Stainless Mirage drive pedal cranks.

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Yakass
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Re: Stainless Mirage drive pedal cranks.

Post by Yakass »

Yep Shane, someone here made the same suggestion. But I have always preferred thru-bolting for completely unrelated reasons (this inspired me to go back to it) and the wingnut gives me the ability to adjust if required. Best of both worlds. I always carry a Leatherman tool on the water, so I can grip the hex head with that.
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Yakass
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Re: Stainless Mirage drive pedal cranks.

Post by Yakass »

maverick wrote:The yak range is not designed for flow fins, so there could be warranty issues. The steel cranks shouldn't make an issue.
I strongly suspect this is because Hobie are well aware that there are still plenty of old models out there and earlier model mirage wells were not as strong. When issues did show up with these (cracks) it was almost always because Turbos were used and the extra pressure helped cause the issues. Thus it follows that flow fins would make this worse.

Newer model wells are stronger (better plastic and more reinforcing), especially those ones that have been re-shaped (rounded ends, as opposed to squared ends). I would have no concerns putting flow fins into any model with the rounded ends. And I'd have no concerns using a single flow fin in any 2012 model onwards
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Re: Stainless Mirage drive pedal cranks.

Post by maverick »

Thanks for the clarification Josh.

As suggested by you I have used stainless through bolts and wingnuts now. (Bunnings 8M 35mm stainless bolts) Removed the clutter and they are the bees knees now.

Feels really solid now, less moving bits and the extra length works very well with the Flow Fin - and they had a good work out on the way back yesterday :roll:
MG stainless pedals and through bolts..jpg
Last edited by maverick on 21 Mar 2017, 20:29, edited 1 time in total.
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Yakass
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Re: Stainless Mirage drive pedal cranks.

Post by Yakass »

Mine did to, as you know. And yep, bees knees indeed ;-)
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Re: Stainless Mirage drive pedal cranks.

Post by Yakass »

Ok, we've received stock and have listed them on our site. Marty is putting together fitting instructions for us now and we should have those available to go with the cranks early next week (not that it's terribly tricky). Supplied with fitting hardware, including end caps and thru-bolts with butterfly nuts. https://slhobie.com.au/gear/hobie-kayak ... dal-cranks
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chrisw
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Re: Stainless Mirage drive pedal cranks.

Post by chrisw »

Yakass wrote:Ok, we've received stock and have listed them on our site. Marty is putting together fitting instructions for us now and we should have those available to go with the cranks early next week (not that it's terribly tricky). Supplied with fitting hardware, including end caps and thru-bolts with butterfly nuts. https://slhobie.com.au/gear/hobie-kayak ... dal-cranks
Just got around to fitting these to my MD180 and there's a small issue I want to raise. I found that it was difficult to set the cranks to either extreme; that is to position 1 or position 7 (I use 7 on the water). After removing them I saw that the cranks were binding with the plastic of the drive housing due to insufficient relief being ground to the end.

This is the relief as it came originally (please excuse the blurry image; I didn't notice until I'd already modified the cranks):
1.jpg
Basically only a tiny amount of metal has been ground away for clearance purposes.

You can see the place where the ends scraped away the plastic in the housing here:
2.jpg
I don't know if it's a manufacturing defect with the particular set I got or whether the MD180 has slightly different dimensions than the one the cranks were tested with, but whatever the cause I had to take to them with a grinder to get them to move freely.
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Re: Stainless Mirage drive pedal cranks.

Post by Munroe »

chrisw wrote:Basically only a tiny amount of metal has been ground away for clearance purposes.

You can see the place where the ends scraped away the plastic in the housing here:
When I did the mod early last year after following shane's guide, I cut the cranks to the same specs as the originals. after finding out the black caps + bolt would not hold the pedal axle due to the difference in shaft thickness, I drilled into the sides to fasten the axles.... much better solution for the stainless setup
Have a chat to SLH or their supplier if you wish to put a grinder to your cranks.... may have been an oversight with your kit, or something for them to implement for future stock.
stock Al' Crank
stock Al' Crank
Edit... noticed you have already put the grinder to them.
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shane
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Re: Stainless Mirage drive pedal cranks.

Post by shane »

As Munroe noted you need to cut angles into the corners of the crank ends so they can rotate to all pedal positions. Just be careful you don't take too much off the corner. I've had a couple of cranks tear through the bottom hole so you need to leave enough for strength in this area.

One other thing if using through bolts in the adjustment holes - don't over tighten them. I've just broken two glide tech drums on the mirage drive where the internal stainless steel has cracked through at the hole point. I suspect this is partially caused by a too tight bolt causing a rigid connection that puts enough pressure on the hole region to break the internal stainless steel in the drum. Below is a photo of the drum with the outer plastic removed. You can see the crack in the S/S where the screwdriver tip is. This is enough to cause the drum to warp when pedaling and the pedal crank to twist.

Image

On a side note this now means I've broken every single component on a mirage drive. :roll:
Last edited by shane on 20 Apr 2017, 21:49, edited 2 times in total.
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chrisw
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Re: Stainless Mirage drive pedal cranks.

Post by chrisw »

shane wrote:As Munroe noted you need to cut angles into the corners of the crank ends so they can rotate to all pedal positions.
Yep, I can see the originals had this. However this new kit already had a small angle ground into the edges (presumably for exactly this reason) and the instructions say to just insert them (no mention of modifications). Hence it's pretty clearly either not enough grinding on the pair I had (which would be a manufacturing defect), or the correct amount was ground but that this amount is insufficient for a MD180 (in which case they need to start saying "don't put these into an MD180").

The amount I had to take off with the grinder was pretty small (I think about an extra mm) but I was surprised I needed to mod them at all since it's sold as a ready-to-fit kit with no caveats about this binding mentioned in the instructions.
shane wrote:One other thing if using through bolts in the adjustment holes - don't over tighten them.
Thanks for the heads-up. I am using the original Hobie clips but am carrying basic tools and the bolts/wing nuts in the kayak in case they become needed. Hopefully the hobie pins will hold up.
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