I would like to put a 21" single disc laced wheel on my 03 Electra Glide. Can I use a Softail hub like the one that is on a Heritage? Will I need to change the spacers or axle?  

Chengwi:
Doing a single disc laced wheel on a bagger is actually a very easy task. No you do not use a hub from a softail, many companies such as landmark make laced wheels for baggers with single side discs. Landmark, RC, PM, Roland Sands, and just about everybody makes single rotor wheels, and what they are doing is taking the exact same hub as a dual disc wheel and covering, and smoothing the sides, as well as filling the rotor bolt holes.

With the wheel choice made some other important decisions need to be made. First of all since you are eliminating that rotor and caliper on the right side, are you gonna buy a shaved fork leg? If you do you might as wheel put a chrome front end kit on it since you will have it all torn down. It is a nice complement to that wheel you just spent some money on.

Another step to consider is since you will be eliminating a rotor and caliper, you will not need that side of the brake line. A one piece brake line is fairly inexpensive, and if you put the chrome front end kit on you may consider a stainless braided line. Looks GREAT!

If you have ABS you will find out real quick that it may be more expensive than it is worth, and that maybe it would be cheeper to stay with two discs.

If you still are thinking you want to go with a single side disc, safety is something else that we cannot turn a shoulder on. Since you have 2 11.5 inch rotors on there from the factory and we are talking about getting rid of one, it makes since we are basicly cutting your front brake stopping power in half. To remedy this, there are several different ways I will start with the best way, and continue to the quick fix.

1.) Change your master cylinder to a softail. The softail master cylider is 11/16" bore allowing for a softer brake lever. The next step would be purchasing a 6 piston caliper from Hawg Halters, Jay Brake, PM, or many other companies. The last step would be purchasing a 13" rotor, and MAKE SURE THE CALIPER IS COMPATABLE WITH A 13" ROTOR! This is by far your best option.

2.) Some say you are just fine with a six piston caliper and 13" rotor without changing the master cylinder. The lever is still to stiff for my liking, but thousands of people run it this way.

3.) Softail master cylinder with a 13" rotor. If you do this however you will need a converter bracket to raise the cailper up for match the 13" rotor. This is available throw drag specialties.

4.) The cheapest option and the one I do not recommend is just putting a softail master cylider on with a 11.5 rotor (11.8 if you have an 2008 or later) This to me is way to stiff and not enough stopping power beings your 80% stopping power is on the front brakes.

5.) And last but not least do not in no way shape or form run a stock master cylinder with a 11.5 or 11.8 rotor and stock caliper. This is not enough, and many people choose to go this way because it is cheep. However its so stiff that if you ever got into an oh *** situation you would lock up that front wheel and the rest is history.

I hope all this information helped I know its a lot but safety is something to think about it, and if you do it right theres nothing cooler than a big wheel with a whole side open and a chrome six piston caliper on there. Looks awesome!!!! Good Luck