Hobie Forums :: View topic - Straightening a Bent Mast on Your Mirage Drive

These new sprockets are really tough. Unless they show some problem, I would feel comfortable continuing to use them.

If you look at your thread pattern on the masts, you'll see that it is not conventional. Additionally, the SS on these masts is pretty tough (Don't know the # is). So I wouldn't invest too much in machine work -- you could end up with an inferior product with a thread pattern that might be destructive to the threaded brass sprocket inserts.

BTW, I have a couple of the old SS sprocket Drives and used them for years. They are very strong but as Matt indicated they have their Achilles heel. They rarely get used these days since the "V2" Drive came out. IMO, Hobie's current ('09) Drive is their best ever without question -- easier to maintain, more reliable and more durable (provided they stay away from those submerged boulders). :wink:

Author:	Roadrunner [ Tue Jan 27, 2009 1:10 am ]
Post subject:	Straightening a Bent Mast on Your Mirage Drive
Sooner or later most of us will likely strike something with our Drives and bend a mast. It's pretty easy to straighten but, depending on which of 3 sprocket styles is in use, there are different methods available. The current ('09) sprockets (top sprocket below) have brass inserts and are stronger than the earlier plastic versions. Straightening a threaded mast by hammer or vise would risk damaging the threads, so I prefer to bend it in place (without removing it from the Drive). Although it can be bent freehand with the hands, you get better results using the smallest pipe that will sleeve over the mast. This keeps the shaft straight while it is being restored. Since our masts are 5/16", I was lucky enough to find a 3/8" pipe at a local salvage yard and combine it with a 5/16 brass sleeve to take up most of the remaining gap. Fortunately, most masts bend backwards (the direction in which the boat does not yield), and that's the easiest direction to correct. After removing your fins, measure the distance between masts at the base. Planting the nose of the Drive on a solid surface, bend the tip until the distance is comparable at the tips. Bending sideways is riskier and rarely needs to be done. Small variances can be adjusted out by re-centering the cable/chain. If you have to bend this way, split the fins to their maximum, then apply pressure to the side. Understand that you may pop a cable swedge loose -- be careful. ______________________________________ For those who have '08 and earlier plastic sprocket with Allenhead lock screw (top picture, lower sprocket), I recommend removing the mast and straightening it with a hammer or vice. There is a risk of splitting or weakening the sprocket if attempting to straighten without removing. When reinserting the mast, pre mark the flat spot (see below) so you'll know when it is facing the Allenhead screw. Tap it to make sure it is fully seated. If it is wobbling in the sprocket, you should either replace the sprocket or apply epoxy to stabilize the mast (or risk having the mast fall out when you least expect it). Locktite your Allenhead lock screw in and make sure it is fully seated -- check the other one while you're at it. Screws that are not fully seated (left, below) or that back out are the primary problem areas with this style of mast. You can tell by the final depth of the Allenhead screw. The above picture shows the screw properly seated. ---------------------incorrect-----------------------------------------------------correct------------------------- ___________________________________ Anyone with a stainless sprocket (below) can straighten their mast by with any method -- in place, vice or hammer. In any event, it is a good idea to change the cotter pin mast retainer at this time, as it takes a lot of stress. _____________________________________ If your ST or Turbofin tears through the side (and are the newer tougher material that has been used for the past year), it will generally stretch first so the tear is at least 1/2" away from the mast tip. If so, you should be able to slide the fin back on without any problems or further action. Just be careful slipping the mast past the hole. PS: All sprocket styles are still available from Hobie and may be adapted to any Drive. The Brass insert sprockets however, must use threaded masts. Any mast used with a stainless sprocket must have a hole in one end for the cotter pin.

Author:	bjb [ Tue Jan 27, 2009 5:05 pm ]
Post subject:
Another excellent post RR to add to my file. Thanks If the masts need to be removed from the threaded '09 sprockets, how do you recommend doing it without scoring the masts. I know the application of heat can loosen the loctie but I wouldn't want to compromise the plastic.

Author:	Roadrunner [ Tue Jan 27, 2009 11:59 pm ]
Post subject:
I've used double (side by side) vice grips set very tight, a large screwdriver and lots of elbow grease. Any marks on the standard mast can be filed or sanded off if the masts are to be re-used. You might try removing them shortly after a session in the water. I understand more recent Drives have less Locktite and are easier to remove. The reason for the Locktite is that the masts will not stay in place without something to keep them from unthreading; Pressure alone will not do it. Obviously, it's very important to Hobie that the masts do not depart the Drive in an untimely manner, so better safe than sorry! I concur 100% and use Locktite now on all threaded Drive components including metal to plastic. It is my opinion that Locktite may lose some of its strength over time in a marine environment. I've observed it crack, fade and leach to some degree. Also, once disturbed, it can not be depended upon again without a new application. So I use it generously and haven't had any Locktite failures on any threaded surfaces to date. Once set up, you don't want things spontaneously changing or falling off!

