Motorcycle Tire Pressure During the “Dog Days of Summer”
We often hear about the “dog days” of summer. Some say it signifies the hottest days “not fit for a dog,” others claim it’s the weather in which dogs go mad. No matter how the saying came to be, we know that the Dog Days of Summer describe the most oppressive period of summer, between July 3rd and August 11th each year. It just so happens that the 2021 Sturgis Buffalo Chip kicks-off August 6th over the hottest stretch of the Dog Days just before wishing the heat a final “Adiós” when it concludes on August 15th.
With both the Sturgis Rally and the Dog Days just right around the bend, staying cool is on everyone’s mind. With such high temperatures outside, it can make our motorcycles more difficult to safely navigate. When thinking about how to properly maintain our bikes in the heat, the first thing to focus on is the condition of your tires. It may be time to trade in your older set for something new. When you make it to the Chip, stop by Fozzy’s Cycle Shop at the Crossroads. During the rally, you’ll be able to get a nice deal on a new set of Continental ContiTour tires with a 30-day satisfaction guarantee and 3-years of FREE Flat tire road assistance. We bring you more information.
Tire Maintenance 101
According to Shane Conley with How2Wrench on Youtube, “One of the most important tire routines you can perform is inspecting your tire to make sure you are getting the maximum life and mileage from your wheels.” For maximum benefit, tires must be maintained properly to avoid tire damage and abuse that may result in tire disablement. The service life of a tire is a cumulative function of the storage, rotation and service conditions, which a tire is subjected to throughout its life (load, speed, inflation pressure, road hazard injury, etc.). Since service conditions vary widely, accurately predicting the service life of any specific tire in chronological time or mileage isn’t possible.
Tire Pressure is one of the easiest, yet most overlooked maintenance routines you can perform to extend the life of your tire. Why is it necessary to check your tire pressure frequently over the summer? If we haven’t been clear so far, our main challenge with tire pressure over the summer is Heat!
Heat can have a huge effect on your tires. The air pressure in tires increases as the temperature goes up and when you’re planning your trip to the Buffalo Chip, you are going to be contending with lots of heat. Therefore, you must be alert and on top of constant pressure and temperature changes. If you aren’t careful around tire pressure, the motorcycle’s behavior could change and become a safety concern.
Understanding Tire Pressure
Changes of pressure are based on principles of physics that only our scientists at the Continental tire factory in Kobach, Germany really understand. For our purposes, it is important to understand that pressure can be measured using different units of measure such as BAR or PSI and the increase or decrease of air volume. Pounds per square inch (PSI) is the primary unit of measurement in North America.
When it comes to tires, the way it works is the air inside the tire is trapped, so we (us riders), can increase or decrease pressure as the tire expands and contracts. As pressure rises, particles of air strike against the inside tire walls as they have less space due to the fact that they are being pushed; this is where tire swelling is occurring. When temperatures change, this process becomes more complex because air, which is a gas, expands when it is hot and contracts when temperatures are cold.
Ultimately, there are physical laws that explain the behavior of air pressure and temperature in the tires, but we won’t go more into depth here, just the basics are necessary to understand the concept. If you’re really interested in expanding your knowledge, you can research Boyle’s Law, Gay-Lussac Law or the Archimedes Principle; Archimedes, by the way, is the guy that invented a Death Ray to battle the Romans.
Back to tire pressure. The recommended cold tire pressure for your tire is always clearly displayed on your tires sidewall. So finding your manufacturers recommendation is fairly simple. For example, the Cold Tire Pressure for a rear ContiTour tire is 40 PSI.
The rule of thumb is that for every 5° temperature difference, tire pressure will become around 2% higher or 2% lower depending on temperature. In summer, especially in mountain areas, very high temperatures can be reached during the day while they can be very low at night, with a difference of up to 20°.
That means tire pressure can vary up to 8%. With so much temperature difference over a day it is important to check tire pressures at the beginning of the day when the tire is cool (before riding more than 2 miles). Apart from ambient temperature, heat by friction should also be accounted for altering tire pressure. Friction transmits heat to the inside of the tire, increasing in many occasions by 2.9 to 5.8 psi.
Even though a two to eight percent tire pressure may not sound like much on paper, remember that manufacturers advise a specific pressure number in order to extract the maximum performance of the tire in every aspect, so it is crucial in real life situations.
Small deviations directly influence a bike’s behavior. If pressure is higher than suggested, handling, grip levels, leaning ability and tire wear can be negatively affected. Excessive rear wheel spin under acceleration, ultra-sensitive lateral movements and abrupt turn-in can be some expected characteristics on an over inflated tire.
As always, check your bikes user manual for additional recommendations about tire pressure.
The Valve Cap – Little Piece : Big Impact
The main purpose of your valve caps is to help keep dust and dirt out of the valve. Even that may not sound like a particularly glamorous job, but if particles get jammed in the sealing surfaces, your tubes can develop a leak. They can even get clogged enough to not allow a proper connection with your pump. Centrifugal force can also cause your tire valve to open and allowing air to escape- a proper valve cap with an o-ring seal can prevent this air lose.
A dirty valve degrades and loses air much faster. If you’ve ever had a tire or tube with a slow leak, that seems to hold air initially but loses pressure rather quickly, it’s most likely a leaky valve. Once the valve is compromised, there’s nothing you can do but replace the valve stem or tube.
So keep track of those valve caps, especially if you ride in bad conditions, all weather, or off-road.
Happy Trails with a New Set of ContiTour’s
After making the trek to Sturgis during the heat of summer, it might be time for a change. Continental Tires is offering attendees the opportunity to swap your older tires for a fresh pair for the journey home. It’s fitting, then, that Continental Motorcycle Tires has renewed its partnership with the legendary venue, making the ContiTour tire with its 60-Day Rider Satisfaction Guarantee and 3-years of FREE Flat Tire Assistance, the Official Tire of Sturgis Buffalo Chip.
The ContiTour has been completely redesigned, including the addition of Continental’s MileagePlus technology in the compound, which offers improved durability while maintaining exceptional handling characteristics. Designed for heavier models and high mileage, the ContiTour features Continental’s MaxComfort, which provides a smooth, easy ride while maintaining the correct tire shape and balance over long distances, even when the bike has two riders and is fully loaded. If it rains, the tread pattern provides efficient drainage for continued grip and confidence.
All of that means packing up and heading home from Sturgis will be no problem. Hello to a fresh set of tires and so long to the Dog Days of Summer!
Special thank you to Shane Conley with How2Wrench on Youtube for the lesson on Tire Pressure. Be sure to follow How2Wrench for more motorcycle maintenance tips and tricks. You can watch the video below.
And follow Continental Motorcycle tires on Youtube for the latest information on the ContiTour Custom touring Tire and more
See you at the Chip!