Over the years I've owned multiple bike computers (whose things that tell your speed/distance). Each time the head either falls off while I'm riding or I remove it, but lose it somewhere.
I want my next purchase to be one that is permanently affixed to my handlebars so that it never falls off or gets lost. I'm looking for one with strong mounting mechanism. I want to have to get out a screwdriver to replace the battery. I can't seem to find any one on the market that does this. Any help?
To err is human, but to really foul things up you need a computer.
Paul R. Ehrlich
The best computer, is no computer at all! I am sure I will take flack for this, but if all you are interested in is speed and distance, why not go with an old style bike speedometer. Permanent mounting and no batteries. Just watch out for the roaming bands of bike hipster thieves, they may steal your whole bike to get at the speedometer.
I would look for a way to improve your existing mount interface to make it less prone to falling off rather than making it permanent. Adding bits of rubber, sticky back stuff, or possibly even hook and loop tape to keep things in place better.
VDO m-zero mounts permanently (cable ties).
My answer is a little late to the party, but it is worthwhile to note that there were computer (oedometer, to be precise) that are installed directly into the stem:
They are out of production, but who knows, maybe the mold are still in some drawer in some far-east manufacturing site and they will reappear soon...
That screw seems the worst of all possible choices. I can't imagine a way that compromising either the waterproofing or the electronics doesn't seem likely. If it has to be permanently mounted, glue it into the out-front style mount and glue the tightening bolt into the mount. I have no idea how you'd charge it given it would make it hard to access the charging ports but there you go.
That said, I've never had a Garmin fall off be it in a crash or just riding along with the out front mounts. Given it seems what your main problem is that you can't stop losing bike computers I'd recommend that you use a current generation 520 or higher and take advantage of the wireless sync (either wifi or over your phone data) then never take the Garmin off the bike except for charging.
I've not seen one since those old school mechanical odometers that attach to the front axle. I think your best bet is to add a small screw to the mount to lock the computer in place.
If you get something small and pointy like this one, less than 1.5mm across the shaft, you should be able to screw it straight into the mount so that the point hits the computer. I suspect you could do this without drilling a hole first, but I would drill the hole.
If you're lucky the mount will look like this one and you'll be able to put the screw vertically up underneath through non-critical plastic. That way if you do crack it it doesn't matter too much.
It might be worth buying one that has spare mounts available on eBay, and buying a couple of spares. Then you could just superglue the speedo into the mount and cut it out when the battery needs replacing.
No, there are no permanently mounted bike computers.
To slightly misquote what Rider_X has said the best computer is no computer.
Computers are a tyranny that should be resisted.
Velominati has plenty to say on this topic
Rule #68 Rides are to be measured by quality, not quantity.
Rule #6 Free your mind and your legs will follow.
Rule #74 V Meters or small computers only (note that the aforementioned V Meter is a fictional product).
Not to mention Rule #5. (I did say not to mention it).
However, if you want to log rides and distances for historical value, you could use a smartphone app, such as Strava, Endemondo, Map My Ride, etc.
