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Star hub vs Mid star

75K views 86 replies 33 participants last post by  Shaneo40 
#1 · (Edited)
Confusion at least for me there was.

Starts with the basket I got in trade that I have been lax on sharing details of the build, shame on me.

So, as the story goes I was having a hard time figuring out rear braking parts including wheels. Seems I had an iron head rear wheel and an old banana caliper. Seemed to work physically, but the wheel/tire was offset to one side about 3/4 of an inch.

I promptly got rid of the offending wheels and shelved the brake stuff.

I have been looking for a juice drum setup for a while, finally found one. Got it from a friend, a jj'er in fact. Ended up with a star hub 16"er, the spacer for a mechanical drum to mount it to the frame slide and a repop axle kit for a straight leg frame harley.

All great pieces, one problem as I'm sure you already know, they don't go together. I didn't know this at the time and I am hoping this thread will shed some light for others who are in the same boat as I was.

I should note that I have it working fine now with the correct parts and some modifications to them.

Case in point Star Hub wheel produced '36-'66 as far as I know.

Next is the Mid Star wheel produced '67-'72

Quick comparison



Also you will note that the drum side of the hubs are really different. The Star Hub is longer and houses the outer bearing, where in the Mid Star has the outer bearing in the drum. I wish I had a mechanical drum so I could show that too. The ones pictured are both 41400-67's original '67-'72 drums.


Bringing us to the axles and spacers.
Chrome repop is the standard '36-'57 rigid setup with an old drum mount/spacer for a mechanical drum.

The old patina'd setup is for '67-'72. I will make note that I had to take .250" off the rightside spacer ( the one opposite the brake drum) and had to add a .250" spacer to the drum mount side to center the wheel and align the chain correctly in my particular frame.


Notice the difference in the drum mounts.

Anyone else with some more knowledge please jump in a correct me if I missed something or miss spoke.:D

-Brant
 
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#62 · (Edited)
The bolt spacing is the same, but the hole on the '58-'62 backing plate is smaller, so the early wheel cyl will fit on the late backing plate. It just looks kinda strange with the small protrusion sticking out of the big hole.

To put the late wheel cylinder on the early plate it would require making the opening bigger. There might be a clearance issue there too with the drum.

Also, the bore size of the later wheel cylinder is larger, giving you a little more hydraulic advantage. Harley did this because the later shoes are a little wider and needed a little extra push.

edit: I just went out and looked at the both styles of shoes and both wheel cylinders. Either shoe ends will fit in both wheel cylinders. And, the distance from the mounting face to the centerline of the cylinder is the same on both wheel cylinders. You do need to use the shoes that match your drum/backing plate combination.

So, other than looking a little funny, and needing just a little more effort at the pedal all other things being equal, it should work. You could help the pedal effort thing along by using a 5/8 bore master cylinder instead of the factory 3/4" bore unit. GME makes one with the Wagner Lockheed bolt pattern that's a direct swap.
 
#80 ·
The bolt spacing is the same, but the hole on the '58-'62 backing plate is smaller, so the early wheel cyl will fit on the late backing plate. It just looks kinda strange with the small protrusion sticking out of the big hole.

To put the late wheel cylinder on the early plate it would require making the opening bigger. There might be a clearance issue there too with the drum.

Also, the bore size of the later wheel cylinder is larger, giving you a little more hydraulic advantage. Harley did this because the later shoes are a little wider and needed a little extra push.

edit: I just went out and looked at the both styles of shoes and both wheel cylinders. Either shoe ends will fit in both wheel cylinders. And, the distance from the mounting face to the centerline of the cylinder is the same on both wheel cylinders. You do need to use the shoes that match your drum/backing plate combination.

So, other than looking a little funny, and needing just a little more effort at the pedal all other things being equal, it should work. You could help the pedal effort thing along by using a 5/8 bore master cylinder instead of the factory 3/4" bore unit. GME makes one with the Wagner Lockheed bolt pattern that's a direct swap.
I'm jumping back a bit here but this struck my curiosity.

I use a WC 9005 wheel cylinder (which I believe is a 1" bore rather than the original 1 1/8" bore) on my mid star rear brake. I use the typical Wagner 3/4" bore master cylinder.

If I were to use a 5/8 bore master cylinder would it take less effort to stop my motorcycle. Right?

