms were bent for drop axle swing; but the eyes remained at stock width. The other we used CE bolt on arms in our own way.

Maybe this will help with project?

 

I just went back and forth from your pics to my assembly and the dimensions are the same. So a 3/16 spacer should put the wheel in same off set as F1; and the wheels are just hitting the calipers [because they are reversed] so should give the necessary wheel clearance. Couple pics to show why wheel placement important. Thank you very much!

 

I see you have a different steering arm configuration that changed things; the stuff we did used retained the rear drag link connection.

There were a couple "lumps' on the GM calipers that kissed the wheel; but a little grinding provided adequate clearance.

Looks like you have it under control.

 

Thanks for the help!

 

That is one impressive steering arm. Are there some pictures?

 

Old theory of mine; when in doubt, make it stout. I'll see what I can do for some pics.

 

Here is a couple three, I don't want to get off post too far.. Thanks for interest.

 

Thanks…