Mirage drive problem

The problem is the set screws holding the posts are working their way loose. I was looking at a newer model and there is a metal sleeve embedded in the sprocket - that would be much better compared to my all plastic sprockets. I think it's still under warranty, is there a way I could get these replaced by Hobie?

Ahayness welcome to the forum. Sounds like you have an '08 or older Drive -- and a good eye for detail! This is not a defect, but rather a maintenance item that you should address right away.

When the Allenhead set screws are allowed to back out, the masts can start rotating out of position and eventually work their way loose. Ultimately they can start wallowing in their sprocket holes and fall out.

You have a couple of options. You should make sure the masts are fully inserted and the flat spot is oriented to the Allenhead. The screw should be tightened with Locktite Blue to keep it from backing out. If there is any sloppiness at the mast-sprocket interface, I would recommend replacing the sprocket or epoxying the mast in. Since you're under warranty, you can probably take it to your dealer and ask him to fix it for you if you prefer.

Your other option is to upgrade your Drive with the '09 threaded masts and brass insert sprockets, also known as "v2" sprockets. IMO, this represents an excellent improvement over the previous system, but unfortunately doesn't make it defective.

Here's a link showing both systems and a cut-away view of how the Allenhead seats against the mast. viewtopic.php?f=11&t=11661&hilit=allenhead+properly+seated

I brought it up to my dealer. Not to sound terse but I think it is a defect. I've had both sprockets fail at this point. Any retighten of the allen screws just makes them looser. Locktite is designed for metal to metal fittings - not plastic to metal. It my help but I wouldn't depend on it, especially if they have already come loose once, like mine did. I go off shore with this boat and I just don't feel confident with the drive as-is. So, either way, hopefully under warrenty, I will get the upgrade.

I wouldn't be afraid to rely on the blue locktite...it does and has worked quite well in this application on many a drive.

_________________
Roger
http://www.aldenofsunapee.com/
http://www.NEKF.com/

Yeah, it may be fine but as it is the one I've already replaced went on cross threaded. They should have the set screw installed at the factory. Was a pain getting the thread to line up, as it was I never knew if it was in far enough. A metal to metal fit seems like it would be a much more positive fit. I still would feel better knowing the newer upgrade was in there..

Hi Ya Ahay
Sorry to read about your sprocket problems with the mirage drive. I have used blue locktite on the set screws with metal shafts in the nylon sprockets since 2007 and have had no loosness problems since..! I would also recommend a dab of gorilla glue in the sprocket hole if it has wallowed out due to loose set screws. I have done this with my tandem oasis on both drives with 100 percent success. Hope that helps.
Have fun out there
Kepnutz

Howdy ahaynes

Like Roadrunner sez. I'm pretty sure you would be better off upgrading to the V2 sprockets they have a different type of maintenence but there is no finicky allen scews to fiddle with.

My V2 sprockets with turbo fins have been doing very well. They do need locktite where the mast screws into the brass insert - and that is metal to metal.

A pair of V2 sprockets and 2 new threaded masts and you're golden.

Well, the dealer fixed it. I wished he'd called me first. I wanted in order and install the new stuff. Well hopefully they put locklite in there and I'll be good to go for a while. Charging me for labor but now asking about how old the drive is. It has been an ongoing problem since I bought it so I can't see how he can charge me for parts. I would have replaced them myself. I'll use these until they get loose or stop working - man that makes me nervous... Then replace with the "upgrade". Can Hobie say "RECALL"?

Andy

Andy, properly installed, your system is sound. If it starts to loosen up, you can spot it easily in advance by a simple inspection every time you pick up the Drive. I've converted to the newer system but keep the older versions as spares. In fact, I recently sheered a mast and replaced it with the old style sprocket and mast with absolutely no qualms. Additionally, I have a "racing" Drive with raked masts. It employs the old style Allenhead sprockets like yours, with masts epoxied in place (only because of the additional torque they sustain). I have absolute confidence in this unit.

Since you're planning on converting to the new style, I'd recommend ordering your parts now and you'll have them ready to install at your leisure.

I've had exactly the same problem and also had my doubts about locktite. However, since applying locktite the grub screws haven't moved a bit. (It's still a good idea to check them regularly).

