Motorcycle Mirrors for Fat People
OK, here's the background ... I'm a "plus-size" male riding a 2003 BMW K1200GT bike. The GT originally came with the round "Mickey-Mouse ears" mirrors used by several BMW models, attached to the instrument clusters on each handgrip. I had two problems with the stock mirrors. First, I'm wide enough that I couldn't see behind me without some body contortions; the normal view from my riding position was of my shoulders. (Of course, I could tilt the mirrors outward, to avoid my shoulders, but that just exacerbated the issue of not being able to see directly behind me, and increased the aforementioned contortions.) And, secondly, the stock mirrors' lenses weren't wide enough to give me a good field of view out to the sides (unless tilted outward, as mentioned above).
I quickly found that a popular "upgrade" to the GT is the installation of the wide-oval, K12RS-style mirrors. It's a simple plug-n-play substitution, requiring no modification to the bike or mirrors, and the new mirrors were available at my local dealer for about $90 a pair. In addition to having lenses about 25% wider than the stock GT type (although similarly narrower from top to bottom -- about 3"x5" vs 4" round), the RS mirrors attach to the bike via sculpted-plastic, two-rib arms that just look nicer (and more solid) than the spindly, metal-bar, stock-GT mirror shafts. [But, as we'll see later, I soon destroyed that sleek look. :-)] Each KRS-style arm has a rotational friction joint toward the base, which allows the mirror to fold back to the rear upon stiff collision. I suspect that the original GT mirrors would do something similar, just by their metal shaft turning in the bolt hole. One note: the RS mirrors' arms will slightly contact the stock windshield at full lock in either direction, though I don't remember if it happens at all windshield positions. They also tag my Cee Bailey's +6" windshield, but not enough to break anything or interfere with steering.
The RS mirrors sorta' solved either problem, but not fully. Their inside edges more or less correspond in position to the stock mirrors, which means that the outer edge is an inch or so farther out. So, by tilting them in a bit, I could see more behind me than before, but still not as well as I might like. And, by tilting them out, I could see better to the sides, but again not optimally. So, setting aside the first problem temporarily, I continued to address the second.
My first thought was to stick some of the little round, convex-mirror, "fish-eye" lenses to the outside portion of the RS mirrors. That would allow me to see vehicles in my blind spots to the sides, but the stick-ons that were large enough to be useful covered up way too much of the total mirror surface. (I guess I should mention here that, in addition to being old and fat, I'm damned near blind, and wear trifocal glasses.) Also, of course, the big fish-eyes reduced my view behind to less than what I had with the round mirrors. Then someone on the Internet BMW Riders (IBMWR) email list pointed me to Multivex mirror lenses. These are add-on lenses that are flat on the inner 1/2 or more, but convex curved on the outside edges. Once you get used to them, they almost completely eliminate blind spots, allowing you to see a vehicle in the mirrors right up until it enters your direct peripheral vision. The lenses just stick onto the existing mirrors with double-sided tape. There's a thin gap left, but I filled it in on the top and sides with black silicone caulk. The Multivex part numbers for the RS mirrors are 01031LH and 01032RH. I love 'em.
So, now that the side-view problem had been handled, what to do about the view behind? Well, it's simple geometry, really -- the obvious answer was that the spread of the mirrors had to be significantly wider than me (which is saying something, as I'm significantly wide) in order for my reflected views to converge behind me. I perused various internet forums (fora?) for mirror-related threads, and I looked through after-market catalogs for mirror extenders and such. On a previous bike, I had a pair of Saeng windshield-mounted auxiliary mirrors, but I wasn't much impressed by them. I thought I had a hot lead with the Verholen fairing-mounted mirrors, but after exchanging some notes with a gentleman who had them installed on his bike, I learned that their tip-to-tip measurement was no more than that of the RS mirrors. Back to the drawing board ... I bought a couple of small, cheap mirrors at the local motorcycle super-store, and played around with various ideas on attaching them to the RS stalks such that they extended out past the regular mirrors. But, not only did that look cheap and ultra-dorky, the results were very non-sturdy, and usually interfered greatly with the windshield or other parts.
