Mirage Drive clunking

[ictalurus]

My Mirage Drive started making a clunking noise the other day, and I can't figure out what it is. It only seems to happen when I'm going 4.5mph or faster. It kind of feels like the chains are jumping the teeth, but the fins never get off center like they did on my old drive with the metal sprockets. I looked at the sprockets today to see if they were worn, and everything looks fine. I can't simulate with the drive out of the water, and all the adjustments suggested by roadrunner on the Hobie forum seem correct. Has anyone else had this problem? If so, what was the cause?

[jffoley]

A guess... not seated correctly. I'm sure you've checked this but maybe things are loose or worn in than kayak rather than the drive itself?

[surfdog]

check the allen set screw that keeps the center shaft in place. when it gets loose the shaft can move back and forth, the shaft has a flat spot for the allen screw to set against

[ictalurus]

Thanks, gents. It was definitely seated correctly, but checking the locking mechanism is a good idea. I hope it's not that. I really don't want to do another hull swap. There haven't been any leaks at least. Checking the allen set screw is a good idea. I didn't think of that.

[Yak Fish]

You are noticing the issue at high torque.
This has happened to me. It occured for a few times out before the teeth stripped, specifically the primary tooth in the center. If you take the mirage drive out and trap the fins between your legs, use your arms to push the pedals hard. You may be able to see the problem that way...look at the chain. and you may be able to jump the teeth. If so, that's your issue. To be honest, I would just order a pair of the sprockets and replace them. Look in the hobie catalog for the part number and you can type it in to ACK or elsewhere. They are super cheap and worst case, you have a fresh set with little effort and you don't have to worry about them stripping out on the water like mine did since I didn't know better.

There's a possibility that it could be something else but it's not that complicated of a mechanism so the potential issues are limited.

[Yak Fish]

Also, as a result of my experience, I never try and sprint with the Hobie anymore the small plastic sprockets just can't take it.

[ictalurus]

Hmmm... That's sounding the likely problem. That's a good test. I haven't been sprinting, but I really like cruising fast. However, the times I've broken my idler cable or the metal sprockets on my old drive, I was cruising into waves or current, which probably acts like sprinting. I gotta get used to my new drive.

[FRED driver]

check the allen set screw that keeps the center shaft in place. when it gets loose the shaft can move back and forth, the shaft has a flat spot for the allen screw to set against

I had the exact same issue and this was the fix

[ictalurus]

Update: Clunking fixed

As usual, you have to be smarter than what you're working with. I'm always at a disadvantage... I tried Yak Fish's suggestion, and everything seemed OK. I checked the set screw as suggested by John, too. That wasn't it. It turns out the rear cables on the drive were loose. That never happened on my drive with the metal sprockets, so I didn't even think check that. Joe pointed it out to me while we sat in the parking lot at PLO. I tightened the nuts, and the clunking disappeared. However, now I'm kinda worried that those cables are stretching/rusting despite being rinsed after every trip, so I need to buy some spares.

[moc]

I am glad it was an easy fix.

[HJS]

As usual, you have to be smarter than what you're working with. I'm always at a disadvantage...

I think that applies to all members of Humanity. Glad you got it fixed.