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Discussion Starter · #1 ·
I’m working on repairs to my left mirror after a buddy cracked the stalk while walking by the bike and bumped it.
Having previously noticed a crack on the bottom of the stalk when I brought the bike home early last year and finding the cost of replacement mirrors was quite high and they look easily damaged and pretty susceptible to abuse. I thought there would be individual components available but they aren’t to my knowledge which leaves us to buy new mirrors, spend time hunting for used complete ones or we have to hunt for used components which seems risky.

I began looking the second or third options to build up a good set of replacements for the day when the inevitable swap became necessity and I found a good local guy nearby me that had a pair of decent used ones from his old ST2 which I got for $100, along with a few other bits and I was fairly pleased, at least until the package arrived - although the right side was pretty clean and the stalk is in great shape, the left one (the one I really needed) is cracked worse than my current mounted left mirror!

So while reading thru the archives here, with my acquired spares and a set of new springs from Mike Shannon that just arrived, I'm back to finding another left stalk again which has become my biggest problem and I thought I’d go fishing around here for opinions to source, repair or improve on these “weakest link” parts of the mirror assembly, IMHO!

Forgive me if I'm overthinking this, but after looking at the stalks It looks to me the likely issue is with the thin walls these ABS Stalks are molded with affected by spring tension, and although the mirror head itself fits nice and tidy into the upper small/ top end, the large/ fairing end is a different story - and the larger mass of the head appear to transfer any load/ movement against the springs directly down to the joint at the big end of the fairing and the aluminum mounting base which has a more pronounced taper to its shape, resulting in a small area of support/ contact at the stalk open end so that the stress eventually causes the stalk to crack there. This is likely made worse by both age and UV exposure until the day it finally lets go.

I’m interested in how many around of you here have experienced the cracking and just what ideas are out there to prevent, repair or simply shore them up to prolong the breaking? Sorry for being long winded, and thanks in advance.

BTW - I first thought about filling the large tube portion of the stalk with expanding spray foam but dismissed that due
to the lack of strength, and now considering a mix of epoxy resin w/ micro balloons to lighten it up some...


Mitch
 

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Mine are both cracked and missing a few chunks on the underside of the stalk. Not too visible, fortunately. No idea if it happened under my ownership or previous. Pretty common I believe.

I've seen these pop up a number of times as alternatives. I hunt randomly on ebay but they're getting pretty hard to come by in the right color and not already damaged.
 

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Discussion Starter · #4 ·
I suppose I'm partial to the original Ducati mirrors, and noticed on both sets of mine that the spring is routed thru the fwd tube of the stalk, which leaves the larger rear tube open for mod's to lower the odds of breaking...
That's why I mentioned the use of foam and epoxy as fillers to make the stalks more robust. I was hoping somebody has tried this idea.
I also quizzed Mike Shannon and he had a good idea, he says he drilled thru the big end of stalk (on the top of the installed mirror) and into the aluminum mirror base and tapped that for using a 3mm truss head screws in a couple spots, which would minimize the stalk moving independently of the base.
 

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Discussion Starter · #5 ·
Shameless bump, cuz I cant believe there aren't a bunch of you that have not experienced this issue on an ST.
My apologies if I'm off base - but it seems too easy give an accidental nudge to the mirror assy while moving the bike around in the garage, truck/ trailering it or just moving around the bike while detailing/ working on it.
I'm delayed due to recent health problems and running out of riding time with winter coming fast where I live. I still am looking for ideas from the creative folks around here on the fortification of the thin ABS stalks, where all that spring load comes to bear, the cast alum base attached to the fairing...

Mitch
 

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I somehow doubt the original part is still available, but have you looked into that route? https://www.ducatiomaha.com/ is a good place to buy original parts.

Have you looked into ABS "welding?" I have plastic welded several things over the years with varying levels of success. Might be worth looking into.

I did a quick ebay search and only came across a couple original mirrors - one price over $250!!! o_O With the low stock and high price, I can see why you haven't just pick some of those up there. I did come across these, though, like Pascalfd's mirrors: Matte Black Motorcycle LED Turn Signal Mirrors For Honda VTR 1000 Ducati ST3 | eBay With the integrated turn signals and the cheap price, I'm half temped to get a set and try them out myself!

As for your rebuild and fortification, I've never tried that route myself, but don't see why it couldn't work. The added weight of a "solid" stalk wouldn't be that much, I don't think. You might be able to get away with just fortifying the lower section where the spring attaches and leaving the rest hollow?
 

