Keep breaking pedal cranks!

So I bought a new outback this year and I have broken two pedal cranks in the last month! Both of them right at the hole. I was surf launching and it was pretty big today. I had to race to get over an overhead set and just before I reached the wave, snap! Put me in a really Nast spot. Right in the impact zone on a big day with a broken crank. This is the second time this has happened to me in the last month! What gives??

The first time I didn't bother with warranty. I fish everyday and I live in Costa Rica so it takes long enough to get parts here without fooling with a warranty claim, but man, I can't buy a 40 dollar piece of steel every month! Please advise me on what I should do. Thanks.

Lance

PS. Yes, I am running the turbo fins but if those put too much pressure on the cranks then why do they even sell them?

You could always try fitting a set of the old solid cranks with a pair of aftermarket bike pedals. They're still available and are apparently bullet proof.

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Simon

A kayaker in the Pacific Northwest is manufacturing solid pedal arms. Check out http://www.northwestkayakanglers.com/in ... ic=13295.0 . It may be too late to get in on the lower price for kayakers who paid up front for arms manufactured in the initial run, but ask him when he's going to order the next run.

As you can see from that thread, there are a lot of Hobie owners who, like you, have broken multiple pedal arms. This is quite disappointing, and an indication that the design and/or materials of the pedal arms is inadequate and defective. Pedal arms are a central part of the Mirage Drive system, and they should never break. The crank arms on bicycles never break. Hobie should be able to design and manufacture pedal arms which don't break. It should not be necessary to go to an outside manufacturer in order to get pedal arms which won't break.

In any mechanism with moving parts, sooner or later, something is going to wear out and/or break. Hobie engineers probably went a bit to far in trying to shave weight from kayaks that get heavier each model year. I would think they are aware of this crank arm issue and will come out with stronger arms that could be retrofitted to current Mirage drives. Hobie has always been pretty good about taking care of manufacturing issues.

Marine hardware, especially hardware that is exposed to the ocean environment is not usually made from aluminum. Aluminum, even galvanized aluminum will oxidize, weaken and eventually fail. There is also the issue of galvanic interaction, especially between different materials like steel and aluminum or carbon and aluminum. This galvanic reaction increases exponentially in a salt water environment.

I own a paddle kayak but am an avid cyclist who has owned many bicycles and I can tell you that crank arms and pedal spindles on bicycles do break, along with every and any other part of the bike. Perhaps the Hobie engineers designed the crank arms with a little "give" in them. A system always fails at the weakest point. The whole drive system is attached to a piece of plastic, if all the Mirage drive parts were made from metal or inflexible composite, a strong peddler may rip the drive right out of the kayak. Even though you see a number of complaints about broken crank arms on kayak forums, as you would expect complaints on any forum, it is pretty likely that the overwhelming majority of Hobie Mirage kayaks don't have any problems with the crank arms, only the advanced, stronger kayakers who are peddling kayaks coming pretty close to the weight limit of the boat in demanding conditions that are having the problems.

In a perfect world, the crank arms might be made from carbon fiber with stainless steel inserts, much like modern bicycle cranks. They would be stronger and lighter than aluminum and a degree of flex could be built into the layup to take some stress out of the mechanism without sacrificing stiffness. The only problem is that they would cost five to ten times more than crank arms made of any other material. There is a saying in the bike business; "Strong, light, cheap; pick two", that would apply here.

If it's moving, it can break. Never say never.

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Waterman at Work - Kayak Fishing Photos, Video,Kayak Rigging - Blog

