Originally Posted by steelbikeguy

I had that same question a while ago, and got an answer here: Hi-E

There's two tapered roll pins on each side that affix the crank arm to the tube/axle.
The pin that is oriented perpendicular to the crank arm is just shoved through from one side to the other.
The other pin is installed inline with the crank arm. I'm not sure how you get it back out.

It's not the worst way to be able to use a hollow tube for the axle, but I have questions about how well it held up. Harlan seemed to be designing with low weight as the top priority, and with durability way down the list.

Steve in Peoria
(but my Heavy Duty Hi-E hub is still being used)