There are so many factors to consider to understand why bikes made these days are much easier to maintain as compared to the early 19th century bikes. One of the main factors is the improved metallurgy of ores used in the production of the parts are of a much higher quality, don’t corrode as readily, and are much better suited for the job (better tolerance to wear, heat, and stress). Precision machining has improved as well, so tolerances are much, much tighter, resulting in better parts that fit together and stay together better. Did you know the acceptable tolerance for a door on a Model T was a quarter inch? Imagine that! Rubbers are better, so seals perform better and last longer. They don’t split and break down as easily. Rear main seals used to be of a type called “rope” or “wick” seals. They often leaked, even when the vehicle was new. Replacement means removing the engine and disassembling it completely, to the point you can remove the crankshaft. Now they’re one-piece neoprene and they last almost forever. All the seals and gaskets are this way: they’re just so much better today than they ever could have been in the past. The most common gasket material used to be cork; now it’s a type of synthetic rubber. That’s better living through chemistry (well, materials science, anyway). And speaking of chemicals, let’s talk about lubrication. Motor oil is a modern miracle. It gets better and better every year. There’s a service grade on the back of every bottle of motor oil; currently, we’re at grade SN. SA is what was in use in the 1920s. Compared to modern oils, the old stuff was prone to break down quickly when exposed to heat, didn’t suspend particles nearly as well, was non-detergent, wasn’t foam resistant, and didn’t lubricate nearly as well. Yet the internal conditions of a combustion motor were as harsh in the 1920s as they are today. New engines seal better and deal with crankcase fumes better as well–what’s called “blow-by” would escape the combustion chamber and enter the crankcase and poison the oil over time. There’s less of that now and it’s managed better (via Positive Crankcase Ventilation valves). Bad oil means increased wear. You know how cars today all have six-digit odometers? They used to have only five places because it was so unusual to have a car last 100,000 miles, and if it did, it was way past worn out. Today 100,000 miles is just expected. The better motor oils of today are a major factor in this. This is fun: early Harleys used what was called a “total loss oil system.” So you know how you put four quarts into your engine and then in 3,000 or 5,000 miles you drain out those four quarts and put more in? Didn’t used to work like that. The oil would splash around a little bit and be ejected overboard, usually spit out on the chain to keep it lubed. You had to check how much you had at every fuel fill. Heat is an enemy of oil, and old motorcycles were all air-cooled. The back cylinder always ran a bit hotter than the front one just by virtue of having less air passing over it. So at the same time, that modern oil can be made to resist heat better, modern motorcycles don’t have to run as hot because they can be water-cooled. That’s a win-win. Bearings and the grease that lubricates them have both improved significantly. Grease is like oil–newer stuff is better. Modern grease doesn’t thin out over time, resists moisture and heat, lubricates better, lasts longer. The bearings are made out of better metal. It’s all high-polished chrome stuff. It’s harder, it resists heat better, it tolerates higher speeds, it lasts longer. This is true of engine main and rod bearings as well as wheel bearings. Hell, most bearings you buy today (and that are installed on your vehicle) are “lubed for life.” They’re sealed and designed to last the life of the vehicle, or be replaced along with the entire hub. There was a science to lubricating wheel bearings, and they had to be given the correct amount of pre-load when re-assembled. And disassembly/reassembly was required whenever the brakes were serviced. Brakes last longer, too, and perform better. Drum brakes are a bit more complicated than disk brakes and are hardly used anymore. But the important thing here is that the maintenance on disk brakes is much, much easier to perform, and because modern brake friction surfaces work better and last longer, that maintenance is required less frequently. Oh, and we’re all so spoiled by modern self-adjusting brakes that I almost forgot: you’d have to adjust the brakes to make up for the slack induced by normal wear on the brake shoes. Tires perform better and last longer. They don’t just suddenly blow out like they used to. The spokes on the wheels needed to be checked and adjusted like on bicycles. I know, I never do it on my bicycles either, but they’re built better today than they used to be, too. I actually don’t know how to operate a spoke wrench or how to true a rim. But on a motorcycle in the 30s or 40s or 50s, you’d be expected to. The big thing is probably ignition. Old vehicles–cars and motorcycles both–had breaker points ignition systems that required regular attention and adjustment. After a few thousand miles, the mechanical breaker points would start to weld together and stick, and you’d have to roughen them up with Emory cloth or replace them. And when installed, you’d need to set dwell angle. Condensers could and did go bad, so that’s another part you’d have to watch out for. Motorcycles of the age we’re talking about here wouldn’t even have had automatic spark advance, you’d have a twist mechanism on the opposite handlebar that worked like the throttle to advance or retard your spark. (Here’s an explanation on how to start a 40’s Indian.) And of course, distributor caps and rotors were used back then, and they were wearing items, too. Modern ignition systems are all solid state: a computer fires the ignition coils at the appropriate time. Cams, rotors, and the rider’s ear were all used to figure out appropriate timing back then. Engines ran much dirtier than they do today, in part because of all the manual adjustments the rider would have to make by ear, and in part, because the gasoline contained lead and wasn’t as precisely formulated as today’s is. As a result, spark plug changes were a much more frequent occurrence. Carburetors would need adjustment for altitude changes–you’d have to change the jets to ones suitable for the thinner air at higher elevations, or for thicker air at lower altitudes. Choke adjustments were manual, too–many still are. Valves needed routine adjustment. This is still the case for some motorcycles, but not all of course. Not mine, thankfully. But in an era when motor oil barely lubricated, hydraulic self-adjusting valve tappets were science fiction. Valve seats were softer than they are today. The valve faces would have to be ground to account for the wear they would suffer in use, and they’d need to be cleaned of carbon at 5,000-mile intervals. Filters! Filters used to be paper or foam elements in an oil-bath, like on lawnmowers. Batteries! The maintenance-free battery is a fairly recent invention. Automotive batteries used to have removable caps so you could inspect the cells and keep the (distilled!) water at the correct level. The plates have to remain submerged. The water boils off and evaporates under normal operation. The acid level has to be monitored, too. Summing Up Old motorcycle engines were constructed of weaker metal Corrosion was much more aggressive (modern metals are treated to resist better) Oil levels needed to be watched carefully Modern bikes don’t overheat as readily because they are water-cooled and better-engineered Chassis and bearings needed regular lubrication–they needed greasing at regular intervals Brakes didn’t work as well; brake shoes didn’t last as long Brakes needed manual adjustment to take up the slack created by wearing brake shoes Wheel bearings needed careful assembly–too tight and they’d overheat and bind up; too loose and they’d fail prematurely Wheel bearings needed regular re-packing of grease, usually once or twice per year Wheel spokes needed to be kept at the correct tension, and it was expected that an owner could perform this task Ignition systems were entirely mechanical and needed regular attention and constant adjustment, and featured such components as distributor caps, rotors, and contact/breaker points that wore out in regular use Spark plug changes, or gap-and-cleans, were a regular thing Valves needed regular adjustment: tappets needed to be set with a feeler gauge and the valve faces needed to be cleaned of carbon and re-ground Even filters were expected to be maintained and re-used Batteries required maintenance, too Nothing was expected to last more than a few years, and usually, nothing did. So these are the major factors which have improved the life of motorcycles and made it easier to maintain them. If you liked the article then do share it!