Flippers, Pedal Arms: Overuse Breakage?

Guy that let me try his 16' Revolution today turned out to be quite a heavy user: he has 3 Mirage-drive Hobies... different lengths for different applications, and has been doing this for several years now.

He observed that, as the season wears on, flippers and pedal arms start to break. He broke a flipper just a few days ago.

He attributes this to his getting in better-and-better condition as the season progresses until, finally, he is putting out enough horsepower to break these parts.

This guy looks strong to me - especially in the legs and, watching him motor around the lake, I come away thinking he is in pretty good shape.

So, bottom line: is this an anomaly, or do mere humans experience fin and pedal arm breakage when they really push the Mirage Drive?

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2015 AI in "Dune" - "The Grey Pig"
2017 Trailex 450 Trailer
Pre-September 2015 cradles
(anybody want to buy a slightly-used AI SpinKit?)
eMail: [email protected]

Last year the 300-mile WaterTribe Everglades Challenge was cancelled at the end of the first day; however, the previous year there were numerous (7-10) reports of broken mirage drive shafts on TIs and maybe an AI or 2. If the wind is not blowing, the competitors clearly stress their mirage drives.

I have not known anyone to break a drive shaft on a "leisure" camping trip.

Keith

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2015 AI 2, 2014 Tandem

"Any intelligent fool can make things bigger and more complex ... It takes a touch of genius and a lot of courage to move in the opposite direction." A. Einstein

"Less is more" Anon

Pedal shaft breakage was corrected (0% failure that I am aware of now) as of a year or two ago. Lots of discussion on it here. We had some metal alloy and hardness inconsistencies for a period of production. We corrected that and then added some thickness to the cranks... Not an issue for a long time now.

Fins failing? That is rare.

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

We have chocolate milk in our lakes and rivers, usually can't see more than a couple inches below the surface. So I have run into many shallow areas and even a few submerged trees, once while moving at a pretty good clip, and have never had anything break on a Mirage drive. The one time I was moving fast, the tree grabbed the fins (or maybe the other way around) bringing me to a sudden full stop. All that happened was the front fin was bent back so far it overlapped the rear one. I had to bend it back straight enough not to overlap while sitting on the water - quite a feat, but I managed it - then just plugged it back in and limped back to shore. I was still able to use the drive, just the blade shafts were angled to the sides a bit so I couldn't get a full stroke. I straightened everything out once I was back home.

Considering the forces the blades and drive must experience when hitting shallows or submerged stuff, I can't see "mere humans" pedaling causing a breakage unless they're doing something like "hitting the stops" - hammering the pedals against the front or back end-of-travel. If the pedals are adjusted properly you shouldn't hit either extreme at all.

Though I did wonder about my nephews the other day. Whether I'm pedaling easy or hard, I tend to be very smooth and even over the entire stroke, same as I do when riding my bicycle long distances. My nephews, though, felt more like someone standing on the pedals and sprinting up a hill! Very short, sharp bursts of power at the start of each stroke. I suppose that sort of pedaling could fatigue things more quickly.