A few DIY parts for V2 Hobie Mirage drive

It's no secret that Hobie charges a fortune for parts, so I'm always looking to DIY parts. In the past, I upgraded a couple of V2 Mirage drives to GT, which resulted in leftover V2 drums and various other parts. I'd been thinking about trying to assemble V2 drives from the leftover parts, and I was recently able to find a couple of spines for a good price ($38 each), so I got them.

The Mirage drive masts are ridiculously expensive (like $40 each), so I got these 16 inch long 7mm stainless rods and threaded them:

https://www.amazon.com/inches-405mm-Stainless-Steel-Metric/dp/B0CLGV9QJ7/?th=1

I had a 1/2" nickel rod laying around, so I used that for axle that the drums attach to (it's even more stainless than stainless), and I have a 3/8" stainless rod (not pictured) that I'll use for the other 2 metal parts (axle for the fins themselves, and axle for the roller thingy).

The turbo fins and chains are the only parts that I haven't figured out how to do on the cheap. There is a YT video of a guy who made his own fins, so I might experiment with that, but I'm stumped on the chains. If anybody has any ideas, LMK...

Excellent work! I have a couple of V2 drives that are very well worn and wonder what your opinion is on switching to GT assembly. Worth the effort? Easier pedaling for same speed? About the cables I see no fix other than a redesign using all chain or some sort of belting like automotive engines use.

Great start!  What are you planning to use for the spine shaft? 

I've been thinking about the chains/cables for a while.  If I break again, I'm going to get some stainless cable, in the largest diameter that will squeeze through the link in the chain.  Double that over and crimp.  Then for the other end, get a stainless eye bolt and do the same.  Might have to trim some off the threaded end.  But, I think that would be a much more durable solution to a cable than end crimps onto the fittings. 

I am undecided about coated cable vs un-coated.  A coated cable might keep the elements at bay a little longer, but an uncoated cable will show any weak spots right away, and you could oil it to slow rust/deterioration. 

Excellent work! I have a couple of V2 drives that are very well worn and wonder what your opinion is on switching to GT assembly. Worth the effort? Easier pedaling for same speed?

I have not done a side-by-side comparison of V2 vs GT, but once I revive one of the V2 drives, I’ll give it a try. My gut feeling is that there is a measurable difference, but it’s small. What I like best above t GT is that if you replace the delrin bearings with nylon, no lube is needed, and they are completely silent. A squeaky mirage drive drives me nuts!

Great start!  What are you planning to use for the spine shaft? 

I've been thinking about the chains/cables for a while.  If I break again, I'm going to get some stainless cable, in the largest diameter that will squeeze through the link in the chain.  Double that over and crimp.  Then for the other end, get a stainless eye bolt and do the same.  Might have to trim some off the threaded end.  But, I think that would be a much more durable solution to a cable than end crimps onto the fittings. 

I am undecided about coated cable vs un-coated.  A coated cable might keep the elements at bay a little longer, but an uncoated cable will show any weak spots right away, and you could oil it to slow rust/deterioration.

I’ve got a 3/8 stainless rod that I’ll probably use for the other metal components. But I did find a nylon rod of the appropriate size for cheap, so I might test that.

I did see a YT video where somebody did what you describe for the chain. It looked pretty robust. Personally, I’d go with uncoated, as I suspect the coating just traps saltwater and increases corrosion at the point where the coating ends.

Great start!  What are you planning to use for the spine shaft? 

I've been thinking about the chains/cables for a while.  If I break again, I'm going to get some stainless cable, in the largest diameter that will squeeze through the link in the chain.  Double that over and crimp.  Then for the other end, get a stainless eye bolt and do the same.  Might have to trim some off the threaded end.  But, I think that would be a much more durable solution to a cable than end crimps onto the fittings. 

I am undecided about coated cable vs un-coated.  A coated cable might keep the elements at bay a little longer, but an uncoated cable will show any weak spots right away, and you could oil it to slow rust/deterioration.

I’ve got a 3/8 stainless rod that I’ll probably use for the other metal components. But I did find a nylon rod of the appropriate size for cheap, so I might test that.

I did see a YT video where somebody did what you describe for the chain. It looked pretty robust. Personally, I’d go with uncoated, as I suspect the coating just traps saltwater and increases corrosion at the point where the coating ends.

Yeah, I am leaning toward uncoated also.  I think what you describe happened to me for all of my cable failures.  a little saltwater got trapped, corroded the cable, and then it broke. 

That might be what happened to my shaft too - a little saltwater got trapped and caused unnoticed corrosion, creating a weak point.  Nylon is an interesting idea.  Are you thinking a reinforced nylon like the material that Scotty rod holders are made of? 

