View Full Version : Has anyone machined a 13 spoke cast rear wheel?

28th January 2012, 14:56
Just wondering if anyone has had any experience with machining down the hub of a 13 spoke cast rear wheel?

I'm planning on installing Vulcan mid glide triple trees and a 16"x3" 13 spoke cast rear wheel to replace the 19" front wheel on my 2001 Sportster 1200S Sport. I've worked out i'll need to machine down a little over 4mm off each side of my rim's hub to get it to fit between the mid-glide forks and line up the dual disk brakes into the calipers. But having never seen or heard of anyone doing this (Mid glide + 13 spoke rear cast wheel + Dual disks), i have no means to know how much "meat" i'll have left after. Not to mention if its enough to maintain the structural integrity of the hub and be safe to ride.

I know I could just opt for a wide glide instead which will solve all my problems, but i prefer to stay with a mid glide if i could unless i have no other choice.

Anyone had any experience with ths?

Cheers! :cheers

28th January 2012, 23:47
i do not think you will have a problem. you will have to respace the bearings however but should be no biggie. while it is off, smooth down the cast look hd left. that is nothing but a dirt trap and it looks better smooth.

29th January 2012, 01:09
I think you're about right on your calculations. I have an 06 and put the rear wheel on the front with a wide glide front end and it just barely fit. I made my own caliper mounting bracket for the brake.
I don't think you'll run any risk with narrowing the hub width to fit the mid glide, but finding a lathe that can mount a 19" wheel may be a problem and quite expensive.

29th January 2012, 01:48
mounting the wheel should not be a problem, you do not need to turn the wheel. a bridgeport style mill will work.

29th January 2012, 02:02
A mill will narrow the hub, but make the whole wheel useless. The lip that centers the rotor will be gone, and half the relief that the bearing fits in will be gone. The only way that I see to recreate the outer hub configuration is in a lathe.

29th January 2012, 02:38
It can be done on a Bridgeport. You can use a rotary table and a boring head to do all that needs to be done. Pull the bearings and see if you have a enough material to counterbore the bearing bores .1574" / 4 mm deeper.

29th January 2012, 04:10
Allright, I'll concede to the fact it can be done on a bridgeport, it wouldn't be my first choice, but it can be done.

29th January 2012, 06:06
Thanks for the replies folks!

My wheel is actually an older AMF-era FLT wheel (P/N 41121-79) that is offset on one side. I already have a hub spacer to account for the offset, so i just need to machine down about 4.62mm off the other side to keep the rim centered.

It looks like it has enough meat on it as far as the rotor mounting bolts are concerned. What i'm not sure of is the bearing seat.

Do any H-D cast wheels have hollow internal spaces that might not be visible externally? I don't want to start machining the wheel and then poke a hole into an empty cavity where the bearing should be sitting. :doh

I too was thinking a lathe would have been the right tool for the job. I think its time i gave my local machine shop a call to find out if they can handle the size of the rim.

29th January 2012, 11:43
the bearings will have to be sunk back in and the spacers cut to reloacte the bearings. there are numberous ways to mount the wheel on a bridgeport type mill and cut a radius. we take flat aircraft aluminum bar and cut 180 radii on the end to make pull fingers for steel guitar strings just using a vise and a stop jig. one simple way is to sink the lip first with a hole cutter, fly cut the rest and then go back and cut the lip to spec.

you can do like we do on pull fingers. the wheel is put in fixture like was brought out (rotary table) and the fixture is offset so the fly cutter butts to the original lip and the wheel is rotated. many other ways, put the tom terriffic hat on and think (who remembers tom terriffic).

29th January 2012, 12:32
I've fabricated a few things in my time, but mainly used mechnical intuition and common sense more than anything. I'm not ashamed to admit the only thing i really understood from that last post was the first sentence. :laugh :confused:

Nonetheless, my main concern is still if there would be enough material left to properly seat the bearing. Chances are, everything will turn out right. But just for reference, my wheel looks exactly like this...