All the propulsive thrust on the Mirage Drive must transfer through the pedal crank pins to the drums via the adjustment holes. Here it is effectively tripled by the much closer proximity of the holes to the rotational axis of the Drums, placing a tremendous compression load on those holes. Even with the glass filled Nylon V-2 drums, heavy users can eventually elongate the holes.
After years of kicking around various reinforcement scenarios, Hobie has developed an effective way to mold Stainless Steel inserts into the drums in a way that distributes this point load throughout the larger area.
Here's what it looks like:

This accomplishes two things.
First, it makes it much harder to destroy a drum by not fully inserting the pedal adjustment pins. I have done this myself without realizing it until too late. Most embarrassing!
Second, these inserts should virtually eliminate wear on the adjustment holes. I have over 250 miles of solid pedaling on these "V-3" drums with no apparent wear on the holes so far. Although relatively still new, they show excellent long term promise!
The inserts have no effect on the operation or adjustment of the Drive, and are not particularly noticeable unless you look. Nevertheless, this represents a significant improvement IMO. I understand these drums are currently being used with the new Drives. Great Job Hobie!
