Dorsalis Mechanical Failure of Hobie AI Mirage Drive

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Dorsalis Mechanical Failure of Hobie AI Mirage Drive

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Started 6 years ago by Dorsalis
Latest reply from Sirtackalot

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Islander
Member

The point where the attaching bolt/pin passes through results in the arm having less material in that cross section. It wouldn't take a "stress riser" to necessarily cause this damage - the fact that the portion of the arm with the least amount of material in section is also in the area where most of the overall stress occurs is enough for this to happen.

It would be an easy fix, of course. If you have one of the older, 2nd generation drives, you know they had solid crank arms. to my knowledge, none of these have suffered this fate. Although, not as many of those were made and many may no longer be in use, not to mention that not every failure is going to be reported to the public.

A little thicker extrusion might be all it would take to completely eliminate this rare, but obvious situation that can and sometimes does occur in hard use.

Posted 6 years ago #
Karank
Member

Good information and questions and assumptions! It is an obvious weakness of the unit. My bet is that this is a material fatigue probably torsonal that is leading to the failure. When a device like this is refined down to the minimum.... failures occure. The EC is certainly the ulitimate test bed. The Hobie drive has been improved over the years and has become better to the point we expect perfection. They should be very proud of a breakthrough innovation.... but now need to find and fix the problem. Karank

Posted 6 years ago #
Chekika
Member

All good points Karank. It is obviously not a "rare" occurance with as many as 25% of the Islands experiencing this problem. Further, it is possible that the only reason the other boats did not experience this problem is for the reasons Dorsalis suggested: people are not putting enough stress on the drive. Of course, we would prefer a drive which is functional under all situations, not just average use. It is unfortunate when any WT competitor must drop because of a mechanical malfunction. It may be necessary to carry a "2nd" full spare drive, but that is very undesirable when competitors are trying to reduce every pound they can on their boats (well, I know the TIs don't necessary follow that mantra.)

Keith

Posted 6 years ago #
Rodie
Member

I can sympathize with the AI/TI WTers who broke their drives, but keep in mind that maybe 99% of owners never put that kind of stress on the drives. Hobie really can't engineer the drives for the 1%... its cheaper for them to engineer the drives for the 99% and replace the broken ones. Thats fine for them, but leaves ECers in the lurch... no friendly dealership in the 10,000 islands. I think y'alls best solution is to get together and place a bulk order with a small shop who can build a low volume of strengthened parts.

Posted 6 years ago #
Badger
Member

Rodie wrote:

I can sympathize with the AI/TI WTers who broke their drives, but keep in mind that maybe 99% of owners never put that kind of stress on the drives. Hobie really can't engineer the drives for the 1%... its cheaper for them to engineer the drives for the 99% and replace the broken ones. Thats fine for them, but leaves ECers in the lurch... no friendly dealership in the 10,000 islands. I think y'alls best solution is to get together and place a bulk order with a small shop who can build a low volume of strengthened parts.

The ECers are an important test bed and customer base for Hobie. They are prolific posters on social media, and their experiences are broadcast to a wider audience, of whom an important percentage are debating the purchase of competing boats and platforms. I therefore doubt ECers will be ignored.

Hobie would be a poorly managed company if a failure rate of 1 in 100 units was allowed to persist, which then rises to 25% of EC competitors. That is a LOT of replacement, shipping and apologies. This appears to be a product in dire need of redesign and free (or at least really cheap) replacement of suspect units BEFORE they break.

A nicely worded statement from WTers using Hobie AI Mirage Drives to Hobie would be my first step. Alert them to the perceived weakness and allow them to formally respond. If they want goodwill and brand loyalty they'll probably appreciate the opportunity!

Posted 6 years ago #
Islander
Member

While I'd agree that Hobie might not find it cost effective to engineer the drive to handle any and all heavy duty use; that out of the realm of those 99% who are recreational users, if this is something that a very minor change would eliminate entirely, it might well be to their advantage to do it.

In fact, I believe they already have the parts to do it with - the solid crank arms found on the 2nd generation drives could be worth another look. In the quest to shave a quarter or half pound from the drive, the newer hollow crank arms might not have been worth the minor weight savings.

