My backup bicycle as main one failed recently, so until I get parts to repair my main bicycle, I have to use this (sorry about poor pic):
It is called Jupiter, that is brand of bicycle, it is from 80's and had no gears originally, but I took Sachs Torpedo 3 speed rear wheel and gear selector + cable from another Jupiter and put into this one, then I installed Nokian Rollspeed tires to it, lubricated chain as it had been lot more than 10 years since nobody had rode this bicycle.
Seems to be working fine, even there is no hand brakes foot brake seem to be operating just fine, does not make odd noises and goes as fast as my main bicycle that has 21 gears, I have been thinking that if I could swap single gear rear hub to my main bicycle it would be lot better as it would be 3 gears front and 3 gears back, which would be more than plenty and it would be much simpler, but it is not easily possible.
I will post pic of my main bicycle when I get it working again.
I have 2 Camping and 2 Jupiter which all are similar to this bicycle in photo, one I did found under the pine at my forest, so that is going to take a lot of work to restore.
Then there is one Renault (my main bicycle), which is perhaps Trekking bike, but it is more of city bike, I'm going to do some modifications to that so that it is more of Triathlon bike, but I'm not sure what it will be really with limited resources. 11 teeth rear gear will be installed soon and some new handlebars, also better tires to make it run bit easier, would love to change front gears to something more highway like too, but it might take some time to do that.