The next issue I had was that the grub screw locking the main shaft that passes through the sprockets in, worked its way out. The shaft backed out of one end of its locating holes and completely out of one sprocket. (The only thing that stopped the sprocket and fin from dropping out was the chain). This was a huge problem because the shaft extended past the edge of the drivewell hole under the yak, meaning I couldn't even lift the drive out to see what the problem was whilst I was out, let alone fix it. (I carry the tools with me while I'm out, just in case.) So after paddling back to the beach (I had to paddle a hobie, GASP!), I saw what the problem was and was able to fix it when I got home, again applying locktite. No problem since.

So, definitely a good idea to remove the main shaft locking grub screw (at the bottom, in the middle, between the two sprockets) and apply locktite to that as well, to prevent a major failure there too.

Cheers,
Paul.

Your raked mast sounds interesting Roadrunner!
Who's making the Hobie engineers look like amateurs now? Any more details?
Also, I meant to ask this before but if you have broken the V2 threaded mast how did you manage to get the remaining mast stub out? I'm guessing it broke at the end of the threads?
I was thinking the only way would be to use an easy-out type tool designed for broken bolts. Drill a hole, screw the reverse threaded easy-out in and unscrew the stub. I wonder if this would work though after reading how difficult it is to remove the unbroken V2 mast?

I haven't mentioned much about it because it has some serious limitations: I'm sure it voids the warranty on the Drive, is less reliable and has some operational limitations. I'm willing to take these risks, but am not recommending it. With that understood, here's the development, which I'll keep buried in this thread with apologies to Andy for going off topic.

In an effort to keep up with you younger, faster guys, I've been experimenting for the past couple of years with allowing the fins more degrees of freedom to twist (have posted a couple of times on this with seemingly no interest from the forum). Raking the masts forward allows this to be carried out to a larger degree and with greater smoothness. It also theoretically improves the sweep angle of the fins. Here's what it looks like on paper for comparison purposes:

The standard fin position is outlined on the right here; the "racing" rake angle is shown in the middle; and I also tried an "extreme" version running 90 degrees perpendicular to the Drive axis, depicted here on the left.

This next shot shows what the raked fins actually look like. Notice how the fin clews are pulled away from their sprockets:


This provides control over the fin angle at the root, or fin pitch. This next view shows the linkage I use to span the gap. Fine tuning is done with the threaded mast adjustment:


Pluses: I constantly get about 0.1+ MPH improved speed (at fast cruise) with either modification in conjunction with the original (slightly stiffer) Turbofins. They do operate more efficiently than the factory configuration.

Minuses: The "extreme" rake version frequently scoops air with the Adventure in all but flat water, but not with the Oasis where it is mounted lower in the water. Both are worse at shedding kelp than the factory design (which is why they are angled back in the first place). Both experimental mast angles are off-axis and impose a huge twisting load on the sprocket holes which they are not designed for. They need to be monitored after each use. I managed to throw fins using a weaker epoxy than I currently use on the "racing" set, losing a fin. I have had surprising success on the "extreme" set with threaded masts using Locktite Red ("permanent" thread lock) so far. Recently I unraveled my lock ring links on a sprint with the "extreme" set, throwing both fins and losing one -- again.

There is a point of diminishing returns with increased pitch. The greater pitch angles shorten the effective stroke length as the fin uses up more of the stroke to reverse direction.

Bottom line -- more speed but less reliability and not worth it for most users. I'm still working on it.


These masts are really tough steel and they're really in there! I think there is a good chance the Easy Out would break off, so I never even tried to extract the stub, figuring it was a waste of effort.

Thanks for the explanation Roadrunner.
I had read with interest your post on the clew adjustment and extensions. I loosened mine off and was pleased with the difference.
I did wonder if it would be possible to get the V2 mast stub out. I wonder if anyone has actually done it? Broken mast reports on the forum seem to have disappeared with the intro of the V2 sprockets. I have just broken my 4th V1 Turbo mast. Must get around to the upgrade!
You are certainly pushing the technology and giving us a better understanding of the drive and how it works.
All great stuff and much appreciated!