Just inherited a very old tunturi family exercise bike, and it is VERY old but works a treat! Trouble is I have no idea what format the speedometer is in!! Anyone got any ideas? I was told it's miles but I'm not convinced at all an planning on using for training so would be helpful if I knew what units I was measuring in! Thanks

Generally the Speedometer is in miles per hour, that is the standard. If you, when looking at the dial gauge, see the numbers go above 50 then it's in kilometers.

Exercise bicycles will give you a pretty accurate account of Speed and this in turn gives you an accurate account of distance. But this is the distance that wheel traveled, not the equivelant that you would be able to do on the road on an actual bike. Yoiu do not have factors like wind resistance, rolling resistance, and terrain to deal with. You will go further on the stationary bike then on the road if you are judging by distance, as you will be pedaling at a higher speed.

congrats on the inheritance.