Author:	stringy [ Thu Jan 29, 2009 2:30 pm ]
Post subject:
Thanks again Roadrunner! Have you managed to successfully repair the tear in those fins with the mast popping out? My original model turbo's have both suffered that problem and it is getting worse. The most successful solution I have found so far is gaffer tape but it needs regular replacing.

Author:	Roadrunner [ Thu Jan 29, 2009 5:07 pm ]
Post subject:
Stringy, I haven't had to do a thing! At first I taped it and like with your experience, the tape worked loose after awhile. So I just removed the tape and this is what the fin looks like now: Here's another one on the other mast: These second generation Turbofins are really amazing -- tougher yet more flexible, they resist scrapes, punctures cuts and tears better than the originals. When they do puncture, as in the above cases, they stretch quite a bit first which gives you plenty of margin when resetting the fins (without having the mast tip pop out again). There has been no propensity for the tears to expand as I had feared. They're still not quite as tough as the standard fins, but a heck of an improvement over the originals. BTW, these have been in production for over a year now so any recent purchases would almost certainly be this improved edition. It's very difficult to tell the difference by looking -- these are a little darker black and a little floppier if you were to compare them side by side. For patching, I used to have some Liquid Rubber but ran out and haven't seen any around lately. I don't know of any tape that would permanently stick to these fins, probably due to the constant flexing.

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Straightening a Bent Mast on Your Mirage Drive http://www.hobie.com/au/en/forums/viewtopic.php?f=11&t=11661	Page 1 of 2

Author:	stringy [ Thu Jan 29, 2009 7:49 pm ]
Post subject:
Roadrunner -you've convinced me! I've ordered a set of brass insert sprockets and screw-in mast Turbo's for an upgrade on my V2 drive. It's a good thing I've got such a comprehensive workshop manual to assist with the conversion! Many Thanks.

Author:	atavuss [ Sun Aug 02, 2009 11:43 am ]
Post subject:	Re: Straightening a Bent Mast on Your Mirage Drive
new here, bought a Pro Angler Friday. took it out Saturday and managed to bend both masts and tear one fin on the first trip! (it was cloudy, the water was choppy and we were running in fast as it started to rain, did not see the boulder right below the water's surface until I was right on top of it). would I be better off taking the masts off to straighten them since they are bent to the side? do they unscrew to remove them? how likely am I to damage them removing them? I thought about laying them on a piece of wood so the entire mast is supported and no pressure is put on the sprockets and pounding them straight.

Author:	Roadrunner [ Sun Aug 02, 2009 3:43 pm ]
Post subject:	Re: Straightening a Bent Mast on Your Mirage Drive
Atavuss, congratulations on your new PA! That's a first class bend in those masts -- excellent work! Yes, the '09 masts are screwed in. Unscrewing them will take quite an effort, as they are Loctited in. You will likely need Vise Grips as well as a big screw driver. Actually, removing the masts doesn't damage the threads -- the damage would come from the vise or hammer (I didn't state that very clearly in the post above -- have now edited it). If you think you can protect the threaded ends while hammering them straight, it should work OK. You don't have much to lose. Worse case, you might have to replace the masts. One way to handle this is to bend them forward in their sprockets first, then unscrew them until the remaining bend points aft. Then bend them forward again. I think they will hold their position to allow you to do this. Or, if you can remove at least some of the bend while the masts are still in their sprockets, it should make it easier to finish with the hammer. If you've got some hardwood for the threaded ends it might work out OK. They don't have to be perfectly straight, but the straighter the better. Let us know how it works out. PS if you unscrew them don't forget to re-Loctite.

Author:	atavuss [ Sun Aug 02, 2009 4:17 pm ]
Post subject:	Re: Straightening a Bent Mast on Your Mirage Drive
those SS sprockets look bombproof! is that a Hobie option?

Author:	mmiller [ Mon Aug 03, 2009 9:24 am ]
Post subject:	Re: Straightening a Bent Mast on Your Mirage Drive
SS Sprockets can be used on current drives. SS sprockets have other issues though. Sloppy mast fit, failed cotter pin keepers, skipping chains, worn bushings (required for SS), sloppy fitting sprocket guards. The new stuff is highly evolved and the latest threaded sprockets are the best choice. Super tough.

