# Warning/Mirage drive grub screws



## Nhibbo (Mar 15, 2009)

Hi fellow Hobiacs,

Just a brief warning on fitting ST fins to your mirage drive. When I fitted mine, all went well and it has had 2 years of heavy use since. Last week though, the stainless leading edge rod of one fin dropped out. This left no ability to move forwards at all, even on the one remaining fin. The yak just rocked from side to side. As mentioned by a few others, outbacks are not easy to paddle and fortunately I had a tail wind and sea to help me get home. Could've been much more troublesome with an offshore wind as we've had so often lately.
Cause: 1. Lack of maintenance-I had never checked the tightness of the holding grubscrews since installation 2 years ago.
2. Being a very tight fit, the shaft was probably a little off centre when installed and the screw tightened. Over a
long period of time, the shaft rotated and the screw was therefore loosened and continued to loosen.
3. Lack of maintenance-sure I always cleaned and sprayed the drive with WD40 before putting it away, but I 
never checked those screws.
Conclusion: CHECK THE TIGHTNESS OF THE GRUBSCREWS ON YOUR MIRAGE DRIVE (especially before and after a long haul trip).


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## Bartek (Dec 12, 2007)

Nhibbo I believe you can upgrade the masts to the latest screw in design which will prevent this happening again


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## Nhibbo (Mar 15, 2009)

Thanks Bartek,
Will check it out


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## MrFaulty (May 15, 2008)

Had the same happen to me off Broughton the other week in my revo, not too bad to paddle but I felt it the next day - nowhere as easy to paddle as my VFTi whcih I can paddle all day and not feel a thing!


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## Bart70 (Jan 28, 2007)

Bartek said:


> Nhibbo I believe you can upgrade the masts to the latest screw in design which will prevent this happening again


The drives with the grub screw are the V1 model drives. The newer V2 drives have a tapered thread mast that screws in rather than being held with the grub screw - a much more sturdier design.

If your drive has had a bit of work....consider doing an upgrade from a V1 to a V2 by changing the appropriate components on your existing drive. I had this quoted once and cannot recall the approx cost....but it brings your drive up to the specs of the V2 - Which not only has the better mast fastening but is also a stronger, smoother unit with redesigned cables/chains to further reduce fatigue stress on the cables/chains.

Might cost a couple of hundred but you will have a stronger and potentially more reliable drive. I already have one V2 drive - when the cables need replacing on my older V1's I will do the upgrade without hesitation.

I would strongly recommend to anybody replacing the chains/cables to think about buying the extra components and upgrading to V2 - particularly if your yak gets a lot of heavy use and is used offshore.

Your friendly Hobie dealer should be able to assist. 

Bart70


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