Saturday, March 17, 2012

A Requiem for .335"

I've been working day and night on my Born Free build and I thought I'd show a little piece of what goofy shit I've been doing. I'm running a stock inner primary and an old MPD finned outer primary cover on this bike. Problem is that the rest of the bike is super skinny and the '65-'69 cast inner makes the primary crazy wide. I am using a primo pro-clutch, which is in my opinion the hands-down best harley clutch on the market. The primo clutch can hold a ridiculous amount of horsepower--substantially more than what an 84" shovel will produce. So I decided to take out 4 clutch plates (two fiber and two steel) and narrow the clutch hub a corresponding amount. That would allow me to cut the inner primary down some to slim this thing up. Four plates stacked up to be .335" thick, so I decided to shave down the inner part of the clutch hub by that amount. I then had to machine down the standoffs and corresponding screws so that the whole clutch assembly had the same spring distance. Here are all the shaved down pieces:

To see how much the shave removed, look at the inner lip of the clutch hub before:

and then after the shave:

I know what you're thinking (because I thought the same thing): shit, that doesn't look like it created much room at all! Well, I mounted the rear hub up, and after measuring everything and leaving adequate clearance, I determined that I could shave a full 1.75" off of the inner primary-that is a significant reduction. Here is a pic for reference, the dotted lines show where I can cut the primary down:

Well worth the effort. Once I cut the inner primary down and modify the outer primary, I'll post some more pics.


  1. This is why you have become the cult legend you now so clearly are . . . lookin forward to layin my peepers on the end result.

  2. Crazy skills on that one.. nice work Dave..