What if I were to use a metric MX style 14mm master cylinder? Is that too small of a bore? (5/8" is about 16mm)

I'm considering hiding the master cylinder on a new project I have.
 
#65 ·
All right, thanks all for your answers and pics.
I think I'm gonna order an older wheel cylinder then.
I have a clearance issue with the later one and my axle plate (no room for the banjo bolt if I want to keep all the adjustment room of the axle plate) and don't want to cut the fender struts mount on the axle plate...

I'm hopin' the older wheel cylinder having a flat banjo fitting it might be little less out? Don't need that much to make it work...
What do you think?
 

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#67 ·
I forget the part number, but you can get the brake line fitting connection on the other side of the wheel cylinder. I think they were for old Jeeps. Try yer parts house and see if they have books.
 
#68 ·
My Google-fu was feeling strong this morning... wish Dragon were here for an "LMGTFY" link...

According to this thread, the P/N of the Jeep/AMC cylinder is WC9004. There are also some ways to find other part #s - I'm too lazy to keep digging; think someone mentioned 'em in the thread.

Checking @ Rockauto, it looks like the cylinder in question is LF; the same cylinder w/ the fitting drilled on the opposite side should (read: "SHOULD"...) be WC9005.

Now, off the computer and on to the bike!

-WN
 
#76 ·
A drum for a mid star will not bolt to a star hub. The protrusion on the brake side of the star hub that goes into the brake drum is quite a bit bigger than the bearing bore in the mid star style drum. In a pinch, you could machine a mid star style drum to fit the star hub by boring the center hole larger and getting rid of the section that holds the bearing(s).
These two quotes are quite contradictory.

My original question was if I could bolt a left side drum brake made for a midstar to a star hub wheel.

Anybody have done it?
 
#75 ·
Front or rear, a mid star hub will bolt to the drum for a star hub, but you can't use it that way because you won't have a bearing (or bearings) on the brake side of the hub. A drum for a mid star will not bolt to a star hub. The protrusion on the brake side of the star hub that goes into the brake drum is quite a bit bigger than the bearing bore in the mid star style drum. In a pinch, you could machine a mid star style drum to fit the star hub by boring the center hole larger and getting rid of the section that holds the bearing(s).

Or if you had too many parts, access to a machine shop and a lot of time on your hands you could do this:

 
#82 · (Edited)
I don't know if it's relevant here, but I'll toss this one out,
when I put the rear backing plate I had, on my "new" Denver's rigid frame,
for my '62 FL rebuild,
the brake line would not fit, was hitting the frame, so I plugged the front
tubing connection and drilled and tapped the rear one, looks good to me,
but have not had it on the road yet.
Don't see any reason why this won't work....

And yes, I can still get a wrench on both shoe adjustment nuts...
 
#83 ·
Hi Guys,

A lot of great info in this thread, wishing I found it sooner.
I experienced a lot of what has been discussed here in this thread how ever have some additional questions.

1. What length axle? And should it be stepped?
Im running a mid star hub with the 67-72 juice drum on what I believe to be a 53 Wishbone (From castings). The Axle I have is stepped twice. Can't recall length.

2. Can anyone tell me more about the backing plate stay? At present I don't know much about this at all. Will I need to modify the frame? Again it's for a mid star in a wishbone.

Cheers
 
#84 ·
Yes Shane you need to modify the axle plate for the brake stay. John Grant at Hardtail Choppers casts up very nice tabs that look like Harley parts. V-Twin sells a stamped steel bracket and a guy with a hacksaw and a file can make one himself. The attached pic should answer your question. That is John's tab as installed by 47 Industries.
 

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#85 ·
Adding to what Mike has said above Shane, it's important to make sure you line everything up prior to finally welding it to install. I had a situation with my panhead where I tacked the tab on but the lug didn't quite sit "true square" as I thought it would, not the end of the world but meant I had to start over.

Make sure the weld is solid for the lug as that is the stay for the whole brake, without it you're in a bit of bother, and if you're running a rear brake only that could be an issue!
 
#86 ·
Rigid frames are narrower than the swingarms that had the juice parts. I still run the axle that came with the swingarm on 67-72 midstar stuff. I can get away with the original starhub axles on the rigid frame cause starhub is a starhub. Honestly, what ever fits is what I use. Spacers are whatever needs to be there to make it center and work.

Notice the midstar and starhub require different spacers for the backing plate to mount.
 
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