  Nylon is an interesting idea.  Are you thinking a reinforced nylon like the material that Scotty rod holders are made of?

It’s MDS nylon. I’ll let you know if it seems feasible.

I’ve never heard of that shaft breaking. Was there a lot of rust?
 

  Nylon is an interesting idea.  Are you thinking a reinforced nylon like the material that Scotty rod holders are made of?

It’s MDS nylon. I’ll let you know if it seems feasible.

I’ve never heard of that shaft breaking. Was there a lot of rust?

Honestly, not really.  There was a small amount of surface rust, but not a lot.  There weren't any cavities either, so I don't think it was a casting error.  It happened when I was on the water off Pacifica.  Just a few squeaks, then a loss of half my power.  Since I launched from the beach, I think some sand got in between the sprocket and the spine, which created extra tension in the drive and ultimately forced the break at the weakest link.  After it broke, I still pedaled back to the beach, just slower.  It would only turn one fin at a time, haha. 

Here's a first attempt at DIY cables.

The stainless stranded wire is 1/8" from West Marine (it appears to be higher quality than that used by Hobie) and is about $1.50/foot, the funny-looking (stainless) bolt is M6-1.0 (slightly smaller than the 1/4" that Hobie uses) and cost a couple dollars on Amazon (I flattened the sides using my new-favorite tool, an angle grinder), the ferrules are about $2 each at WM (much cheaper online when bought in larger numbers), and I didn't use the thimbles but they are only about a quarter each.

They have a swage/crimping tool at WM that is free to use. Unfortunately, the crimper is way out a of alignment, and I couldn't adjust it, so I had to use slots designed for smaller ferrules, and I'm sure the result is nowhere near max strength. Not that this is likely to be a big issue in the application, but it should at least make a watertight seal around the wire, and it does not, so there is certainly more chance of corrosion there.

I'll post pictures of it installed next (too many pictures for one post, apparently)...

Here are 3 pictures of it installed. The first is with the pedals in neutral position, then near the extremes. You can see that the clunky ferrule at the top causes the wire to stand proud of the drum.

I think it'll work (I'll test it, and post here), but I've already got version 2.0  in mind. I plan to loop the wire through the eye bolt, but then put both ferrules at the bottom (near the chain, that is). So, the wire will be doubled over along the drum, and will be able to stay snug to the drum throughout the entire stroke. I also want to use a thimble on the bottom (around the chain), but that's going to require a bit more fine work with the angle grinder (better yet, maybe I'll just buy some stainless chain in bulk instead of trying to recycle it from broken Hobie cables)...

Those look great! I bet those are forever cables - that cable looks a lot thicker than the stock material. 

Your V2 idea seems solid too. Did you try to use a shorter eye bolt, or is the cavity too small to fit the ferrule?

Those look great! I bet those are forever cables - that cable looks a lot thicker than the stock material. 

Your V2 idea seems solid too. Did you try to use a shorter eye bolt, or is the cavity too small to fit the ferrule?

Yes, one option would be to use a shorter eye bolt, but the ferule would only fit close to the bottom of the cavity where the bolt rests (if that makes sense), so you'd have very little room for adjustment. It might be possible to strategically file down part of the drum, though, and get a more space, giving it similar adjustability to the authentic Hobie chains. Hmm... might have to think about that some more.

Wrt cable diameter, it's the same as Hobie (both 1/8"), but up to 3/16" should fit thru the eye bolt. It might be worth upping the size to 5/32". So many possibilities...

Btw, I think I'm going to buy my own swaging tool (the crimper), as I can get a good one for less than $50, and the one at WM is well past its usable life. That'll make it easy (and fairly cheap) to experiment with lots of different options.

Interesting on cable diameter - the new one looks larger in the pics. Maybe the color?  I still think the way you built it is going to be a lot more durable than the factory cables.

I figured that the ferrule didn't fit in that space, hence why you made it with the longer eye bolts.

Great work so far - looking forward to your performance reports!

Here is an idea of using cable. This is 1/16 SS trolling wire looped through the chain with the other end secured with a sleeve after running the cable through an eyebolt not shown here. This makes a 1/8 cable and will allow a shorter eyebolt tension adjuster so the cable does not ride "proud" above the pulley. One could sleeve the cable with plastic tubing  if desired . The trolling cable can easily be replaced if broken strands are noticed. Also, a good set of vice grips can crimp the sleeve. I do have that trolling wire laying around.

What about using dyneema to connect the chain to the drum, and avoid the SS cable all together?