Electronic speedometers/odometers do work in both directions. The old cable driven speedometers/odometers ran backwards in while reverse.
Speedotomoter Drive Gear
It'd be rare for a bike to be sold with one, but it's real easy to buy and install a bicycle computer, which will have those functions and more.
Yes. Polar has one for instance. Probably Suunto and Garmin has too. They're more than odometers though, so be prepared to pay nicely for them.
A wireless bike odometer uses sensors to track the rotation of the bike's wheel and calculates the distance traveled. The data is then transmitted wirelessly to a display unit mounted on the handlebars. The benefits of using a wireless bike odometer include accurate tracking of distance, speed, and time, which can help cyclists monitor their progress, set goals, and improve their performance. Additionally, wireless odometers are easy to install and remove, and they eliminate the need for messy and cumbersome wiring.
1
Yes
Km/h
An odometer is a machine that displays distance travelled. Odometers can show any number of digits ans so any number of miles.
The gears inside the odometer broke due to heat and age. You can buy the gears and replace them yourself. Or you can take your car to a place were they work on odometers.
Canadian car odometers transitioned to metric measurements in 1977. This change was part of Canada's broader shift to the metric system, which aimed to standardize measurements across the country. Consequently, vehicles sold in Canada after this date featured odometers displaying distances in kilometers instead of miles.
On older cars with turn dial odometers, yes you can. On newer cars with electronic odometers, no you cannot. It is considered illegal in some states to do this, and bad practice by all.