mirage drive GT upgrade ... YES!

After your 'persuaded' the link onto the sprocket, is it now captive there or will it now come on and off as easy as the original?

After your 'persuaded' the link onto the sprocket, is it now captive there or will it now come on and off as easy as the original?

I'd bet that after some use it'll loosen up. I wouldn't be surprised if the older (non-GT) were the same, that is, they were hard to "persuade" initially, but easier to pop on and off after a little use.

After your 'persuaded' the link onto the sprocket, is it now captive there or will it now come on and off as easy as the original?

I'd bet that after some use it'll loosen up. I wouldn't be surprised if the older (non-GT) were the same, that is, they were hard to "persuade" initially, but easier to pop on and off after a little use.

Glad you got er done! Now that you mention the details I do remember having the exact same difficulty reassembling my non-GT drive. I had to push really hard on the chain to get it to go back down onto the sprocket.

Interesting stuff... No direct experience with rebuilding Mirage Drives, but I've got a pile of bike shop experience that might apply.

Chains stretch out over time with heavy use, and as they do, the sprocket (cassette) gets worn to the shape of the longer chain. So, old chain on old cassette works OK. Change the chain only, you get skipping. Change the cassette  only, you get skipping. Change both, golden.

Not sure what a new chain would cost, but if you're gonna do it, DO IT NOW.

If you wait and need to change your chain later, your new sprocket will already be worn down to fit your (even more) stretched chain.

We always recommended people buy a new chain any time they changed their cassette. They would think we were trying to sell them more crap, until their chain would start skipping...

I thought the chain has a tension nut?  No?

You can tension the chain as a whole, but I'm talking about the actual individual chain links stretching. Maybe "stretching" isn't the right word, but as a chain wears, it gets longer. The internal surfaces that rub against each other in each chain link get worn down, and that extra "slop" results in a longer chain. Longer chain means fewer links per a given length of chain, which means improper fit to a cassette/sprocket that has teeth spaced properly for a new chain.

If you measure a brand new bike chain then measure an identical model that's been used heavily, they will be different lengths.

I follow you.

The worn bike chain/cassette analogy may not have much application here. Very few links on Mirage chain that fit over plastic teeth. Not the same "stretch" generated from a long bike chain over steel sprocket teeth. Take a new Mirage replacement chain/cable and lay over a used one. I could be wrong here but I think the difference would be very slight. If re-building to a GT it might be good to have new chain/cable more for oxidation on the cable that might weaken it than link wear.

Charles - I think you're probably right that this won't be a big factor, but I thought it would be worth mentioning.

True the mirage drive chain is much shorter, but that means you have the same few links going through the same short repetitive motion many many many times. They may not "stretch", but I'm sure there's some internal wear going on. Whether the sprocket is plastic or metal doesn't really affect the amount of tension put on the links, your legs (and degree of mechanical advantage) do. Mirage drive pedals are significantly longer than bike cranks, so they can generate some pretty hefty forces in that chain.

I actually just did a Google search out of curiosity, and noticed I'm not the first person to mention this:

http://www.bigwatersedge.com/bwevb/printthread.php?t=24376

But this is probably just me overthinking things... I do that sometimes.

Thanks Alex

If I do a GT upgrade I will certainly compare new chain with old to really see if there is much stretch wear. I do think the pressure generated on chain and sprocket on a bike particularly on steep uphill grades is greater than on the drive which pushes water. Plus, unlike road and particularly mtb biking, the chain is free of dirt, mud and grit which accelerate wear. I think Hobie may use Wipperman SS chain. I've heard of bikers going 20 k on that brand so the Mirage drive chain may wear less slowly than the kind of bike chains most of us use.

Where can you buy the parts for this upgrade?

I got a chance to try out the GT upgrade today. This was my first time on the water in many months, I was mostly playing around with my new sail (lots of fun, btw), and was only out for a couple of hours.

Without a side-by-side and longer-term comparison, it's hard to say whether the GT drive actually requires less pedaling effort. But, I can say that the upgraded drive is incredibly quiet and smooth, and for those reasons alone, it was well worth it to me.

Where can you buy the parts for this upgrade?

Sorry for the late response. This is what (and where) I ordered:
https://www.austinkayak.com/search/mirage%20drive%20gt%20replacement

I got a chance to try out the GT upgrade today. This was my first time on the water in many months, I was mostly playing around with my new sail (lots of fun, btw), and was only out for a couple of hours.

Without a side-by-side and longer-term comparison, it's hard to say whether the GT drive actually requires less pedaling effort. But, I can say that the upgraded drive is incredibly quiet and smooth, and for those reasons alone, it was well worth it to me.

I got a chance to put 6-7 miles on my GT upgrade today.  It's much smoother and peddles just a little easier.  The bearings are a joke though.  I put one the sprockets on backwards and when I got it back on the right direction some of the "pencil lead" bearing pieces broke so one of my sprockets is an old one.  Im glad I bought the upgrade, but Hobie needs to step up and quit using cheap ass parts especially when they charge so much for so little.