pmmpete :
Agreed, though I have 2012 vintage pedals on my TI (before re-design I assume), and I have never had any problems, it appears the vintage 2013-2014 pedals have more problems. I looked at couple 2013/2014 pedals that had broken at a race at one of the Hobie Island club events, the design of the pedals was definitely different from the pedals on my 2012 TI and all the TI's and mirage kayaks I owned in the past.
Actually they looked like they might have been die-cast or MIM vs extruded aluminum, everyone knows die cast isn't nearly as strong as extruded aluminum, and fatigues much quicker because the molecules aren't aligned like they would be in an extruder. ( Though I didn't look at them that closely, so I have no idea whats really going on, but the fractures themselves looked like a sand finish, which is typically of a break on a die cast part vs an extruded part, breaks on extruded parts typically look more like pulled taffy. Though I didn't dig any deeper into the problem because I don't have that style of drives so it's just not my problem ( LOL).
There are two different problems out there with the mirage drive arms, the problem with the drives breaking up at the top I have no solution for (not my problem LOL), but the other problem with breakage down at the 1/4" adjustment pin halfway down the shaft, I outlined a possible cheap fix (for a couple bucks) a while ago ( do a search on this forum for past postings on the subject).
A guy on the forum who had broken quite a large pile of the drive shafts, and I was just trying to help him out personally, I wasn't suggesting any type of manufacturing fix for Hobie (that's their problem).
What I suggested is if he gets a new arm, before installing shove some paper wadding in about an inch above the 1/4 inch adjusting hole halfway up the shaft (from the underside of course). Then put a 1/4" dowel pin into the hole that has been greased up (or I suppose you could use the pin that is supposed to go in there, just make sure you grease it up so the epoxy doesn't stick to it). Then just drop a couple drill bits (maybe 3/32 dia) in so they fall along each side of the pin. Then just pour epoxy or polyester resin into the tube so it is about an inch or two above the side pin hole (shouldn't add more than a couple ounces to the weight of the drive). This encases the drill bits in epoxy and provides the necessary strength needed to prevent the aluminum from fatiguing at the high stress point around the hole. Shouldn't take more the 20 minutes to do and shouldn't cost more than a buck or two in materials (most of us have old drill bits and epoxy laying around our garages anyway, if so the fix is free). Drill bits are typically cobalt steel so they don't rust anyway, besides they are completely encased in the epoxy anyway so water would never get to them. If you wanted to go overboard you can always put 4 drill bits in there (one in each corner).
The paper wadding is to prevent the epoxy from going past the area that you need it of course, you only need the epoxy 1-2 inches above and below the 1/4 inch hole. When all done just pound the dowel pin out and assemble the drive like normal. It will never break again (strengthwise probably stronger than the solid pedal (with 4 drill bits) believe it or not).
I'm sure Hobie will get the design fixed eventually and come out with a better pedal shaft design, but that usually lags a yr or two behind reality, so this fix should hold you over in the mean time. Simple to do, and it won't cost you a fortune buying the solid shafts, then having to jerry rig regular bike pedals to your mirage drive. It's all your choice of course.
I hate to spoil that one guys cash cow ( LOL)
Hope this helps
Bob

Maybe more like going full throttle and full breaks on your car... tires wouldn't last and the drive system would get damaged, but we did have some issues last year. We had a metal / hardness issue it seems and should be well beyond that now. 100% testing has been going on since early last winter to weed out the defects. Cranks are MUCH stronger now.

Fyi... Solid ones from years ago... are no longer available.

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

Thanks for the info mmiller. I'm a cruiser not a racer. I typically troll for 4-6 hours so I'm at a pretty moderate pace. There are a few moments during surf launches like yesterday where I have to pedal harder and that's how I broke both pedal cranks. So for the car analogy I reckon it would be more like flooring it to pass on very rare occasions.

Anyway, I contacted hobie and the vendor today and a quick and fair resolution was reached. Thank you all very much. I have always been very impressed with hobies customer service!

Are the arms of the drive striking the boat front or back when you pedal? If so this could be the problem. The arms move 12 inches at a stroke regardless of the setting and of this 12 inches of movement the last 2 inches represents wasted effort as the fins are nearly parallel to the bottom of the boat and not moving much water. I get more sustained speed by using a shorter stroke and using the power portion a greater percentage of the time overall.

Broke another pedal today in the swell. This time the right side. I've broken both left and right and the replacements. I've done it in different situations. I am a light guy and pedal modestly. I'm getting tired of these poor designed pedal arms from last year. I was cussing pretty good today, rolled the yak and all, lost the broken arm with all parts attached to it. This is a poor design issue, I sure hope Hobie has fixed this issue. My mirage pedals are less than a year old. Being here in Costa Rica is a pain in the *** to get things. Let alone the slow service from my dealer. Going to have to try someone else to put in the claim.

As far as you folks who will try to come up with reasons why this is happening, forget it, it's just normal pedal stroking, no bottom slapping, no happy feet, etc. Man am I pis***.

Also I would like to note, my replacement shafts we're sent out on March 13, 2014, so I hope these are not the new improved crank arms of which I just snapped the right side one? Had about 50 hours on this shaft before it snapped.

Sorry for the vent. I know Hobie will make me whole, always have. Glad to hear that the new pedal arms have been improved and will be looking forward to a new set.

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Mark
Tandem Island- 2013
2 - Sports - 2014

March pedal shafts were older versions. Current replacements would be new.