Posted 6 years ago #
Sirtackalot
Member

I talked to Jim from hobie today. They are aware of the issue. Their supplier changed the alloy mixture making it more brittle. Not a design issue, just a supplier issue. I think that's great that we do not have to redesign it after all.........

Posted 6 years ago #
Speck
Member

The newest generation of Mirage Drives is different in quite a few ways from the first ones. They will continue to change. Hobie listens to customers about what breaks and how and they go beyond the promised warranty coverage often.

If you make the drive strong enough, people use it to crack the drive well. Mine cracked and others have too. Hobie replaced the hull.

There was a similar discussion about rudders and sacrificial rudder pintels. Make them strong enough and people will use the rudder to twist off the end of the boat!

Hobie will fix any problem with new cranks, but making such things unbreakable is not always the best answer. Something else is usually breakable, like the hull.

Posted 6 years ago #
Chekika
Member

All good advice. I question whether it is just a batch of alloy--perhaps it is, but there is no analysis to confirm that the breaks are occurring on, say, all drives built in Fall, 2012. Maybe it is, but Hobie has that info.

It is also probably true that if you strengthen the shafts, then the next week link (the hull?) may give--hence, strengthen the hull.

I agree with Badger that the WTers, especially during the EC, are a special group whose influence extends far beyond its members. Just look at the interest in the EC2014 updates on the Hobie forum: >1700 views this week. Those viewers tell others about what is happening with AI/TIs in the EC2014. All those broken shafts caught my attention. I would not want that to happen when I was off Highland Beach, about 35 mi from anywhere, when doing my annual, solo Flamingo-Chokoloskee trip.

I've always pointed out that the EC has frequently been used to display of Hobie's newest AI/TI innovation--the last couple years it has been the jib on Jim Czarnowski's AI. Previously, it was the TI itself piloted by Jim and his charming wife, OceanDiva--what better PR could you ask for?

Therefore, the EC is a great test ground for Hobie. This year the weather has been pretty mild except for the last day or so. It was not a great test of the equipment (mild to moderate winds), and that may be why stress on the on the Mirage drive came to light as competitors pushed their boats.

This group needs to speak out when they find a problem. Hobie will be listening and acting, if they are smart.

Keith

Posted 6 years ago #
Islander
Member

If it is a bad batch of crank arms due to a supplier switch in alloy, then we'd have to assume that all those with broken crank arms bought their boats at roughly the same time; all would have to be roughly the same year model if not even manufactured in roughly the same few months' period.

Beyond that, if a sacrificial parts needs to be introduced, it should be something that doesn't result in a complete failure of the hard item. Rudder pins are easily replaced with spares. Aka bolts, too. But a busted MD crank arm is a little different.

Posted 6 years ago #
Scareman
Member

Perhaps that part has a drawing number and Revision on it. I have never seen Hobie parts to know, but the parts I make for work are all etched with the drawing and rev #.

Posted 6 years ago #
Triman
Member

Triman here. I raced hard and have the blisters, sunburn, photos, and chigger bites to prove it. It is not my fault if my SPOT only worked intermittently. My wife was worried sick and my friends and family were unable to track me. . I arrived at Chokoloskee at 7 pm and left at 1:40 I peddled out against the current and sailed all day in a light north wind which turned SW then SE at Cape Sable. It took me 5 hours to double the last cape against the current in a stiff breeze and I nearly lost my mast. I slept in my survival bag near the entrance to Flamingo after being unable to make headway and being deeply exhausted.and set out again at first light. I left Flamingo at lunchtime along with Dogslife and finished the race just after midnight . I pushed myself and my boat to the limit and finished well. Any insinuation that I did anything else is deeply hurtful.

Posted 6 years ago #
Chekika
Member

Mark, it certainly sounds like you can establish your credentials as a WT EC finisher. Congratulations!

My apologies for doubting it, but it was the strange behavior of the SPOT OK messages. While several solo Tandem Islands made it to Key Largo, you were the first. Quite an accomplishment.

