I take it that with the new spine the rubber Drive Seal is not needed or can't be used?
The new spine has made the old rubber seal obsolete. I'm not sure that it would even fit (at least not well), as the ramp angle has changed on the new Drive
Safe to assume the 1/8" more depth to the leading edge reduces the "fin slap" on the hull we sometimes hear?
I don't think this is so much a fin slap matter per se, but a related occurrence. There are some combinations where the front sprocket can make contact with the drivewell rim at extreme angles, as shown here. Any additional depth would tend to minimize that tendency.
I'm a little concerned about cutting off the alignment pin. Is the alignment pin not replaceable?
Will a newer hull that uses the drive alignment pin have a problem with a pin cut off the spine?
I use my old Drives with my Revo 11 all the time. It has the pin slots and they have no pins. I've cut off the pins on the new skirt so it can used with my older boats. It works on everything. Frankly, if you know how to insert the Drive into the drivewell, the pins are superfluous. They were added just so inexperienced users couldn't insert the Drive wrong. All my Drives and drivewells are totally interchangeable.
This brings up another point. On some of the earlier
boats, it's conceivable that the skirt could be a tight fit because the Drive wasn't always perfectly straight in the well in those days. If that were to happen, a little file work on the skirt would cure the problem. With that in mind, the new spine should fit a 14 year old well.
To answer your other question, the older spine pins are removable and replaceable -- they were were like an accessory. The new ones are molded in. Because they are now reinforced across the spine, they are less prone to flexing -- this makes them more idiot proof. (it was actually possible to mis-align the Drive even with the pins -- took talent though!).
Finally do we have a part number for the new spine? Hopefully different from the old spine.
I have a cracked spine at the sprocket shaft allen screw so might as well replace it with the new model spine.
Don't know -- that's one for Hobie.