Topic: mirage drive GT upgrade ... YES! (Read 4569 times)

February 28, 2015, 07:48:46 PM

I got the parts to upgrade my V2 mirage drive to GT and I can't seem to get it to work. Strange as it might sound, the chains don't want to properly seat on the sprockets on the new GT parts.

The first picture shows the GT sprocket, while the second picture shows the chain "on" the sprocket. If you look closely, you'll see that on the top side of that second photo, the chain is riding up over the teeth. No matter what I do, this happens every time. The next two pictures are of the original (non-GT) part, where the same chain works just fine.

I've disassembled my mirage drive several times and always reassembled it without any trouble at all. So, at least wrt the mirage drive, I don't think I'm a complete doofus. But this is starting to making me wonder.

Any ideas?

February 28, 2015, 07:53:54 PM #1

I'm pretty sure I've had this happen to me before after tearing down a drive unit. If I'm remembering correctly the problem was I didn't have the chain centered. Wish I could be more helpful but I do for sure remembering this happen & I did end up getting it back together.

February 28, 2015, 07:56:12 PM #2

Hmmmm......I just looked at your pics a little more closely & one of the teeth seems to look a little wider than the others on the new sprocket?

March 01, 2015, 08:30:05 AM #3

Quote from: Salty. on February 28, 2015, 07:56:12 PM

Hmmmm......I just looked at your pics a little more closely & one of the teeth seems to look a little wider than the others on the new sprocket?

Thanks for the reply.

Yes, that's true that the center tooth is larger. That's actually also the case on the non-GT version too, but it's maybe not quite as pronounced and not as easy to see. I believe the idea is that you should center the chain over that bigger tooth first, then the rest of it should easily fit, and that seems to work fine for the non-GT case. But for the GT version, that doesn't work---only one side or the other will seat, not both.

Somebody on the NWKA has done this upgrade, so I'll see if I can get some additional info there. I'll post details when I get this figured out...

March 01, 2015, 12:01:52 PM #4

The guy on the NWKA forum had the same problem, and he got it to work. So, it does fit after all, although it took more force than I could get with my bare hands. Anyways, it's done.

I'll report back once I get a chance to try it out. For now, here's some additional photos of the bearings and the completed project. Other than my struggles with the chain, it's an easy mod. As always, let me know if you have any questions.

March 01, 2015, 01:39:37 PM #5

What were the cost of the parts to upgrade?

March 01, 2015, 01:57:02 PM #6

Quote from: Great Bass 2 on March 01, 2015, 01:39:37 PM

What were the cost of the parts to upgrade?

It's $130 which by Hobie standards seems like a bargain...

March 01, 2015, 02:03:15 PM #7

Yeah that's cheap for Hobie parts. To buy the whole drive costs more than a Suzuki 2.5 HP outboard. How are the roller bearings lubricated, oil or grease and how easy are they to access to service? Reel bearings are often the first to corrode and fail so smoothness and efficiency comes at the cost of more maintenance time. I only like reels with only 2-3 bearings for that reason.

March 01, 2015, 02:05:24 PM #8

Looks like all the new parts are gray and made of plastic. Are those plastic roller bearings on a plastic bearing race and stainless steel shaft?

Looking at your photos gives me ideas.... what are you planning on doing with the original parts? Perhaps machine out each end and install sealed bearings in a stainless steel cage so there are no moving parts on plastic at all.

Two bearings like this at each end should be able to replace those roller bearings and permanently filled with waterproof grease on your old parts with a little machining work.

It will be interesting to see how well those rollers and new bodies hold up to sand and other contaminates.

March 01, 2015, 02:15:38 PM #9

Quote from: Great Bass 2 on March 01, 2015, 02:03:15 PM

Yeah that's cheap for Hobie parts. To buy the whole drive costs more than a Suzuki 2.5 HP outboard. How are the roller bearings lubricated, oil or grease and how easy are they to access to service? Reel bearings are often the first to corrode and fail so smoothness and efficiency comes at the cost of more maintenance time. I only like reels with only 2-3 bearings for that reason.