Meanwhile, winter arrived, and I moved my bike into the garage for an extended session of maintenance and farkling. The mirror issue sorta' hung in limbo for a while, until one day I started thinking about somehow extending the actual RS-mirror arms. I measured the upper and lower ribs of the arms for cross-section, taper, and what have you. I conducted thought experiments and made scratch-paper designs for inserting a length of plastic or metal tubing into the middle of the stalk, or even flattening two tubes into oval shapes and lengthening the upper and lower ribs individually. (BTW, I say "I" here a lot, but actually I was with a buddy who was working on his bike, too, and we were constantly bouncing ideas off one another, and kibitzing and whatnot, so most things were sorta' collaborative efforts with constant, real-time peer review -- most helpful.) Anyway, nothing really panned out, and spring was approaching. So, one day, before I could really think long enough to stop myself, I just grabbed a nearby saber saw and cut one of the RS mirrors in half, while it was still on the bike! Holding the severed mirror head and looking at the stub of stalk still attached to the instrument cluster, I thought to myself, "now I really need to get something in place, or I'm gonna have to go order another pair of mirrors (right after I clean all this black plastic 'sawdust' off my bike)".
So, the no-nonsense engineer in me came forward and decided: we need reasonable strength and rigidity, not too much weight, and a sturdy but relatively simple and easy assembly. I quickly decided that the top and bottom ribs could each be extended by a flat piece of metal, and that the plastic surfaces of the ribs could be notched so that the metal extensions would fit more or less flush (on the outsides). I originally was thinking to screw the metal to the plastic, but changed that to a pair of bolts at each end going through both metal plates and the plastic stalk in between. It wouldn't look pretty, but maybe I could find something to cover it.
Grabbing some 1/8-inch steel stock I had lying about in the
garage, I made two "rib extensions" that would extend the
mirrors out an additional four or five inches on either side.
To roughly match the taper of the original plastic ribs, I
cut three sides with with a saber saw (using the existing
edge of the stock for the leading side of the extensions) and
then used a bench grinder and a file to clean up and round the
edges and corners. The resulting dimensions were:
To attach the extensions to the plastic ribs, I again clamped the extensions in place, then drilled a pair of holes at each end of the assembly, piercing upper and lower extensions, and the plastic in between. Note that there is some sort of flat, metal reinforcement embedded within the plastic on the outer end, near the ball joint. Originally, I was going to use regular pan-head bolts, cut to the needed lengths, and maybe acorn nuts on the bottom, to fasten the pieces together. At some point I realized that I could countersink the holes at the head ends, use flat-head bolts, and get a more flush fitting. Along this train of thought, I also realised that I didn't have to use nuts -- since the extension pieces were fairly thick steel, I could just tap threads into the lower holes and the extensions themselves would be the "nuts", again giving a flush surface. And, somewhere along the line, I decided to reverse one bolt at each end, so that one of each pair would thread in from the top, and one from the bottom. So, I redrilled the holes in the extensions appropriately (a smaller size for the holes to be tapped, larger for rest), countersank or tapped the holes as needed, and installed flat-head bolts which were then ground flush (with the Dremel® tool) where they protruded. I ended up using 10-32 stainless steel bolts (just because that's what I had -- purists will want to used a metric size, I'm sure). After everything was assembled and tested, I backed out the bolts a bit, applied some Loctite®, and tightened everything back up.
Again using the Dremel® tool, I went over the
metal pieces, rounding edges and corners such that the
extensions "flowed" as much as possible into the lines of
the plastic end pieces. I rubbed the whole assembly with
my hands, looking for points and sharp edges to grind down.
The end result was a very sturdy, not too heavy, extended
mirror. The look was sorta' robotic-arm-ish, in a geeky
and somewhat dorky way. But, I'm old and fat anyway,
and certainly no fashion plate, so the looks were entirely
secondary. The thing met all of its initial requirements,
and did the job for which it was designed. Mounted on the
bike, the extended mirror arm easily let me see a point
directly behind me, while the Multivex lens still provided
great coverage of the traditional blind spot to the side.
So, with the prototype built and working, I pretty quickly (one evening) did the other mirror. Went for a test ride -- oh my, they're awesome! On a couple of subsequent commutes to work, I was able to clearly see directly behind me (which is a must in rush-hour interstate traffic) with just eye movements, and I still had all of the excellent side vision provided by the Multivex mirror lenses. This mod immediately became one of those "how did I ever live without it?" things.
So, to anyone with a "width" issue in using your mirrors, I can highly recommend this sort of construction, or something similar, as a potential solution. Cost is fairly modest, if you have a pair of RS mirrors and are minimally handy with small power tools. This web page should supply all the instuctions needed, as there's nothing really critical involved. If this idea solves your problem, I'll accept polite applause with modesty and grace (but, if you irreparably screw up your mirrors or your bike, or hurt yourself with a tool or technique, it's all your fault and you're on your own).
Copyright © MMXII by William K. Brummett. All rights reserved.
The background image was sent to me by someone. If it's rightfully yours and needs to be attributed, gimme a yell.