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Another Chop Mod...Longer Cranks
http://www.hobie.com/au/en/forums/viewtopic.php?f=11&t=13835
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Author:  JeffreyET [ Tue Aug 18, 2009 1:11 pm ]
Post subject:  Another Chop Mod...Longer Cranks

I've seen all kinds of creative solutions to personal needs on this forum. Here is one of mine.
Being 6'2" in a 2006 Sport, I always desired having a longer pedal throw without hitting the hull, as seems common judging by other posts. So I decided to try making new cranks with added length of 2 1/2 inches.
I bought solid aluminum squarestock from one of the several online sources, less than $15 for 36" (I measured the original hollow cranks, forgot whether they are 3/4" or 11/16"). There were 4 holes to bore: One for the fulcrum, one for the adjustment pin, one for a machine screw at the top to secure the pedal shaft, and one for the pedal shaft. This one was stepped to match the shaft profile.
So with a drill press and vise, the right size bits and bores, and a tap I was able to actually improve on the original crank! A smashing success.
The increase in throw length is noticable but not as great as I had hoped. However I also gained more pedaling leverage, and now I can alternate 2 pin settings instead of just one as needed.
You may also notice I have replaced the plastic pedals with custom ones also made in my shop, out of Trex cutoffs. I like them because they are reversible, and with wet feet in warm weather, they are very comfortable.

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Author:  KayakingBob [ Tue Aug 18, 2009 2:49 pm ]
Post subject:  Re: Another Chop Mod...Longer Cranks

Nicely done! :)

Author:  Yakaholic [ Tue Aug 18, 2009 7:25 pm ]
Post subject:  Re: Another Chop Mod...Longer Cranks

Jeffrey

Outstanding work!

Pedaling would be easier because you have more leverage albeit with a longer stroke.
With those longer arms one could increase the size of the flippers for a real increase in power. You may have just developed a "racing" version of the mirage drive :lol:

Wait till Roadrunner sees those. :shock:

Please update us as you continue to use them.

Nice touch on the custom foot pedals too.

Yakaholic

Author:  Roadrunner [ Tue Aug 18, 2009 8:46 pm ]
Post subject:  Re: Another Chop Mod...Longer Cranks

Very nice project! That's a great way to stretch out a Sport. Maybe Hobie would consider making some "Super Turbofins" to match! :wink:

Author:  JeffreyET [ Wed Aug 19, 2009 6:19 am ]
Post subject:  Re: Another Chop Mod...Longer Cranks

Thanks for the kudos!
The increased stroke is not a bad thing, quite the contrary, it was just what I was after. And I'm finding the drive has more sensitivity when I flutter it.
I'm using ST fins, wondering if I should have gone all the way to Turbos. I thought about it - but being a DIYer (as well as a skinflint) I shopped around for SS rounds to make my own masts... I would have notched a more precise angled keyway or crater for the setscrew. But alas, Hobie uses a very odd size just a bit larger than 1/4" so I just went with the ST's for me & my wife - she was worried about keeping up with me anyway :lol: .

BTW I will take orders from interested mirage yakkers, just shoot an email.

Author:  PeteCress [ Tue Aug 25, 2015 7:20 pm ]
Post subject:  Re: Another Chop Mod...Longer Cranks

OK, it's six years later....

How did the whole system hold up?

Flipper breakage?

6'5", thinking about doing or buying the same thing...

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