I have posted your statement on the Hobie forum: http://www.hobiecat.com/forums/viewtopic.php?f=72&t=50177&p=230261#p230261

I'm looking forward to meeting you this morning at the WT Ceremonies.

Keith

Posted 6 years ago #
Triman
Member

Thanks for setting the record straight Keith.

Posted 6 years ago #
Dorsalis
Member

Wow, thanks for all of your input here. Trimaran, I'm sorry is somehow, while discussing the Mirage Drive issues, a question was raised with respect to your SPOT integrity. I think we all realize that you not only finishe with honor, but in the frist echelon.

With respect to the comment by Penguinman. If it is true that a "more brittle" crank set batch was used in the last year by Hobie, that would be a concern indeed and might well explain the heartbreak several of us have experienced over begin taken out of the Challenge due to mechanical breakdown, while we still had the will and desire to finish. I look forward to speaking with Jim more about this. He seems to be a very good guy and hopefully will offer more details for us at the finish.

Posted 6 years ago #
PrivateHam
Member

Regarding Triman:

I had the pleasure of meeting Triman several times before, during, and after the race and found him to be a gentleman, an extremely nice person, and a hard competitor to beat. I sailed a TI with my racing partner, Jimbo, and we saw him a couple of times along the way. Specifically, I believe he came up to us early Sunday morning after we both crossed Boca Grande and were looking for a camp site. We definitely saw him when he was leaving Flamingo when we were going in at around 12:45pm on Wednesday.

-Mike

Posted 6 years ago #
Chekika
Member

I spoke with Jim Czarnowski at the WT Ceremonies this morning and he agreed with all the points made regarding the Mirage Drive: (1) change the alloy back to one less brittle, more strong. (2) Increase the amount of material in the area that is breaking--the area where the "length-adjuster pin" passes through the shaft.

He felt it would be a simple matter to strengthen the pedal shafts on new drives--to take place immediately--and work out some recall replacement of pedal shafts in question.

Typical Hobie fix.

Jim also told me, he thought the prototype jib he used in this year's EC was ready for production.

Keith

Posted 6 years ago #
PrivateHam
Member

Jim also told me, he thought the prototype jib he used in this year's EC was ready for production.

If the jib was in production by next year's EC, I wonder if that would be allowed in the TI class since it's a Hobie product manufactured specifically for the TI?

Posted 6 years ago #
Chesapeake
Member

I noticed that the sails (fins) on the broken Mirage drive were not the original ones, but one of the larger sizes. Do they even make the smaller ones? Might they not be better for competition and put less stress on the mechanics? I also agree that the reduced cross section at the hole would be a prime site for failure.

Ron - old AI owner (refers to both me and my AI)

Posted 6 years ago #
Chekika
Member

PrivateHam--I don't know where Jim & Hobie are on a jib for the TI. He said, interestingly, the past 2 yrs using the jib on his AI, the jib broke the boat. He didn't consider that ready for production. This year it did not break the boat--good design. Asked if he had used the jib, he said "Yes." He was especially happy with it coming across the flats 2 days ago. He said he had the main furled and only used the jib; I guess something like a balboa or spinnaker.

If Hobie did come out with a TI jib, but most users did not have one, it seems it would go in the Hobie IM class--that would be fine, I think.

Ron--we have to be realistic here. WT competitors will never go with the smaller size unless there is a rule outlawing the st turbos (never will happen.)

Keith

Posted 6 years ago #
danceswithwaves
Member

Dorsalis,

I understand your disappointment in not being able to finish the EC because of boat failure. I am EXTREMELY disappointed in not being able to continue. Well, I could have attempted to pedal the whole way but, I felt this was not a viable option. Right now the speculation about why my mast step failed ranges from my running into something( didn't happen ) to I was sold an older boat( it's a 2013 model ). I am trying to keep a positive attitude but, it is no solace knowing I was the only TI not to finish. Fluke ? Maybe so. Who wants to be a subject of a fluke ? My need is a boat that is reliable, a boat that will not let me down, no bad batch runs, no defective metallurgy, no inferior parts. Yes, I am willing to pay for that, just not with the currency of a failed EC. Sorry if I sound a bit bitter. I can celebrate other's success. I find nothing to celebrate in my failure. I will be taking the boat back to the dealer tomorrow or the next day. Hopefully, we can sort this out and affect a repair. I have no doubt that it can be fixed. It just could not be done on a beach south of the Chatham River. Royd

Posted 6 years ago #
Etchemin
Member

Dear DanceswithWaves

We took a vote....we all think you should use the Kruger. To my knowledge no Kruger has ever failed structurally. "Just keep it moving" and it will get you there AND back.

