A heavy duty Mirage Drive?

Hi all,

I have had a Hobie PA12 since 2015, and it has been used intensively. Being keen on fishing and also doing exercise, it is a perfect tool for my needs.....mostly!

In the past 2 years I have changed 6 idler cables and chain assy's, I have have seen cracks in the root of 4 crank shafts, and I have recently broken off one pedal.

Do I handle things wrong? Definitely not! I am machine engineer from education, and have 56 years of life experience with bikes, boats and cars (OK, the first 5-6 years maybe not that much). I know how to tighten a cable until it is tight enough, and the bearings are not squeezed. I do check the cable tension every time I go sailing, and I do rinse and grease the chain. The drive is rinsed with freshwater after each saltwater trip, and I regularly coat everything with Prolan (lanoline) grease.

One year ago, I changed almost all wear parts of my drive. Two new pedal cranks, two new sprockets, two drums, a new drum shaft and all the bearing pins to go with it. Almost a new drive. I was trying to eliminate worn out things could influence wear and breakdown on other parts by doing this change in one cycle.

This "new drive" has not saved me from breakdowns though. 2 chain assemblies, one idler cable and two crank shafts have been damaged. And the broken off pedal to top it all.

You all know how annoying it is to have a breakdown on a trip. I have learned from experience, that the paddle needs to be along with me. 3-4 km of paddling is pretty hard though. Especially in a PA12 loaded with equipment. It adds up on the exercise off course.

I really like the sailing experience of the Hobie Kayak, and I wouldn't hesitate to recommend this kayak to others, if it weren't for these breakdowns. As engineer, I cant stop playing with upgrades for the kayak, but until now, I haven't found good enough solutions for the chain drives. I have repaired one with silver soldering a cable into a grub screw, and it worked - until the chain broke.

If the reason for my misery is too hard pedaling, I might consider competing in sports again. But I stopped competing in spearfishing 21 years ago, and my lungs are definitely not up for a come back. I'm not older than Mike Tyson, but I don't think he should consider a come back either.

Any advices from Hobie or from fellow kayakers?

I have started to make my own DIY heavy duty solutions. Here's the idler cable in a manageable way:

The metric dimensions are:
Brass pipe 5-8mm
Grub screw 6x35mm
Dyneema rope 4mm







I have earlier tested a simple solution with 3 kevlar strings, which lasted for quite a long time. The 4mm Dyneema rope is an obvious upgrade. It could be covered with shrink tube, but I think it will last without, because it is enough overdimensioned to handle the wear.

Crimping is absolutely not the best solution for connecting to Dyneema. This one didn't last very long either. About three hours of hard pedaling on a icy river.

Theoretically you should use a splice, but it takes a lot of space in this area. I am testing other methods. Will be back with results.

I used to have very strong legs pre-pandemic, and would damage my drive well by excess forward thrust against a high drag kayak. Eventually I realized this came from me occasionally pedaling like a beserker when slightly faster boats passed me along a canal. Even tho they should be faster, I felt some triumph by briefly catching up.

So I stopped this sprinting, and my 5 year old drive stays pretty much like new except for a bent mast. Also I resist tightening the chain too often, just like I fight my tendency to overtighten screws, etc. I think things generally like to run looser than spec, and are intended to be so during long gaps between service.

Hi Yaw_string,

I agree with you that it is pedal force driving the wires to snap. It can be momentary extreme high force, but it can also be longtime medium to high force. The braking strength of the wire is way higher than we can accomplish momentarily, but there's the fatigue strength, that you will overcome over time. If you pedal low force, that will take you almost forever, but medium to high forces will wear out the wire connection fast. I have had my idler cables for averagely 6 month, so that means that I am adding a medium to high force on them.

Nothing in the descriptions from Hobie says, that you cannot pedal with high force, and if you want some gain from exercise, you need a certain level of effect (force/time) to get it. I am an middle aged man fighting with the diseases of an average man this age. I simply need to exercise to keep alive ;-/ What is better than sailing on your favorite fishing water, while obtaining the drug that keeps you alive

I would very much like to help Hobie make a heavy duty drive, or at least make one for myself. That way I am saved from a lot of killing (boring) hours in the gym.

You seem like a very focused guy, and your thorough write-ups in this thread I appreciate reading. Based on what you are saying, though, you seem like you might be the kinda guy that's sorta hard on things. You said, "Nothing in the descriptions from Hobie says, that you cannot pedal with high force..." Nothing in my car manuals have ever said I can't drive with the accelerator always being punched from a dead stop, but that is rough treatment and I would argue that if done regularly would be deemed "Unreasonable" wear and tear. Nothing in the description from Hobie says, "Indestructible" either.

I like your idea that maybe Hobie consider a "Pro" version of their Mirage Drive that is meant to be used hard and often. It would certainly appeal to professional anglers.

You seem like a very focused guy, and your thorough write-ups in this thread I appreciate reading. Based on what you are saying, though, you seem like you might be the kinda guy that's sorta hard on things. You said, "Nothing in the descriptions from Hobie says, that you cannot pedal with high force..." Nothing in my car manuals have ever said I can't drive with the accelerator always being punched from a dead stop, but that is rough treatment and I would argue that if done regularly would be deemed "Unreasonable" wear and tear. Nothing in the description from Hobie says, "Indestructible" either.

I like your idea that maybe Hobie consider a "Pro" version of their Mirage Drive that is meant to be used hard and often. It would certainly appeal to professional anglers.[/quote]

Hi Puto,

I am focused, but I am not a pro sportsman. If I was, the Mirage drive wouldn't last many days.