Author:	Yakaholic [ Mon Aug 03, 2009 10:10 am ]
Post subject:	Re: Straightening a Bent Mast on Your Mirage Drive
atavuss Be prepared to buy 2 new V2 sprockets & 2 new threaded masts. I have straightened a mast or two in my time but those look pretty bad. Between all the tool marks on the masts and the likelyhood that you have weakend both the masts and the sprockets, well ... you see where I'm going with this. Use what you can salvage as spares and just put on all new parts. My 2cents worth.

Author:	atavuss [ Mon Aug 03, 2009 4:36 pm ]
Post subject:	Re: Straightening a Bent Mast on Your Mirage Drive
Yakaholic wrote: atavuss Be prepared to buy 2 new V2 sprockets & 2 new threaded masts. I have straightened a mast or two in my time but those look pretty bad. Between all the tool marks on the masts and the likelyhood that you have weakend both the masts and the sprockets, well ... you see where I'm going with this. Use what you can salvage as spares and just put on all new parts. My 2cents worth. I managed to remove both masts and straighten them today. I also ordered two new fins and will keep the one good used fin for a spare. no one had any parts in stock so had to order them. will also order an extra complete mast and fin along with a sprocket. parts cost as a FYI: ST Turbo fin 28.00 each ST Turbo fin and mast kit 89.00 I will see if my machinist can make me up a couple of masts as spares.

Author:	Roadrunner [ Mon Aug 03, 2009 6:28 pm ]
Post subject:	Re: Straightening a Bent Mast on Your Mirage Drive
These new sprockets are really tough. Unless they show some problem, I would feel comfortable continuing to use them. If you look at your thread pattern on the masts, you'll see that it is not conventional. Additionally, the SS on these masts is pretty tough (Don't know the # is). So I wouldn't invest too much in machine work -- you could end up with an inferior product with a thread pattern that might be destructive to the threaded brass sprocket inserts. BTW, I have a couple of the old SS sprocket Drives and used them for years. They are very strong but as Matt indicated they have their Achilles heel. They rarely get used these days since the "V2" Drive came out. IMO, Hobie's current ('09) Drive is their best ever without question -- easier to maintain, more reliable and more durable (provided they stay away from those submerged boulders).

Author:	roadog [ Tue Aug 04, 2009 8:32 pm ]
Post subject:	Re: Straightening a Bent Mast on Your Mirage Drive
Beware of bent masts. You can bend them back, but they may fail. I have bent masts back straight, and the masts failed (broke off) a few weeks later. This happened to me twice in July. My policy, because of this is to replace bent masts with new ones. I am big and pedal hard, which helps cause the failure. I use the blue medium locktight, and have never had problem removing mast with a couple of pair of ViceGrips. However, it is a pain in the butt to have to drill and use an easy out, as when the mast breaks off at the hole, which is where they break off. It is alot easier replace the mast before it breaks. It is the pitts to be broken on the lake. The mast are relativly cheap ($14.50?)compared to being broken down on the water. I carry spare masts, as it is easier to replace a mast, then bend it back in the wilds. Plus I know the new mast will get me home. For the Hobie V2 they use 10/32 rod that is threaded with a 5/16 tap. I have ordered some steel rod and am going to make some masts of my own. Has anybody tried titaniaum masts? I have used Gorilla Tape successfully to repair my torn ST Turbo fins. Thanks for all the great info on the blog.

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Author:	atavuss [ Tue Aug 04, 2009 9:00 pm ]
Post subject:	Re: Straightening a Bent Mast on Your Mirage Drive
Roadrunner wrote: These new sprockets are really tough. Unless they show some problem, I would feel comfortable continuing to use them. If you look at your thread pattern on the masts, you'll see that it is not conventional. Additionally, the SS on these masts is pretty tough (Don't know the # is). So I wouldn't invest too much in machine work -- you could end up with an inferior product with a thread pattern that might be destructive to the threaded brass sprocket inserts. BTW, I have a couple of the old SS sprocket Drives and used them for years. They are very strong but as Matt indicated they have their Achilles heel. They rarely get used these days since the "V2" Drive came out. IMO, Hobie's current ('09) Drive is their best ever without question -- easier to maintain, more reliable and more durable (provided they stay away from those submerged boulders). I did notice the threads did not look conventional on the V2 masts........... found a guy on another forum that had 2 sets of ST Turbo fins and masts for 50.00 so I snagged them up. when I looked at them when I got home they are the older style masts with the cut outs for the set screws. oh well, at least I have a good spare set of fins. UPDATE: got the drive put back together with new to me used fins and straightened masts. I trolled for 5.5 miles and did not have any problems. I ordered a set of new fins @ 28.00 each and a set of new masts @ 16.00 each so I have 2 spare sets of fins and masts. will have to put together a tool kit to leave in the PA. we swapped the Turbo fins with the stock fins in a Outback and the turbo fins make the OB go a bit faster. the stock fins from the OB in the PA suck!