Adding new GT fins to old drive

Hello

I have purchased the new rectangular GT fins (and new sprockets and masts) for the mirage drive on my 2009 Adventure Island. I was able to get the old fins off but there does not seem to be a way to remove the "masts" that the fins slide onto so I can add the new longer masts to accommodate the new, longer fins?. Does anyone know if the masts are removable on this vintage of drive?

I did purchase new sprockets that were supposed to accept the new masts (for the new fins) but they do not have a set screw or cotter pin arrangement to hold the mast in. They may be tapped to accept a mast with a threaded end but I can't really tell. IDeas? Did I get shipped the wrong masts.

in a pinch, the new longer fins could simply be mounted on the shorter original masts but I wonder if the 2 or so unsupported fin would flap/deform in action and undermine performance and perhaps even work and wear until they snap off. Anyone try this "make-do" arrangement until I can sort out the lack of compatability (I think) between the new fin masts and the old, and new, sprockets?

One final question, if I do have to disassemble the main drive shaft to remove the original sprockets with the new sprockets, do I have to remove the chains that run over the sprockets themselves?

I'd appreciate hearing from anyone who has made this conversion - or from Hobie.

Thanks

Duncan

The sprockets have brass at the mast insertion? There are threads down inside.

_________________
Matt Miller
Former - Director of Parts and Accessory Sales
Warranty and Technical Support
Hobie Cat USA
(Retired 11/7/2022)

Yes - they are brass and the "free end" of the mast has a slot in it - presumably for a screw driver. The masts are locked tightly in place though. I was worried about snapping/breaking the sprocket by trying to unthread the masts had they been somehow anchored permanently in the sprocket body. Given the age of the drive (12 years or so), they may very well be locked in place. I may not try to unscrew them since I have the new sprockets with the linear bearings for the new masts - hopefully I can figure out how to get the bearings to align along the drive shaft as they all fell out of the sprocket body when I popped the foam cap off the end.

I found out I was sent the wrong masts for the replacement fins and sprockets - am returning them for threaded versions that should fit the new sprockets.

Thanks for the reply.