When I buy a bicycle, It doesn't say "not for athletes" or "not for heavy cycling". Off course you can judge from the appearance and the price, if it's meant for race or relaxed touring.

But if I buy a Jaguar or a Rolls Royce, I expect it can do everything. I also pay the price for it. Exactly like the Hobie Kayak. I expect that it can keep up with some heavy pedaling without going into the extremes. And I pay for it!

I don't think I am unreasonable. And I could point at some weak points, that should have been fixed (years ago). I must say, I am kind of leaning at the thought, that these weak points have been made (or kept) to keep up spare parts sales.... As an engineer, I would actually call them blunders or deliberate weaknesses. And that is not what I expected from a top class brand. Maybe I am wrong.....

I've owned my 2014 Revolution since September 2013, and I've used it for a huge number of days since then. In that time, the only part which broke was a single cable. Early in that time, a lot of Hobie owners were breaking their pedal arms, so I bought a pair of solid aluminum pedal arms which a kayaker from the Pacific Northwest manufactured, which may be why I never had any problems with my pedal arms. My Revolution in general, and my Mirage Drive in particular, have been very reliable. Fisherteknik must be way stronger and more aggressive than I am to have broken so many parts on his Mirage Drive.

The pedal arm was exactly one of the things I was aiming at, when I said that there are obvious engineering blunders or built in aging points. The hole for the bolt in the end is way too close to the end, and there is actually space for leaving more material, when machining the chamfer there. That could have been corrected years ago, with only few administrative costs. The use of aluminum and stainless in stressed areas is also critical. There will be some critical corrosion on the aluminum from electrolysis in saltwater.

I agree I am putting an effort in reaching the fishing spots in a limited time, but if that's critical, why don't they sell the kayak equipped with an electric engine? I guess for many people transportation is purely a matter of activating the throttle....!

I absolutely disagree with the people, who claim that I am abusing the Mirage Drive. Like running a car in the highest possible revolutions all the time. In many cars there's a red field on the rev. counter, signaling that this is critical area. Even your driving teacher may have pointed out, that this is abusing the engine.

It's definitely not abusive towards your body to exercise frequently, and nobody have claimed that the Mirage Drive is too fragile for the purpose. In fact some of the commercials even show people kind of exercising and one is showing a man competing against a 2 person conventional kayak in a towing competition. In the commercials there are no warnings against using the Mirage Drive for cardio exercise, and in my opinion it would also be stupid to exclude these healthy people from experiencing the Hobie kayaking. I would say there's a huge potential in that area, as you are using bigger muscles than people in conventional kayaks. Thereof better possibilities for cardio exercise. Hands free for fishing is just an extra benefit.

I don't think the standard Mirage Drive (from 2015) is rubbish. Far from. It's just lacking some of the longevity you would expect, as a person keen on exercising. It wouldn't require a total redesign to make it fit for the purpose, but unfortunately it seems Hobie is working other directions. There's a sharp focus on more advanced gadgets. That's a shame!

Fischerteknik,

Thank you for your clarifying posts. I apologize for assuming you might be extraordinarily rough on equipment, but based on your followups, it's clear you are an infrequent yet heavy user but not an abuser of equipment. I enjoy reading your technical critiques, especially due to your engineering knowledge. These are all things I would never have considered. I hope it results in stronger, longer-lasting (aka "Better") equipment and therefor experiences.

Puto

Been years since I posted here, but want to toss in my "2 cents".

Too much pitch is a bad deal. I have run my original drives (from 2003) and never broken a cable. I use the Turbo Fins and I add a small link (at the tension adjustor) to allow them to kick out sufficiently during the pedal stroke. This means the energy applied at the pedals is not wasted on pushing water sideways....against each other, and thus drives the boat forward.

Think about where the water is driven when you push those pedals; sideways....or back?

If those fins don't flop considerably, when they change direction, you are trying to run about the same blade pitch as a Mercruiser outdrive with a 350 V8 Chevy! That's actually just a simile, but I think you understand my point.

I have the last (top) thread of the tension screw crimped, so I can run minimum tension without the blade coming off.

My drives are very easy to pedal, and other Hobie owners who have tried my drive are surprised at the improved speed for less energy.

One more little "ponder point": You've all seen a powerboat running across the water at high speed while leaning strongly to one side. That is a common problem when you have plenty of power, heavy boat, and too much pitch on the blades. The prop rotation is trying to "climb" out of the water, instead of driving the boat forward.

Pushing water sideways with your blades is a dead end.

picture please
I have turbo fins on my 2017 Adventure Island that i use a lot without sail but with ama's so if I go out on Caloosahatchie river it's stable.
It goes pretty fast it seems, but is 2-3 pretty fast?

If you look at the pitch angle of a propeller, you will notice that it declines over the radius. A fast moving blade or wing will need to have a lower pitch than a slow moving blade. Same for the fins on the Mirage Drive: If you plan to use slow pedal strokes and thereof low power, it has to have a high pitch or low tension in the tightening screw. It's just like a gear, and this is the low gear.

On the other hand, if you plan to use high power with high speed strokes, you need a high tension on the back of the fin. If the tension is too low, you have no chance of transporting the high power into high speed.

Speed in a river is off course quite relative, as there is up- and downstream speed. I have measured my speeds in a calm lake with no wind, and will often be able to run close to 4 knots (with high tension on the fin screw). A half hour exercise for me can be held with max. 4.2 knots. Then I'm totally done.

I am not a speed maniac, and I have a chronical lung disease, which keeps me from doing other kinds of exercise. I have earlier been cycling, running and swimming (until 15 years ago). For some reason medium speed pedaling is doable for me, while the other kinds of exercise is not. That's why I would do many things to be able to continue pedaling without regular break downs.