Etchemin

Posted 6 years ago #
Dorsalis
Member

Dances and Etchemin

Thanks for your comments. Y'know Royd, I had just passed you not 15 minutes before the fatal "BANG" took place. I remember thinking "poor guy, there but for the grace of God go I....". And in fact, I did. It was such a HUGE disappointment. It is particularly poignant that Hobie acknowleges there was a metallurgy issue. I appreciate very much their willingness to replace the Mirage Drive with a new one but, as you say, I just wish it had not cost the whole Everglades Challenge to get the right part. That was a very high price to pay indeed.

I have read and heard great things about Kruger. But, for this race, the die was cast.

Hope to see you on the water again sometime, Royd. You behaved always as a scholar, a gentleman and the consummate seaman.

Sincerely

Chip Southerland (aka Dorsalis)

Posted 6 years ago #
Chekika
Member

Yes, it is always a wrong when your equipment lets you down. Krugers don't have many working parts, so they seldom break down, but, unless you want to pay about double that of a Hobie AI/TI, you have to PADDLE the EC. Most Hobie owners don't like that option.

2 years ago, BackwaterBob had a similar break to yours Royd. He was at Shark River next to Ponce de Leon Bay. I thought it was a shame, when he was 80% through the EC. He came back this year with the same boat and a new mast step facility and passed with colors. This is what makes WT ECers different from most, they are tough & resilent.

Hobied AI/TIs are very smartly designed production boats. The EC is certainly a major test ground for them. Hobie has consistently cut down their failures.

Best of luck to you fellows in your next EC.

Keith

Posted 6 years ago #
Islander
Member

There is no such thing as a 100% reliable boat, nor much else for that matter. About all you can do is thoroughly check every item, part and piece, modify/improve anything you suspect or find deficient to the extent your personal expertise will allow, and give it a go.

At some level of competition, few competitors use standard, off the shelf production equipment. That is the realm of custom produced gear which is designed, built and tested for specific use. For the Hobie Islands to do this well in an event they are not necessarily designed for is testament to just how good they are for a production piece. And to their credit, they keep improving things based on user experiences and reports.

Posted 6 years ago #
danceswithwaves
Member

Stan, Chip and Ken,

Stan, in the 2013EC, I never even put on my spray skirt. I hear what you are saying. Chip, we will prevail. Thanks for your kind words. Ken, I do not mind being tough and resilient... I want the same from my boat. I had 4 great days of sailing, I needed a few more. So, do I do like Backwaterbob and get a new assembly and try again? I, at no time in the previous 11 months, stressed that sail rig. I hit nothing. I did not abuse the boat or rig. Ken, are you suggesting that the boat is still in the design phase and the bugs are still being worked out ? Really ? When will the excuses stop and the reputation for reliability begin ? Sorry, I'm feeling a bit sensitive at the moment. Royd

Posted 6 years ago #
DogPaddler
Member

Dorsalis & danceswithwaves,

Sorry you couldn't finish the EC after all your effort and planning.

Reading about rudder, mast step, and pedal drives on the Hobie forum over the years reminds me of the problems I encountered with windsurfing and it's evolution. Broken ( fins, fin boxes, universals, mast tracks, bases, mast extensions, masts, boom parts, poor sail reinforcements, boards ). Basically everything broke for years mostly due to UNDER ENGINEERING and lack of THOROUGH TESTING.

We the consumers were doing most of the field testing until improved equipment design and manufacturing technology finally caught up and produced very reliable equipment.

