[Tommo]

Not sure this should go in the Fab section... but it involves glue so I spose that counts...

Got 31s, 33s and 35s? Need a speedo which will do ALL at once?

I have 31s right now, but when they wear out a bit more I'll go 33s or maybe bigger. I never had the speedo calibrated for the 31s to start with, and there's no point if I'm going to go bigger soonish. And even when I go 33, I might get a nice aggressive tread pattern which I swap OFF again for road use - with a change in size at the same time. I use my GPS at the moment, but I don't always like leaving it on the dash, depending on where I'm parked, and it's a pain to keep disconnecting it and locking it away all the time.

I don't know much about speedo gears, but they cost $x and for me would then cost another $y to get them installed. How long does it take to change them? Is it easy to do? Maybe I'll get it done with the next set of tyres.

So I needed a speedo that would change with my tyre size, and would be cheap and unobtrusive.

So I got myself a wireless bicycle speedo cheap off the net.
A bit of liquid nails.
I put the sensor on the flywheel thing at the back of the transfer case, where the tailshaft comes out, cos it's raised up a bit and a bit protected compared with putting it on a wheel rim. It's also closer to where the receiver bit is in the cab, with a straight line distance of less than a metre.
A little bit of calibration using the GPS to tell the real speed and altering the 'rim size' entry in the bike computer, and it works like a charm!
HEY PRESTO!
Quickly and easily changable electronic speedo, spit timer/odometer and speed alarm!

And as ugly as it may be, you can't see it anyway unless you're looking at my transfer case.

You could probably use a wired bike speedo too, and take the wire up through the gear lever rubber, if the wire was long enough. You can get one from d$ckless smith for under $10 if you wanted to give it a go.