When I got to play with the new Hobie inflatable back in August, there were some subtle changes with the Mirage Drive that came with it. As a big pedaling fan, this caught my attention and I was able to "borrow" it for an extended use.
I found some significant changes. The drums and chains have been redesigned to provide several improvements.
This first picture shows the difference between the old (left) and new drums:
There are more differences here than meet the eye. Let's take a look at some of the features.
Improved crank arm support:
Notice the larger pockets. These support the crank arms much better than the old drums. Together with the newer crank arms, virtually all flexing is eliminated.
Redesigned cable ramps:
Looking closely at the picture above, notice that there is no angular change at the cable swedges (where the cable connects to the end piece) on the new drums. This relieves uneven stress on the cables at their weakest point. Excellent design change!
"Waffled" back sides:
The current drums are vulnerable to warping due to uneven cooling as they are popped out of their molds. This waffle pattern allows more even cooling for minimal warping. Structurally, this pattern supports excellent rigidity with light weight. Here's what it looks like:
The new drums reduce overall pedal width by about 1/2". Whereas most users wouldn't notice the difference, long legged owners in some Hobie kayak models will find that, with the new drums, the Drive no longer rubs against the side of the cockpit in the #7 hole. Coincidentally, this narrower width is very similar to that of the venerable old stainless and aluminum drives. The following pic. shows the difference in pedal width between current (left) and new drum drives:
Slotted holes (not shown).
The cable holes are now slotted instead of round to work with the new cables. See below.
Longer cables with clipped threads:
The new cable ends are shaved on opposite sides in order to fit through the narrow drum slots. As a result, they can no longer twist. For anyone who has tried adjusting their cable tension, this simple change makes the process much quicker and easier! There is no longer a need to use pliers or vise grips. With just a wrench, you can now make quick and easy one handed adjustments. Nut locations have also been moved for easier access. All three cables can easily be adjusted in less than a minute. Here's what the clipped threads look like:
As was briefly mentioned above, crank arms were redesigned earlier this year to provide more rigidity, improve the pedal shaft and secure the top caps. Used with the new drums and chains, the possibility of pedal flex or pedal adjustment pins popping out is virtually eliminated. In three months of heavy pedaling, I have experienced no pedal flexing and negligable adjustment pin wear on the drums. Reliability has been 100%. When the dealer wants his "demo" unit back I plan to make sure both my "modern" drives are updated.
My understanding is that these new drums and cables are standard on the inflatables only and are not yet available in the parts system. This is apparently due to limited cable availability. When they reach full production, perhaps Hobie will offer upgrade kits, as these will make a significant improvement!