I recently completed a long distance bicycle ride. The ride took several weeks, was over 1000km and I traveled light with just enough possessions to meet my day to day needs. My panniers were full and when you're carrying everything, all day, along each km, up every hill the weight you carry is important, so there was no room for souvenirs, but I'm a man who likes cheap tacky souvenirs. Things like snow cones of the Eiffel Tower, mini illuminated Statue of Liberty, London Bus eggcups and so on; you get the idea! Sadly the weight concerns meant I was not able to acquire anything along the way, but by the time I made it home the bike drive train was way past worn out, so I replaced it and had the idea to create a clock from the worn chain rings.

This would provide a tacky souvenir, be a good visible reminder of the trip in addition to the lesser function of a wall clock!

Step 1: Parts

The chain rings I had and ebay has many quartz clock mechanisms for few dollars. They come with a variety of styles of hands and typically run from a single AA battery. A scrap of thin wood, say about 3mm thick, roughly 100mm square and some bright coloured paint complete the materials list.

Very basic tools are all that's needed - a saw that can cut a circle, a drill and a paintbrush.

Step 2: Assembly

Making it is pretty easy and needs very little instruction, you're more getting the idea rather than a detailed step by step rundown in this Instructable. The pictures and a few dot points should suffice.

pull the chain rings apart, normally with a 5mm allen key. De-grease and clean them
get a scrap of thin wood, about the same thickness as the gap between
chain rings. The thickness gives the finished clock some depth
on the scrap of wood draw a circle just a bit smaller than
the diameter of the teeth of the small chain ring and cut this circle out
drill or cut out notches for where the bolts will join the two chain rings, you want the piece of wood to be held snugly in position between the two chain rings when the bolts are in place
drill a hole in the centre of the wood, the same size as the spindle on the clock mechanism

paint the wood or apply some graphics if you prefer. I had already painted this blue before taking these pictures
use the chain ring bolts to bolt the two chain rings together, sandwiching the wood in between
insert the clock mechanism from the rear and secure it with the nuts that came with it