I haven't done it yet, but keep meaning to:
A simple metal plate bent to whatever shape you need to fit the bars, or with slots cut in it for clamps to the bars, will work. It only needs to be large enough to fit the back of teh TWM, just the flat area.
Remove the orignal 4 screws holding the TWM together.
Get a drill bit that will make a hole just smaller than those screws (the size of the core, minus the threads).
Drill 4 small holes in the plate, one in each corner, that line up with the TWM screwholes.
Use long enough new screws that they'll still seat down into the TWM box just like the old ones did, but also clamp the plate to the back of the TWM.
Alternately, if you don't need anything super nice, you can use any of the thin/narrow but long stainless steel hose clamps (NOT the ones from harbor freight and the like...they're not even tin-quality much less SS
), and clamp the meter to a straight section of your bars by clamping just the ends to either side of the display.
A third method similar to both is two plates, both longer than the TWM, with two holes each end of each plate to either side of the TWM itself. Front plate gets a hole in it for the TWM's display to be seen thru, and rear plate gets slots for clamps, or holes for bolts or whatever mounting method you choose for the bars. Nut and bolt to secure the halves together, clamping the TWM between them.
A fancier version of this you'd extend and curve the plates so they wrap around the curved parts of the TWM, too, with tabs on either end that you bolt together. Depending on your metal bending skills you might even make interlocking tabs for one end and just use a bolt on the other.
Or use a single plate that is curved to match the TWM contours and just has a bolt to clamp together at two corners to secure the TWM inside after you slide it in.
Again, the clamping methods to get that onto the bars or wherever are simple enough.
A very simple no-bending method is a piece of plastic pipe just a bit larger inside diameter than the TWM, so you can slide it inside. A window for the display cut in the face of the pipe, and then either heat the ends and squish them in or glue ends onto the pipe, or thread it and use threaded ends screwed onto them, with a hole(s) for the wires somewhere.
In all cases you could use any kind of clamp that can either be bolted to the TWM's bracket, or passed thru a slot in it. Various kinds of plumbing clamps and electrical conduit clamps are available in hardware stores, or hose clamps, etc.
All of the above could be painted to match or complement the colors of the bike.
I'll post some pic's when i'm done..