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Here's a pair of used stalks for $70 plus shipping. Though I'm sure the 20+ year old plastic is just as brittle.

As far as re-engineering them, I haven't a clue. I can only assume they were designed this way so that they would give when bumped versus cracking the entire nose fairing.

Obviously not OEM, but you could go with CRG bar end mirrors and block-offs and remove the problem entirely.
 

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Discussion Starter · #8 ·
Thanks for adding some thoughts to my challenge!
I’m still fighting some back trouble which is very distracting and killing my energy to keep attacking this and several other issues. As I mentioned in my last “bump” reply I like the OEM mirror style, it is consistent with the rest of the ST’s looks so I’m not really interested in the newer style mirrors. I also at the age where my lack of appreciation for most contemporary style leads me to appreciate the classic looks even more and I have the same views for the newer car designs - I find most “edgy”, contemporary automotive designs Butt Ugly (I.E., latest Toyota Prius), not that there aren’t some exceptions (latest Toyota Supra😊).

As I mentioned earlier - I like the original stalk/ mirror style enuf to pursue some improvement and have been thinking about how to go about the epoxy mod to fill of the larger of the stalk’s two cavity’s, leaving the smaller one open for the spring.

And I do appreciate the suggestions for the eBay mirrors w/ LED indicators, thanks KB02 – Yes, I did contact DucatiOmaha, and was told “no individual mirror parts are available” and I “need to order the complete mirror, which was about $220.00 + shpg”. Likewise, thanks to [email protected] - I’ve been crawling around eBay, and craigslist and that $70 buck set looks to be whole and might be used as a complete “mold” with which one could try the epoxy fill idea I’m trying to hatch. That would save the need which I also have - to patch in missing pieces from my own mirror as well as a spare I bought last year, which is missing an even larger piece from the bottom side. I think it important to find an epoxy that will meld with the ABS stalk material to prevent that from flaking.

I’m still thinking of using micro-balloons in the epoxy to reduce the weight, and adding a solid tube shape up the cavity center for more weight savings and then covering the stalk side of the cast metal base with something like Syran Wrap to act as a mold release prior to inserting it into the stalk to serve as a “bottom” of the mold, allowing the epoxy to fill down to the covered base and building wall thickness at the bottom where I believe it’s needed, since every crack I’ve seen seems to start there every time the mirror is bumped and is working against the mirror spring pressure at the bottom edge.

More to come, Mitch
 

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Not that I'd fill that space with anything...but if you'd want to...consider the spray foam (GreatStuff) from your local building supply center. The material will stick to insides, fill the void, and be filled with lots of bubbles to save weight.
 

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Discussion Starter · #10 ·
Yeah Mike, that spray foam was my first thought filler medium ,due primarily to the finished weight
(see my starter post). However I began to wonder just how structural it becomes once it sets up, and
in my experiences with it I think it might not have very much strengthening going for it other than
the energy sealing factor, and I can't imagine it having any strength contribution to the larger end of
the stalk where it meets the fairing. I suppose trying it out on an already broken stalk might be a worthy
test though. Like this mirror I bought last year hoping for useable parts
 

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Discussion Starter · #13 ·
Thank you - it's nice of you to bump this thread, I recently endured back surgery so all I can do these days is think about besides riding, is this fix and several others that I've not been able to get too!

I'm not sure the foam will be strong enough where it appears most of the cracks begin - which seems to be at the the lower edge of the stalk, where it meets the rubber pad on the fairing panel. I believe each time any force large enuf to allow the mirror assembly to move will transfer the load down to that thin base and unless the foam has the needed strength it will probably not be able to prevent cracks to form, especially as the stalk ages and UV works against the plastic (my ST4 is 22 years old... any bets?).

Unfortunately the alum mirror mounting base has a taper that leaves very little space to build up the wall thickness of the stalk at that end and another reason I'm reluctant to even try the foam (plus I only have a couple spares to use for a test).

I figured using resin would allow it to creep/ flow easier to that lower end prior to setting up, instead of guessing at the foam's expansion rate down where I won't be able to see it. I think my plan would be to screw the alum mounting base to a piece of plywood scrap and cover it with plastic wrap to serve as a mold release, then install the stalk and fill with resin mixed with a mild (slow) catalyst to keep the heat at a reasonable level while curing.
I have yet to decide on what to do about minimizing the resin quantity (weight) other than micro balloons and/ or anything like a cardboard straw to create voids, perhaps one in the center of the rear stalk cavity, and another for the spring in the front.

Thanks again,
Mitch
 
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