After regular oil changes and chain adjustments, motorcycle tires are perhaps the most frequent routine maintenance item on a modern motorcycle. However unlike oil, filters, and chain lube, tires cost a pretty penny – an especially onerous expense in the current economic climate. For many riders on a budget, cutting down on the cost of tires might seem like a good way to stay in the sport without breaking the bank. To this end, a number of strategies have evolved to save money on motorcycle tires. These attempts range from researching the longest life tires on the market to more extreme efforts such as installing car tires on large touring bikes. Some of these practices make good financial sense; others make substantially less sense given the risks.
Among touring bikers, a growing movement is building around the practice of installing low cost car tires on motorcycles. The custom is driven by enthusiasm for the purported benefits, which are said to include greater mileage, reduced prevalence of tire failure, and an “out of the box” style. Self-dubbed “darksiders” swear by the practice.
However, running car tires on your bike is a bad idea. Motorcycle tires are designed to play an integral role in the mechanics of motorcycle performance. Suspension, frame, engine, and tires are all designed as part of a whole. Changing any one aspect can lead to a number of unforeseen consequences. Specifically, motorcycle tires have a profile designed for single-track use (as opposed to dual track vehicles like cars or trucks) meaning they retain their functionality when rolled onto their sides during cornering. Car tires, on the other hand, are less crowned and can slide or fail entirely under the stress of running on their sidewalls.
Another budget-conscious practice involves the use of second-hand track tires for every day road use. Known as “take-offs” these used track tires appear to have substantial tread left on them, particularly down the middle where most road tires first start to show signs of wear. This is because track tires spend most of their useful life on their sides as they carry high-performance motorcycles around a series of predefined turns during a race. After a day at the track, a rider can often obtain a pair of used track tires for a fraction of the cost of a new street set, often less than $50 a tire. Given the price, and the impression that track tires must be better, it’s easy to see how this secondary market developed.
But, like darksiders, take-offs are seriously impaired tires, and are often past their useful lifespan. Intended for limited time use at extreme speeds, track tires are made of different compounds than are street tires. Add to this the fact that they are specifically designed to run within a very narrow temperature band, along with a drastically different profile, and the dangers of running them on the street begin to emerge. Track tires are usually only good for one or two cycles on the track, after which they begin to change composition due to the heat cycling effect and can harden rapidly, losing traction along the way.
Motorcycle tires driven on the street rarely come close to the optimum operating temperature required by track tires. Road tires must function over a broad range of temperatures and conditions. For these reasons, used track tires are a terrible idea for street riding and will actually provide inferior performance.
Even if you believe a non-OEM tire falls within your risk tolerance as a rider, there are additional consequences to consider. Traction control is becoming increasingly common on modern bikes. However, entry level systems do little more than compare the relative speed of the front and rear tires and adjust accordingly. Using the wrong tires, especially mismatched tires, can lead to error codes or unplanned engagement from the traction system potentially leading to a crash.
Furthermore, running inappropriate equipment on your bike may make you a target for litigation. Generally, drivers – and riders – have a duty to equip and maintain their vehicles in a safe and legal manner. This means that you have an obligation to ensure that your tires are appropriate for your bike and usage and that they are in good repair. Running track tires that may lack DOT approval, or putting car tires on a bike for which they were clearly not designed, might turn into a legal liability for you in an accident.
Save a little, lose a lot
Given the risks, both legal and physical, it makes little sense to run inappropriate tires on your bike just because they cost a few dollars less. It’s like the old quote from an experienced ride instructor who, when asked if safety gear was always required, opined, “No – only on the day you crash”. The point is you might know people who run non-standard tires without incident. You might even have experience doing so yourself. Sooner or later, though, the practice is almost certain to catch up with you.
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