On the road
Not a museum piece!
Despite this bike having been built over 40 years ago, it still rides like a dream - such is the magic of well built steel components (here the frame was likely manufactured by Vitus). The only components I have replaced on the bike are the brake pads (the original Mafac pads were pretty ineffectual after 35 odd years, understandably), and the bar tape (which also had outlived its expected life span). Even though it can be ridden, the temptation with such a beautiful and also relatively rare vélo would be to never ride it, lest some crucial irreplacable component breaks or the bike accumulates too much dirt and grime.
I am strongly against this philosophy! Buying such a bike and refusing to ride it is depriving it of it's fourth cause! A bike was not built to sit in the warm and dry, it was built to be on the road; especially in the case of a steel bike, where even if the frame catastrophically breaks apart, the magic of the material is as long as you can still find a frame builder they can easily weld the frame to be good as new.
The aesthetic beauty of the bike is obvious when you look at a picture, but that beauty becomes a living thing once the bike is on the move. The tasteful curvature of the forks for example, provide a lovely aesthetic quality to the bike's front-end, however that beauty is even more appreciated when the curve allows the steel to slightly flex and absorb disturbances in the road surface. Or the shape of the brake levers and the cork brake hoods, pleasant to look at but especially beautiful when you're descending and have to slam on the brakes, the ergonomic design of the levers making it easy to brake quickly while maintaining control of the bike.
Shifting
The first thing that jumps out to other cyclists when they see the bike are the downtube shifters: road bikes have for over a decade now switched to integrated shifters in the brake levers, or on non-road bikes some sort of bar mounted shifting apparatus. The Mercier however, has non-indexed downtube shift levers (later models had indexed shifters which would click into position for the various gears). This means that in order to shift gears, you have to reach down taking a hand off the bars, adjust the rear derailleur lever, feeling for the new gear until it slots in, and then adjust the front derailleur as the new angle of the chain often causes it to rattle. Although you rapidly get used to it, doing this on a fast descent or steep climb where the bike is about to flop over is tricky the first few times! Beyond teaching good bike handling, another advantage of this style of lever is that if on a descent, you want to get to your hardest gear you can simply slam your rear derailleur's lever all the way forwards, which will skip however many gears (on this bike, a ten speed 2x5) and go down to the smallest one. No repeated clicking required, just one smooth push!
Braking
The bike does suffer from the usual disadvantages of rim brakes, which is not a discussion in the scope of this post. I will admit that the nature of rim brakes, combined with the fact that the rims are made of chrome, a significantly less grippy metal than the aluminium that most modern rims are made from, does mean that I avoid any sort of fast wet weather riding. Maybe one day I will replace the rims, which I think would be a fair replacement in the spirit of keeping it on the road as long as possible. The original brake setup, which in the spirit of authenticity I have kept, uses the left-front right-rear brake setup uncommon in the Anglosphere.
Toe Clips
Toe clips are the perfect balance of performance and versatility: you aren't forced to wear obnoxious clipless shoes, but you still get to produce power through the upstroke of the pedals by pulling up on the clip. Definitely a very real learning curve getting in and out of them but once you're used to it I truly believe they are the best choice for anything short of competitive riding.
Conclusion
This bike has brought me a lot of joy and has also taught me basically everything I know about bike maintenance; I have spent uncountable hours tinkering and restoring it to peak performance. It might be heavy, it might not be as fast as a modern carbon road bike but I think that it oozes artisanal affection and attention to detail, and the life that it is so clearly full of is hard to put a price on. Put simply, the Mercier 300 is undeniably cool.
Very versatile!