You're fortunate that Hobie is good about replacements but that doesn't make you feel better about having to drop out. I remember how I felt when the head of my sail ripped out at the beginning of a long distance regatta race. DNF. I prefer equipment that is OVER ENGINEERED at the cost of a little more weight. I hope Hobie takes that approach with future improvements.

Brad

Posted 6 years ago #
Chekika
Member

Royd, I have made your same complaint ("why are we beta testers?") 5-6 years ago when I first bought my AI. I think there was some truth to it then.  Today, I think the AI is a mature product. Interestingly, I don't think any of the AIs in this year's race experience either the drive failure or the mast step failure.   To my knowledge, the AIs generally have not had mast step breakage of this type. The breakage seems to be occurring in the Tandems with their larger sail. Also, remember, there were about twice as many tandems, and half of those were 2-person teams (twice the drives) as AIs. Therefore, there was much more "chance" for things to break on Tandems.

I do not make excuses for Hobie. Nor am I a "The AI/TI is perfect" type owner. I think if a product is on the market it ought to work as advertised. Having said that, I have to go back to the old adage: "the EC is a pressure cooker for the Islands." I think it is a fact that the more moving parts you have the greater chance of one of those parts breaking—kind of a Murphy Law.

I also think that more Mirage Drive shafts were broken this year because winds were relatively light at times. These conditions caused more dependence on the Mirage Drive and more stress on the Mirage Drive.

Regarding the mast step breaking, that may be due to an earlier design in the Tandems which, I believe, has been replaced by Hobie. There have been discussions on the Hobie forum of the problem, and Hobie's free fix. Even reliable-line car makers make recalls from time to time. I guess if you really don't want anything to break, the Kruger* might be your best choice. However, we don’t own Krugers. Therefore, I believe in holding Hobie's feet to the fire. These boats can be more reliable.  Given how AI/TIs are used around the world—frequently in extreme conditions—Hobie should design them for that use. It may cost more.

The mast step breaking, old design, seemed to be a matter of design and fatigue due to use. It has been redesigned, but I don't know when all the TIs with the old design were off the dealer shelves. Of course, if a person bought a used boat, they might encounter the problem.

Keith

_______________

*When Krugers are outfitted with a Balogh sail and outriggers, there are failures also. I only noticed one such system at the start this year. Given the price point, I believe people are buying Hobie AI/TI rather than Kruger/Balogh systems.

Posted 6 years ago #
Etchemin
Member

I was not addressing the Kruger outfitted with a balogh or any other sailing system. I was addressing the reliability of a Kruger. They dont seldom fail...they never fail...hence the price point. I have found many times (not all the time) when equipment fails it is being used for purposes not designed for the market that is using it. The market for a Kruger is expedition use not weekend excursions. Maybe if the AI was designed for true expedition use then the price point would approach the Kruger. Just some random thoughts not meant to disparage the choice of boats. I just couldnt resist the comment after seeing 51 comments devoted to this thread.

Etchemin

Posted 6 years ago #
danceswithwaves
Member

Ken/Stan,

My recent EC experience and subsequent comments on the subject are not meant to disparage any one boat design. We, all, will have preferences, of course. The Watertribe concept was established to incorporate the development of small boats for expedition use. To that end, many of us search for the perfect boat. A boat that fits our individual needs. Some of us are pure paddlers, some pure sailors, some somewhere in between. We, as individual competitors, must balance all that and come up with a boat choice. Personally( and, at the risk of bitter failure occasionally), I rather enjoy trying out different boats( much to the chagrin, I'm sure, of my wife when she gazes out over our boat littered yard.) I've always held that it mattered not what boat you used to go a-seafaring, the important thing was that you were out on the water. To paraphrase, rather badly, Kenneth Grahame, there is simply nothing so fine as simply messin' about in boats... messin' about in boats. I and many others, I'm sure, ascribe to this philosophy. So, my quest for the perfect boat will continue. The lure of the sea and the vessels we use to venture out on it are obsessions that, as far as obsessions go, are not all that bad. Royd

Posted 6 years ago #

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