Passenger Tires on Motorcycles: Why You Should Stay Away from Dark Side Riding
The use of car tires on motorcycles is referred to as “dark side riding,” and it is a hotly debated topic in the rider community. While some riders swear by their passenger tires, others dislike the altered handling experience that these tires create.
When motorcycles were first invented around World War I and II, they used the only forms of tires that were available at the time. As more and more iterations came out, however, tire manufacturers recognized the opportunity to create a whole new type of tire.
Motorcycle tires nowadays are uniquely fitted to perform tricks, handle off-road terrain, zoom through rainy urban traffic, and more. But rather than using the prescribed tires for their motorcycles, some riders opt for dark side riding with the use of passenger tires instead.
- Just one visual comparison between passenger and motorcycle tires will reveal that they have many differences. The most obvious contrast between the two is their shape. Motorcycle tires have a leaner, more V-shaped build that allows riders to corner and lean when necessary. Conversely, when examining a car tire, the look is much boxier from the back because the tire’s width remains equal at all heights.
- The next difference is in their construction. Tires are complex products that are made of many materials, but motorcycle tires are made from a larger variety of materials. Passenger tires tend to be made of the same compounds throughout, given that they are supposed to retain the same shape all the way around.
- The sidewall on passenger tires does not have the structure that it needs to perform motorcycle maneuvers. Its lack of strength makes it a less-than-ideal component to add to any bike, especially if that bike will be used on precarious terrain.
- When it comes to cost, passenger tires are much less expensive than motorcycle tires, coming in at about half the price. Because of the initial cost savings and the fact that car tires last longer than motorcycle ones, it is easy to see why riders put them on their bikes.
But there are several reasons why you shouldn’t put a passenger tire on a motorcycle. These tires are intended for completely different handling needs and drastically changing your tire can lead to possible vehicle malfunctions.
Avoid the Dark Side of Riding
Functionality and safety are at the center of why you should not put a passenger tire on a motorcycle. Unless you compete in autocross events with your car, it is unlikely that you will be transferring enough weight to any side of the vehicle to cause it to lean. However, motorcycles are a different story because they are specifically designed to lean.
Tire manufacturers created motorcycle tires for this specific reason. It is important that any tire on a motorcycle is able to:
- Withstand increased sidewall pressure when leaning
- Maintain proper road grip
- Adapt to changing terrain without losing structure
Motorcycle tires have reinforced sidewalls and enough “give” to allow them to perform well on all types of terrain and from all types of angles. When you put a passenger tire on a bike, it cannot protect itself from the sidewall pressure.
All of the strength and structure on a car tire is in its contact path while the sidewalls have zero reinforcement. As a result, when a bike with a car tire leans over, the entire tire goes with it. This leaves little rubber on the pavement and decreases the overall grip.
The overall hassle of mounting and handling a passenger tire on a motorcycle makes it a bad idea altogether. Oftentimes, car tires require much tweaking and finessing to accommodate a motorcycle wheel. Once they are on, riders tend to see noticeable differences in the handling.
Legal and Safety Implications of Dark Side Riding
From an insurance standpoint, having a passenger tire on your bike can cause you to lose any claims. Most motorcycle manufacturers clearly advise against the use of car tires on bikes. If there is sufficient evidence to demonstrate that you intentionally increased the likelihood of an accident by using a car tire, the insurance company will likely deny your claim.
Unless you are driving on a flat surface, manipulating a car tire on your bike can take much more effort than a standard tire. You will likely have to use more brute force to keep the bike upright on sloped roads.
Lastly, using the wrong type of tire can create an overall unsafe situation. You have to guess at the proper inflation point and adjust how the bike handles as a whole. When you are experimenting with complex vehicle specifications outside of a controlled environment, you have the risk of dealing with unforeseen consequences. By using the motorcycle tires prescribed for your bike, you will drastically reduce the potential for massive safety hazards and catastrophic events.