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

I have been cycling for more than 40 years and worked in a bike shop while going to college. I only know of one pedal that broke that was from a quality manufacturer. Some of the early aluminum cranks would break from a certain French manufacturer in the 1970's, but those problems are not seen with current products being manufactured in Japan, China, or Taiwan.

We manufacture parts from aluminum and there are different grades with different performance characteristics including breaking strength. We use aluminum grade ANSI 6061 for most parts but for ones that are subject to strong stress we will use ANSI 5083-H32. This is really not rocket science and the stronger aluminum is more expensive to buy but not more expensive to machine (as with stainless steel).

There should be the expectation with fishing kayaks that most users will be adults and the pedal arms should be designed to handle the load or a clutch mechanism or a shear pin used so that something other than the arm breaks with load.

The idea that a strong arm would cost 10x as much to manufacture is rubbish. It is only the materials that will add to the cost and if material costs 2x that does not result in a finished part that costs 2x. There is a multiplier with a manufactured part that usually is around 7 to 1. If a part costs $1 more to make that is going to translate into a retail selling price that is $7 greater.

Along these lines if the use of a stronger aluminum was used it might result in adding $70 to the price for a kayak and Hobie seems intent on protecting a price point unless it is with the addition of something that has marketing appeal like the new seats on the Revo and Outback boats for 2015.

Bottom line, if Hobie cared about the problem with the cranks breaking they would change the design or the materials used. Clearly it is a very low priority item if it is even on the list for the product development people. That is one of the problems when there is a lack of competition. Changes to new models is more a matter of cosmetics than functionality or durability or performance.

One option for users is to remove the turbo fins and go back to the standard ones and to use 3/4 pedal strokes to minimize the loads on the cranks. The other is to carry a spare Mirage drive in the bow compartment of the boat.

There is a misunderstanding of the problem and Hobie's solutions.

We believe that pedal cranks are no longer an issue. We addressed the problem aggressively last spring.

We had few issues with cranks failing until 2013 when there was a spike in claims. The largest number of failures is from aggressive pedaling. Add inconsistencies in production = more failures. This identified a supplier issue... not a design defect. Of course, some would say design, because we could have a 100% unbreakable crank by over building them. That would add weight and cost, so not the solution we feel is the right one.

Primarily the material and hardness process were in question. There were inconsistencies in the hardness. We started 100% hardness testing on received product and then, analysis of materials and hardness issues from the supplier. In addition, we made some other changes to increase the strength factor.

Understand that there will continue to be some failure of older product. There are a lot of MirageDrives in use.

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

I have a 2013 Revolution. I don't like the risk created by fishing far from shore while using crank arms which appear to have a high risk of breaking, so I invested in a pair of the solid crank arms produced by the Northwest Kayak Anglers member mentioned above. I wish that Hobie had offered to replace the defective crank arms, so I didn't need to incur the expense of buying solid arms.

Based on what mmiller stated about 100% hardness testing and design modifications, if I have an older mirage drive that needs a new crank, how do I know if I am getting old stock or new stock when ordering a replacement part from a dealer that may have the older untested cranks in stock? Did Hobie recall all those non tested older cranks already out in the parts stream? Am I also safe in assuming that all the cranks placed in the new Hobie Miragedrive GTs have been tested for hardness under Hobie's ongoing quality assurance program? I own an original miragedrive with comfort fins from a 2011 Outback and the crank arms have a glossy black finish and I just purchased a new 2015 Mirage drive GT with ST fins and noticed that the crank arms have a brushed or burnished finish is there some significance to this new appearance in finish as it relates to the aluminum manufacturing process? I think it would be safe to say that all Hobie Miragedrive kayak owners consider this a very important issue with regards our safety.

I was at the Hobie dealer the other day and got a chance to look closely at the new glide mirage drives and their construction. I have to admit I am very impressed with the design (I'm a product designer). I'm a long time mirage drive user (since 2007) and have never had a lick of problems with any mirage drives even though I pedal my current 2012 TI an average of 10-15 miles per week all year round. Just observing how many Hobie kayaks there are out there that operate with no issues I have no concerns with the new mirage drives. I understand they did have a small materials problem sometime in 2013 for a short period of time, I would be very surprised if there are any bad ones still out there, even if some creep up, everything should be covered under Hobies warranty. I suspect it was a very small number of defective drive, and have no concerns about buying the new drives when the time comes.
Bob