That's an excellent question. I don't know what Hobie recommends for lubrication---I plan to call tomorrow to find out. But, I didn't use any lube and carefully cleaned all grease, etc., before installing. It seems to me that you want to be able to rinse out any grit that gets in there, and any lube is going to trap some of it, requiring a complete take-apart and cleaning. Those bearings are just plastic, I believe, and certainly as far from sealed as could be. Gunk is definitely going to get in there.

It's kind of nifty, but it seems to me that the real question is whether it'll be more trouble than it's worth to maintain...

March 01, 2015, 02:20:30 PM #10

Quote from: Ski Pro 3 -- Jerry on March 01, 2015, 02:05:24 PM

Looking at your photos gives me ideas.... what are you planning on doing with the original parts? Perhaps machine out each end and install sealed bearings in a stainless steel cage so there are no moving parts on plastic at all.

The trouble is that there is not a lot of extra material to work with, so I suspect you wouldn't be able to drill it out enough without weakening it. But it is something to consider...

March 01, 2015, 02:33:31 PM #11

Quote from: NowhereMan on March 01, 2015, 02:20:30 PM

Quote from: Ski Pro 3 -- Jerry on March 01, 2015, 02:05:24 PM

Looking at your photos gives me ideas.... what are you planning on doing with the original parts? Perhaps machine out each end and install sealed bearings in a stainless steel cage so there are no moving parts on plastic at all.

The trouble is that there is not a lot of extra material to work with, so I suspect you wouldn't be able to drill it out enough without weakening it. But it is something to consider...

Well, certainly with the new GT parts, they enlarged the opening for the roller bearings. Probably stronger materials were used than stock. (At least let's hope so) But either machine out a recess for a sealed bearing on each end of the openings of the old parts, or replace the rollers with a sealed bearing. Here's a crude mock up of what I'm talking about, modifying your photo;

I would bet you could measure what you have with the roller bearing set up and buy a press-fit sealed bearing that would be both stainless steel and perm-sealed with waterproof grease from a bearing house for about $5. Maybe less.

March 01, 2015, 03:32:40 PM #12

Quote from: NowhereMan on March 01, 2015, 12:01:52 PM

The guy on the NWKA forum had the same problem, and he got it to work. So, it does fit after all, although it took more force than I could get with my bare hands. Anyways, it's done.

So if you couldn't get it done with your bare hands, how did you get it done?

March 01, 2015, 04:25:54 PM #13

Quote from: bmb 2.0 on March 01, 2015, 03:32:40 PM

Quote from: NowhereMan on March 01, 2015, 12:01:52 PM
The guy on the NWKA forum had the same problem, and he got it to work. So, it does fit after all, although it took more force than I could get with my bare hands. Anyways, it's done.
So if you couldn't get it done with your bare hands, how did you get it done?

I used a flat-head screwdriver to press in the link adjacent to center/bigger tooth, then the rest of it went on easily.

March 01, 2015, 06:00:12 PM #14

Quote from: Ski Pro 3 -- Jerry on March 01, 2015, 02:33:31 PM

I would bet you could measure what you have with the roller bearing set up and buy a press-fit sealed bearing that would be both stainless steel and perm-sealed with waterproof grease from a bearing house for about $5. Maybe less.

That's an interesting idea, and I was wondering why Hobie didn't do something like that. As you say, the cost would probably not be prohibitive. It makes me think that they think that the plastic roller bearings are a better approach...

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Topic: mirage drive GT upgrade ... YES! (Read 4569 times)

NowhereMan

Salty.

Salty.

NowhereMan

NowhereMan

Great Bass 2

NowhereMan

Great Bass 2

Ski Pro 3 -- Jerry

NowhereMan

NowhereMan

Ski Pro 3 -- Jerry

bmb

NowhereMan

NowhereMan