A few DIY parts for V2 Hobie Mirage drive

This is awesome!

I re-re-tested the 90-degree twisted chain Mirage drive, and it has an annoying clicking noise. I can't seem to reproduce the click when the drive is out of the water, but I think it is caused by the "twist" links sliding against each other.

I came up with this alternative approach, which is basically a twisted figure 8 made out of bronze (I got some bronze scraps for free at the local metal store, bronze is a lot easier to shape than stainless, and it plays well with stainless). I've only fabricated one so far, and I need 2 per chain, so it might take a while...

If anybody has suggestions as to a alternative that will accomplish the same thing, LMK. The part where the link passes thru is 1/4", while the width at the widest point is about 7/16".

The first picture is an intermediate view, after I'd cut a slice out of the bronze block and started shaping it. The 2nd picture is the final result connecting the chains together.

It seems extremely solid, and I'm confident that it'll eliminate the click.

looks good. Do you thing a section of motor timing belt might also work as a connector for the chains?

Good work nowhereman! Hey are you the one that was making the stronger stainless pedal cranks for the v2 drive? If so I'd like to buy a pair if you still have some laying around. I'm in Fremont so you’re not far from me.

looks good. Do you thing a section of motor timing belt might also work as a connector for the chains?

That might work, but it would have to be teeny-tiny...

Interesting solution - curious to see the results. Nice work carving that brass link!

Looks good. The only concern is that the brass is softer than the metal chain. Perhaps installing a roller between the brass and the pins of the chain will help prevent the brass from wearing? Also, Lube it up with some chain lube for dirt bikes. It will not sling off and is waterproof.

I went to the SC harbor for a brief test-run today. I only have one cable-less chain, so the other one was just a regular Hobie cable/chain. It worked great and was silent. I think it's a winner, but to be sure, I'll need to make another one and test it out with a pair of indestructible chains.

In this brief video, you can just barely see the brass twisted figure-8 things come out of the water at the bottom of the pedal stroke. And, before you ask... No, I was not naked!

https://youtube.com/shorts/0XxPYW0CO48

Looks good. The only concern is that the brass is softer than the metal chain. Perhaps installing a roller between the brass and the pins of the chain will help prevent the brass from wearing? Also, Lube it up with some chain lube for dirt bikes. It will not sling off and is waterproof.

I hadn't thought about that, but at least it is in a visible location, and it should be easy to detect excessive wear. In any case, I might try to make them out of stainless. I think the main part of the work (for which I use an angle grinder with sanding wheel) will be almost as easy with stainless. But, the fine detail stuff (using a file) will be more difficult.

Good work nowhereman! Hey are you the one that was making the stronger stainless pedal cranks for the v2 drive? If so I'd like to buy a pair if you still have some laying around. I'm in Fremont so you’re not far from me.

I haven't made any out of stainless, but I have made a bunch of them out of solid 6061 aluminum and even made a few out of solid 7075 aluminum. I'm sure that even Charles Atlas could not break solid 3/4" 6061 aluminum and 7075 is way overkill. I have several of them (6061 alloy) around...

Good work nowhereman! Hey are you the one that was making the stronger stainless pedal cranks for the v2 drive? If so I'd like to buy a pair if you still have some laying around. I'm in Fremont so you’re not far from me.

I haven't made any out of stainless, but I have made a bunch of them out of solid 6061 aluminum and even made a few out of solid 7075 aluminum. I'm sure that even Charles Atlas could not break solid 3/4" 6061 aluminum and 7075 is way overkill. I have several of them (6061 alloy) around...

Awesome! Sent you a pm

This twisted chain mod has been driving me nuts! It seems incredibly solid, and it works great out of the water. But, with actual pedaling, it has an annoying popping noise (see the video, with the sound turned up). About a dozen trips to the SC harbor has not resolved the issue.

As you can see in the picture, I've stripped it down as much as possible, in an effort to eliminate possible sources of strange sounds. I've even tried a couple of different spines (there are 2 different styles) and that made no difference. The only thing that helps is to tighten the chain, but it has to be extremely tight to eliminate the sound, to the point where it adds resistance when pedaling.

It seems to me that it is caused by the teeth of the gears not quite aligning when there is the slightest bit of slack, causing it to click/pop when it slips back into place. I do get this effect on rare occasion with regular Hobie cable/chains, but it's not as pronounced, and way less common.

Anyways, if anybody has any ideas, let me know!

https://youtube.com/shorts/c95drKm8-3s

If the pedal stroke travel is long enough to allow the "upper" chain to contact a tooth on the gear and hang up a bit that could cause the noise. If not that I would think the connector between chains might be binding on a pedal stroke. Really appreciate the effort in this.

Interesting. Sounds like there is play there somewhere, that is taken up when you change pedal direction.

Just spit balling here. Your custom link looks like it doesn't have any room for play, and the position of the custom link doesn't seem to interfere with the drum. The chain doesn't look like it is getting any side loading.

Is it maybe between the sprocket/fin interface? Or maybe where the chain is rolling around the edge of the drum? That would possibly explain why it goes away when very tight. Maybe a piece of thin delrin or other very slick slick material could help.

Overall though, very cool that it is working! Great work!